TY - JOUR
A1 - Mattern, Maximilian
A1 - Pudell, Jan-Etienne
A1 - Dumesnil, Karine
A1 - Reppert, Alexander von
A1 - Bargheer, Matias
T1 - Towards shaping picosecond strain pulses via magnetostrictive transducers
JF - Photoacoustics
N2 - Using time-resolved x-ray diffraction, we demonstrate the manipulation of the picosecond strain response of a metallic heterostructure consisting of a dysprosium (Dy) transducer and a niobium (Nb) detection layer by an external magnetic field. We utilize the first-order ferromagnetic–antiferromagnetic phase transition of the Dy layer, which provides an additional large contractive stress upon laser excitation compared to its zerofield response. This enhances the laser-induced contraction of the transducer and changes the shape of the picosecond strain pulses driven in Dy and detected within the buried Nb layer. Based on our experiment with rare-earth metals we discuss required properties for functional transducers, which may allow for novel field-control of the emitted picosecond strain pulses.
KW - picosecond ultrasonics
KW - magnetostriction
KW - ultrafast x-ray diffraction
KW - ultrafast photoacoustics
KW - nanoscale heat transfer
KW - negative thermal expansion
Y1 - 2023
U6 - https://doi.org/10.1016/j.pacs.2023.100463
SN - 2213-5979
VL - 30
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Brinkmann, Kai Oliver
A1 - Becker, Tim
A1 - Zimmermann, Florian
A1 - Kreusel, Cedric
A1 - Gahlmann, Tobias
A1 - Theisen, Manuel
A1 - Haeger, Tobias
A1 - Olthof, Selina
A1 - Tückmantel, Christian
A1 - Günster, M.
A1 - Maschwitz, Timo
A1 - Göbelsmann, Fabian
A1 - Koch, Christine
A1 - Hertel, Dirk
A1 - Caprioglio, Pietro
A1 - Peña-Camargo, Francisco
A1 - Perdigón-Toro, Lorena
A1 - Al-Ashouri, Amran
A1 - Merten, Lena
A1 - Hinderhofer, Alexander
A1 - Gomell, Leonie
A1 - Zhang, Siyuan
A1 - Schreiber, Frank
A1 - Albrecht, Steve
A1 - Meerholz, Klaus
A1 - Neher, Dieter
A1 - Stolterfoht, Martin
A1 - Riedl, Thomas
T1 - Perovskite-organic tandem solar cells with indium oxide interconnect
JF - Nature
N2 - Multijunction solar cells can overcome the fundamental efficiency limits of single-junction devices. The bandgap tunability of metal halide perovskite solar cells renders them attractive for multijunction architectures(1). Combinations with silicon and copper indium gallium selenide (CIGS), as well as all-perovskite tandem cells, have been reported(2-5). Meanwhile, narrow-gap non-fullerene acceptors have unlocked skyrocketing efficiencies for organic solar cells(6,7). Organic and perovskite semiconductors are an attractive combination, sharing similar processing technologies. Currently, perovskite-organic tandems show subpar efficiencies and are limited by the low open-circuit voltage (V-oc) of wide-gap perovskite cells(8) and losses introduced by the interconnect between the subcells(9,10). Here we demonstrate perovskite-organic tandem cells with an efficiency of 24.0 per cent (certified 23.1 per cent) and a high V-oc of 2.15 volts. Optimized charge extraction layers afford perovskite subcells with an outstanding combination of high V-oc and fill factor. The organic subcells provide a high external quantum efficiency in the near-infrared and, in contrast to paradigmatic concerns about limited photostability of non-fullerene cells(11), show an outstanding operational stability if excitons are predominantly generated on the non-fullerene acceptor, which is the case in our tandems. The subcells are connected by an ultrathin (approximately 1.5 nanometres) metal-like indium oxide layer with unprecedented low optical/electrical losses. This work sets a milestone for perovskite-organic tandems, which outperform the best p-i-n perovskite single junctions(12) and are on a par with perovskite-CIGS and all-perovskite multijunctions(13).
Y1 - 2022
U6 - https://doi.org/10.1038/s41586-022-04455-0
SN - 0028-0836
SN - 1476-4687
VL - 604
IS - 7905
SP - 280
EP - 286
PB - Nature Research
CY - Berlin
ER -
TY - JOUR
A1 - Reppert, Alexander von
A1 - Willig, Lisa
A1 - Pudell, Jan-Etienne
A1 - Roessle, M.
A1 - Leitenberger, Wolfram
A1 - Herzog, Marc
A1 - Ganss, F.
A1 - Hellwig, O.
A1 - Bargheer, Matias
T1 - Ultrafast laser generated strain in granular and continuous FePt thin films
JF - Applied physics letters
N2 - We employ ultrafast X-ray diffraction to compare the lattice dynamics of laser-excited continuous and granular FePt films on MgO (100) substrates. Contrary to recent results on free-standing granular films, we observe in both cases a pronounced and long-lasting out-of-plane expansion. We attribute this discrepancy to the in-plane expansion, which is suppressed by symmetry in continuous films. Granular films on substrates are less constrained and already show a reduced out-of-plane contraction. Via the Poisson effect, out-of-plane contractions drive in-plane expansion and vice versa. Consistently, the granular film exhibits a short-lived out-of-plane contraction driven by ultrafast demagnetization which is followed by a reduced and delayed expansion. From the acoustic reflections of the observed strain waves at the film-substrate interface, we extract a 13% reduction of the elastic constants in thin 10 nm FePt films compared to bulk-like samples. (C) 2018 Author(s).
Y1 - 2018
U6 - https://doi.org/10.1063/1.5050234
SN - 0003-6951
SN - 1077-3118
VL - 113
IS - 12
PB - American Institute of Physics
CY - Melville
ER -
TY - GEN
A1 - Ye, Fangyuan
A1 - Zhang, Shuo
A1 - Warby, Jonathan
A1 - Wu, Jiawei
A1 - Gutierrez-Partida, Emilio
A1 - Lang, Felix
A1 - Shah, Sahil
A1 - Saglamkaya, Elifnaz
A1 - Sun, Bowen
A1 - Zu, Fengshuo
A1 - Shoaee, Safa
A1 - Wang, Haifeng
A1 - Stiller, Burkhard
A1 - Neher, Dieter
A1 - Zhu, Wei-Hong
A1 - Stolterfoht, Martin
A1 - Wu, Yongzhen
T1 - Overcoming C₆₀-induced interfacial recombination in inverted perovskite solar cells by electron-transporting carborane
T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Inverted perovskite solar cells still suffer from significant non-radiative recombination losses at the perovskite surface and across the perovskite/C₆₀ interface, limiting the future development of perovskite-based single- and multi-junction photovoltaics. Therefore, more effective inter- or transport layers are urgently required. To tackle these recombination losses, we introduce ortho-carborane as an interlayer material that has a spherical molecular structure and a three-dimensional aromaticity. Based on a variety of experimental techniques, we show that ortho-carborane decorated with phenylamino groups effectively passivates the perovskite surface and essentially eliminates the non-radiative recombination loss across the perovskite/C₆₀ interface with high thermal stability. We further demonstrate the potential of carborane as an electron transport material, facilitating electron extraction while blocking holes from the interface. The resulting inverted perovskite solar cells deliver a power conversion efficiency of over 23% with a low non-radiative voltage loss of 110 mV, and retain >97% of the initial efficiency after 400 h of maximum power point tracking. Overall, the designed carborane based interlayer simultaneously enables passivation, electron-transport and hole-blocking and paves the way toward more efficient and stable perovskite solar cells.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1317
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-587705
SN - 1866-8372
IS - 1317
ER -
TY - JOUR
A1 - Ye, Fangyuan
A1 - Zhang, Shuo
A1 - Warby, Jonathan
A1 - Wu, Jiawei
A1 - Gutierrez-Partida, Emilio
A1 - Lang, Felix
A1 - Shah, Sahil
A1 - Saglamkaya, Elifnaz
A1 - Sun, Bowen
A1 - Zu, Fengshuo
A1 - Shoaee, Safa
A1 - Wang, Haifeng
A1 - Stiller, Burkhard
A1 - Neher, Dieter
A1 - Zhu, Wei-Hong
A1 - Stolterfoht, Martin
A1 - Wu, Yongzhen
T1 - Overcoming C-60-induced interfacial recombination in inverted perovskite solar cells by electron-transporting carborane
JF - Nature Communications
N2 - Inverted perovskite solar cells still suffer from significant non-radiative recombination losses at the perovskite surface and across the perovskite/C-60 interface, limiting the future development of perovskite-based single- and multi-junction photovoltaics. Therefore, more effective inter- or transport layers are urgently required. To tackle these recombination losses, we introduce ortho-carborane as an interlayer material that has a spherical molecular structure and a three-dimensional aromaticity. Based on a variety of experimental techniques, we show that ortho-carborane decorated with phenylamino groups effectively passivates the perovskite surface and essentially eliminates the non-radiative recombination loss across the perovskite/C-60 interface with high thermal stability. We further demonstrate the potential of carborane as an electron transport material, facilitating electron extraction while blocking holes from the interface. The resulting inverted perovskite solar cells deliver a power conversion efficiency of over 23% with a low non-radiative voltage loss of 110mV, and retain >97% of the initial efficiency after 400h of maximum power point tracking. Overall, the designed carborane based interlayer simultaneously enables passivation, electron-transport and hole-blocking and paves the way toward more efficient and stable perovskite solar cells. Effective transport layers are essential to suppress non-radiative recombination losses. Here, the authors introduce phenylamino-functionalized ortho-carborane as an interfacial layer, and realise inverted perovskite solar cells with efficiency of over 23% and operational stability of T97=400h.
Y1 - 2022
U6 - https://doi.org/10.1038/s41467-022-34203-x
SN - 2041-1723
VL - 13
IS - 1
PB - Nature Publishing Group
CY - London
ER -
TY - JOUR
A1 - Pena-Camargo, Francisco
A1 - Thiesbrummel, Jarla
A1 - Hempel, Hannes
A1 - Musiienko, Artem
A1 - Le Corre, Vincent M.
A1 - Diekmann, Jonas
A1 - Warby, Jonathan
A1 - Unold, Thomas
A1 - Lang, Felix
A1 - Neher, Dieter
A1 - Stolterfoht, Martin
T1 - Revealing the doping density in perovskite solar cells and its impact on device performance
JF - Applied physics reviews
N2 - Traditional inorganic semiconductors can be electronically doped with high precision. Conversely, there is still conjecture regarding the assessment of the electronic doping density in metal-halide perovskites, not to mention of a control thereof. This paper presents a multifaceted approach to determine the electronic doping density for a range of different lead-halide perovskite systems. Optical and electrical characterization techniques, comprising intensity-dependent and transient photoluminescence, AC Hall effect, transfer-length-methods, and charge extraction measurements were instrumental in quantifying an upper limit for the doping density. The obtained values are subsequently compared to the electrode charge per cell volume under short-circuit conditions ( CUbi/eV), which amounts to roughly 10(16) cm(-3). This figure of merit represents the critical limit below which doping-induced charges do not influence the device performance. The experimental results consistently demonstrate that the doping density is below this critical threshold 10(12) cm(-3), which means << CUbi / e V) for all common lead-based metal-halide perovskites. Nevertheless, although the density of doping-induced charges is too low to redistribute the built-in voltage in the perovskite active layer, mobile ions are present in sufficient quantities to create space-charge-regions in the active layer, reminiscent of doped pn-junctions. These results are well supported by drift-diffusion simulations, which confirm that the device performance is not affected by such low doping densities.
Y1 - 2022
U6 - https://doi.org/10.1063/5.0085286
SN - 1931-9401
VL - 9
IS - 2
PB - AIP Publishing
CY - Melville
ER -
TY - JOUR
A1 - Mattern, Maximilian
A1 - Reppert, Alexander von
A1 - Zeuschner, Steffen Peer
A1 - Pudell, Jan-Etienne
A1 - Kühne, F.
A1 - Diesing, Detlef
A1 - Herzog, Marc
A1 - Bargheer, Matias
T1 - Electronic energy transport in nanoscale Au/Fe hetero-structures in the perspective of ultrafast lattice dynamics
JF - Applied physics letters
N2 - We study the ultrafast electronic transport of energy in a photoexcited nanoscale Au/Fe hetero-structure by modeling the spatiotemporal profile of energy densities that drives transient strain, which we quantify by femtosecond x-ray diffraction. This flow of energy is relevant for intrinsic demagnetization and ultrafast spin transport. We measured lattice strain for different Fe layer thicknesses ranging from few atomic layers to several nanometers and modeled the spatiotemporal flow of energy densities. The combination of a high electron-phonon coupling coefficient and a large Sommerfeld constant in Fe is found to yield electronic transfer of nearly all energy from Au to Fe within the first hundreds of femtoseconds.
Y1 - 2022
U6 - https://doi.org/10.1063/5.0080378
SN - 0003-6951
SN - 1077-3118
VL - 120
IS - 9
PB - AIP Publishing
CY - Melville
ER -
TY - JOUR
A1 - Reppert, Alexander von
A1 - Puddell, J.
A1 - Koc, A.
A1 - Reinhardt, M.
A1 - Leitenberger, Wolfram
A1 - Dumesnil, K.
A1 - Zamponi, Flavio
A1 - Bargheer, Matias
T1 - Persistent nonequilibrium dynamics of the thermal energies in the spin and phonon systems of an antiferromagnet
JF - Structural dynamics
N2 - We present a temperature and fluence dependent Ultrafast X-Ray Diffraction study of a laser-heated antiferromagnetic dysprosium thin film. The loss of antiferromagnetic order is evidenced by a pronounced lattice contraction. We devise a method to determine the energy flow between the phonon and spin system from calibrated Bragg peak positions in thermal equilibrium. Reestablishing the magnetic order is much slower than the cooling of the lattice, especially around the Néel temperature. Despite the pronounced magnetostriction, the transfer of energy from the spin system to the phonons in Dy is slow after the spin-order is lost.
Y1 - 2016
U6 - https://doi.org/10.1063/1.4961253
SN - 2329-7778
VL - 3
PB - AIP Publishing LLC
CY - Melville, NY
ER -
TY - JOUR
A1 - Le Corre, Vincent M.
A1 - Diekmann, Jonas
A1 - Peña-Camargo, Francisco
A1 - Thiesbrummel, Jarla
A1 - Tokmoldin, Nurlan
A1 - Gutierrez-Partida, Emilio
A1 - Peters, Karol Pawel
A1 - Perdigón-Toro, Lorena
A1 - Futscher, Moritz H.
A1 - Lang, Felix
A1 - Warby, Jonathan
A1 - Snaith, Henry J.
A1 - Neher, Dieter
A1 - Stolterfoht, Martin
T1 - Quantification of efficiency losses due to mobile ions in Perovskite solar cells via fast hysteresis measurements
JF - Solar RRL
N2 - Perovskite semiconductors differ from most inorganic and organic semiconductors due to the presence of mobile ions in the material. Although the phenomenon is intensively investigated, important questions such as the exact impact of the mobile ions on the steady-state power conversion efficiency (PCE) and stability remain. Herein, a simple method is proposed to estimate the efficiency loss due to mobile ions via "fast-hysteresis" measurements by preventing the perturbation of mobile ions out of their equilibrium position at fast scan speeds (approximate to 1000 V s(-1)). The "ion-free" PCE is between 1% and 3% higher than the steady-state PCE, demonstrating the importance of ion-induced losses, even in cells with low levels of hysteresis at typical scan speeds (approximate to 100mv s(-1)). The hysteresis over many orders of magnitude in scan speed provides important information on the effective ion diffusion constant from the peak hysteresis position. The fast-hysteresis measurements are corroborated by transient charge extraction and capacitance measurements and numerical simulations, which confirm the experimental findings and provide important insights into the charge carrier dynamics. The proposed method to quantify PCE losses due to field screening induced by mobile ions clarifies several important experimental observations and opens up a large range of future experiments.
KW - hysteresis
KW - mobile ions
KW - perovskite solar cells
Y1 - 2021
U6 - https://doi.org/10.1002/solr.202100772
SN - 2367-198X
VL - 6
IS - 4
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Zeiske, Stefan
A1 - Sandberg, Oskar J.
A1 - Zarrabi, Nasim
A1 - Wolff, Christian Michael
A1 - Raoufi, Meysam
A1 - Peña-Camargo, Francisco
A1 - Gutierrez-Partida, Emilio
A1 - Meredith, Paul
A1 - Stolterfoht, Martin
A1 - Armin, Ardalan
T1 - Static disorder in lead halide perovskites
JF - The journal of physical chemistry letters
N2 - In crystalline and amorphous semiconductors, the temperature-dependent Urbach energy can be determined from the inverse slope of the logarithm of the absorption spectrum and reflects the static and dynamic energetic disorder. Using recent advances in the sensitivity of photocurrent spectroscopy methods, we elucidate the temperature-dependent Urbach energy in lead halide perovskites containing different numbers of cation components. We find Urbach energies at room temperature to be 13.0 +/- 1.0, 13.2 +/- 1.0, and 13.5 +/- 1.0 meV for single, double, and triple cation perovskite. Static, temperature-independent contributions to the Urbach energy are found to be as low as 5.1 ?+/- 0.5, 4.7 +/- 0.3, and 3.3 +/- 0.9 meV for the same systems. Our results suggest that, at a low temperature, the dominant static disorder in perovskites is derived from zero-point phonon energy rather than structural disorder. This is unusual for solution-processed semiconductors but broadens the potential application of perovskites further to quantum electronics and devices.
KW - Cations
KW - External quantum efficiency
KW - Perovskites
KW - Solar cells
KW - Solar energy
Y1 - 2022
U6 - https://doi.org/10.1021/acs.jpclett.2c01652
SN - 1948-7185
VL - 13
IS - 31
SP - 7280
EP - 7285
PB - American Chemical Society
CY - Washington
ER -
TY - JOUR
A1 - Cervantes Villa, Juan Sebastian
A1 - Shprits, Yuri Y.
A1 - Aseev, Nikita
A1 - Drozdov, Alexander
A1 - Castillo Tibocha, Angelica Maria
A1 - Stolle, Claudia
T1 - Identifying radiation belt electron source and loss processes by assimilating spacecraft data in a three-dimensional diffusion model
JF - Journal of geophysical research : Space physics
N2 - Data assimilation aims to blend incomplete and inaccurate data with physics-based dynamical models. In the Earth's radiation belts, it is used to reconstruct electron phase space density, and it has become an increasingly important tool in validating our current understanding of radiation belt dynamics, identifying new physical processes, and predicting the near-Earth hazardous radiation environment. In this study, we perform reanalysis of the sparse measurements from four spacecraft using the three-dimensional Versatile Electron Radiation Belt diffusion model and a split-operator Kalman filter over a 6-month period from 1 October 2012 to 1 April 2013. In comparison to previous works, our 3-D model accounts for more physical processes, namely, mixed pitch angle-energy diffusion, scattering by Electromagnetic Ion Cyclotron waves, and magnetopause shadowing. We describe how data assimilation, by means of the innovation vector, can be used to account for missing physics in the model. We use this method to identify the radial distances from the Earth and the geomagnetic conditions where our model is inconsistent with the measured phase space density for different values of the invariants mu and K. As a result, the Kalman filter adjusts the predictions in order to match the observations, and we interpret this as evidence of where and when additional source or loss processes are active. The current work demonstrates that 3-D data assimilation provides a comprehensive picture of the radiation belt electrons and is a crucial step toward performing reanalysis using measurements from ongoing and future missions.
KW - acceleration
KW - code
KW - density
KW - emic waves
KW - energetic particle
KW - mechanisms
KW - reanalysis
KW - ultrarelativistic electrons
KW - weather
Y1 - 2019
U6 - https://doi.org/10.1029/2019JA027514
SN - 2169-9380
SN - 2169-9402
VL - 125
IS - 1
PB - American Geophysical Union
CY - Washington
ER -
TY - JOUR
A1 - Pudell, Jan-Etienne
A1 - Maznev, A. A.
A1 - Herzog, Marc
A1 - Kronseder, M.
A1 - Back, Christian H.
A1 - Malinowski, Gregory
A1 - Reppert, Alexander von
A1 - Bargheer, Matias
T1 - Layer specific observation of slow thermal equilibration in ultrathin metallic nanostructures by femtosecond X-ray diffraction
JF - Nature Communications
N2 - Ultrafast heat transport in nanoscale metal multilayers is of great interest in the context of optically induced demagnetization, remagnetization and switching. If the penetration depth of light exceeds the bilayer thickness, layer-specific information is unavailable from optical probes. Femtosecond diffraction experiments provide unique experimental access to heat transport over single digit nanometer distances. Here, we investigate the structural response and the energy flow in the ultrathin double-layer system: gold on ferromagnetic nickel. Even though the excitation pulse is incident from the Au side, we observe a very rapid heating of the Ni lattice, whereas the Au lattice initially remains cold. The subsequent heat transfer from Ni to the Au lattice is found to be two orders of magnitude slower than predicted by the conventional heat equation and much slower than electron-phonon coupling times in Au. We present a simplified model calculation highlighting the relevant thermophysical quantities.
Y1 - 2018
U6 - https://doi.org/10.1038/s41467-018-05693-5
SN - 2041-1723
VL - 9
PB - Nature Publ. Group
CY - London
ER -
TY - JOUR
A1 - Pudell, Jan-Etienne
A1 - Reppert, Alexander von
A1 - Schick, D.
A1 - Zamponi, F.
A1 - Rössle, Matthias
A1 - Herzog, Marc
A1 - Zabel, Hartmut
A1 - Bargheer, Matias
T1 - Ultrafast negative thermal expansion driven by spin disorder
JF - Physical review : B, Condensed matter and materials physics
N2 - We measure the transient strain profile in a nanoscale multilayer system composed of yttrium, holmium, and niobium after laser excitation using ultrafast x-ray diffraction. The strain propagation through each layer is determined by transient changes in the material-specific Bragg angles. We experimentally derive the exponentially decreasing stress profile driving the strain wave and show that it closely matches the optical penetration depth. Below the Neel temperature of Ho, the optical excitation triggers negative thermal expansion, which is induced by a quasi-instantaneous contractive stress and a second contractive stress contribution increasing on a 12-ps timescale. These two timescales were recently measured for the spin disordering in Ho [Rettig et al., Phys. Rev. Lett. 116, 257202 (2016)]. As a consequence, we observe an unconventional bipolar strain pulse with an inverted sign traveling through the heterostructure.
Y1 - 2019
U6 - https://doi.org/10.1103/PhysRevB.99.094304
SN - 2469-9950
SN - 2469-9969
VL - 99
IS - 9
PB - American Physical Society
CY - College Park
ER -
TY - JOUR
A1 - Doerries, Timo J.
A1 - Chechkin, Aleksei
A1 - Schumer, Rina
A1 - Metzler, Ralf
T1 - Rate equations, spatial moments, and concentration profiles for mobile-immobile models with power-law and mixed waiting time distributions
JF - Physical review : E, Statistical, nonlinear and soft matter physics
N2 - We present a framework for systems in which diffusion-advection transport of a tracer substance in a mobile zone is interrupted by trapping in an immobile zone.
Our model unifies different model approaches based on distributed-order diffusion equations, exciton diffusion rate models, and random-walk models for multirate mobile-immobile mass transport.
We study various forms for the trapping time dynamics and their effects on the tracer mass in the mobile zone.
Moreover, we find the associated breakthrough curves, the tracer density at a fixed point in space as a function of time, and the mobile and immobile concentration profiles and the respective moments of the transport.
Specifically, we derive explicit forms for the anomalous transport dynamics and an asymptotic power-law decay of the mobile mass for a Mittag-Leffler trapping time distribution.
In our analysis we point out that even for exponential trapping time densities, transient anomalous transport is observed.
Our results have direct applications in geophysical contexts, but also in biological, soft matter, and solid state systems.
Y1 - 2022
U6 - https://doi.org/10.1103/PhysRevE.105.014105
SN - 2470-0045
SN - 2470-0053
VL - 105
IS - 1
PB - The American Institute of Physics
CY - Woodbury, NY
ER -
TY - GEN
A1 - Wang, Qiong
A1 - Smith, Joel A.
A1 - Skroblin, Dieter
A1 - Steele, Julian A.
A1 - Wolff, Christian Michael
A1 - Caprioglio, Pietro
A1 - Stolterfoht, Martin
A1 - Köbler, Hans
A1 - Turren-Cruz, Silver-Hamill
A1 - Li, Meng
A1 - Gollwitzer, Christian
A1 - Neher, Dieter
A1 - Abate, Antonio
T1 - Managing phase purities and crystal orientation for high-performance and photostable cesium lead halide perovskite solar cells
T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2 - Inorganic perovskites with cesium (Cs+) as the cation have great potential as photovoltaic materials if their phase purity and stability can be addressed. Herein, a series of inorganic perovskites is studied, and it is found that the power conversion efficiency of solar cells with compositions CsPbI1.8Br1.2, CsPbI2.0Br1.0, and CsPbI2.2Br0.8 exhibits a high dependence on the initial annealing step that is found to significantly affect the crystallization and texture behavior of the final perovskite film. At its optimized annealing temperature, CsPbI1.8Br1.2 exhibits a pure orthorhombic phase and only one crystal orientation of the (110) plane. Consequently, this allows for the best efficiency of up to 14.6% and the longest operational lifetime, T-S80, of approximate to 300 h, averaged of over six solar cells, during the maximum power point tracking measurement under continuous light illumination and nitrogen atmosphere. This work provides essential progress on the enhancement of photovoltaic performance and stability of CsPbI3 - xBrx perovskite solar cells.
T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1210
KW - cesium lead halides
KW - crystal orientation
KW - inorganic perovskites
KW - ISOS-L-1I protocol
KW - phase purity
KW - photostability
Y1 - 2020
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-525374
SN - 1866-8372
IS - 9
ER -
TY - JOUR
A1 - Di Bello, Costantino
A1 - Hartmann, Alexander K.
A1 - Majumdar, Satya N.
A1 - Mori, Francesco
A1 - Rosso, Alberto
A1 - Schehr, Gregory
T1 - Current fluctuations in stochastically resetting particle systems
JF - Physical review : E, Statistical, nonlinear and soft matter physics
N2 - We consider a system of noninteracting particles on a line with initial positions distributed uniformly with density ? on the negative half-line. We consider two different models: (i) Each particle performs independent Brownian motion with stochastic resetting to its initial position with rate r and (ii) each particle performs run -and-tumble motion, and with rate r its position gets reset to its initial value and simultaneously its velocity gets randomized. We study the effects of resetting on the distribution P(Q, t) of the integrated particle current Q up to time t through the origin (from left to right). We study both the annealed and the quenched current distributions and in both cases, we find that resetting induces a stationary limiting distribution of the current at long times. However, we show that the approach to the stationary state of the current distribution in the annealed and the quenched cases are drastically different for both models. In the annealed case, the whole distribution P-an(Q, t) approaches its stationary limit uniformly for all Q. In contrast, the quenched distribution P-qu(Q, t) attains its stationary form for Q < Q(crit)(t), while it remains time dependent for Q > Q(crit)(t). We show that Q(crit)(t) increases linearly with t for large t. On the scale where Q <; Q(crit)(t), we show that P-qu(Q, t) has an unusual large deviation form with a rate function that has a third-order phase transition at the critical point. We have computed the associated rate functions analytically for both models. Using an importance sampling method that allows to probe probabilities as tiny as 10-14000, we were able to compute numerically this nonanalytic rate function for the resetting Brownian dynamics and found excellent agreement with our analytical prediction.
Y1 - 2023
U6 - https://doi.org/10.1103/PhysRevE.108.014112
SN - 2470-0045
SN - 2470-0053
VL - 108
IS - 1
PB - American Physical Society
CY - College Park
ER -
TY - JOUR
A1 - Abdalla, H.
A1 - Adam, R.
A1 - Aharonian, Felix A.
A1 - Benkhali, F. Ait
A1 - Angüner, Ekrem Oǧuzhan
A1 - Arcaro, C.
A1 - Armand, C.
A1 - Armstrong, T.
A1 - Ashkar, H.
A1 - Backes, M.
A1 - Baghmanyan, V.
A1 - Martins, V. Barbosa
A1 - Barnacka, A.
A1 - Barnard, M.
A1 - Becherini, Y.
A1 - Berge, D.
A1 - Bernlohr, K.
A1 - Bi, B.
A1 - Bottcher, M.
A1 - Boisson, C.
A1 - Bolmont, J.
A1 - de Lavergne, M. de Bony
A1 - Bordas, Pol
A1 - Breuhaus, M.
A1 - Brun, F.
A1 - Brun, P.
A1 - Bryan, M.
A1 - Buchele, M.
A1 - Bulik, T.
A1 - Bylund, T.
A1 - Caroff, S.
A1 - Carosi, A.
A1 - Casanova, Sabrina
A1 - Chand, T.
A1 - Chandra, S.
A1 - Chen, A.
A1 - Cotter, G.
A1 - Curylo, M.
A1 - Mbarubucyeye, J. Damascene
A1 - Davids, I. D.
A1 - Davies, J.
A1 - Deil, C.
A1 - Devin, J.
A1 - deWilt, P.
A1 - Dirson, L.
A1 - Djannati-Atai, A.
A1 - Dmytriiev, A.
A1 - Donath, A.
A1 - Doroshenko, V.
A1 - Duffy, C.
A1 - Dyks, J.
A1 - Egberts, Kathrin
A1 - Eichhorn, F.
A1 - Einecke, S.
A1 - Emery, G.
A1 - Ernenwein, J. -P.
A1 - Feijen, K.
A1 - Fegan, S.
A1 - Fiasson, A.
A1 - de Clairfontaine, G. Fichet
A1 - Fontaine, G.
A1 - Funk, S.
A1 - Fussling, Matthias
A1 - Gabici, S.
A1 - Gallant, Y. A.
A1 - Giavitto, G.
A1 - Giunti, L.
A1 - Glawion, D.
A1 - Glicenstein, J. F.
A1 - Gottschall, D.
A1 - Grondin, M. -H.
A1 - Hahn, J.
A1 - Haupt, M.
A1 - Hermann, G.
A1 - Hinton, J. A.
A1 - Hofmann, W.
A1 - Hoischen, Clemens
A1 - Holch, T. L.
A1 - Holler, M.
A1 - Horbe, M.
A1 - Horns, D.
A1 - Huber, D.
A1 - Jamrozy, M.
A1 - Jankowsky, D.
A1 - Jankowsky, F.
A1 - Jardin-Blicq, A.
A1 - Joshi, V.
A1 - Jung-Richardt, I.
A1 - Kasai, E.
A1 - Kastendieck, M. A.
A1 - Katarzynski, K.
A1 - Katz, U.
A1 - Khangulyan, D.
A1 - Khelifi, B.
A1 - Klepser, S.
A1 - Kluzniak, W.
A1 - Komin, Nu.
A1 - Konno, R.
A1 - Kosack, K.
A1 - Kostunin, D.
A1 - Kreter, M.
A1 - Lamanna, G.
A1 - Lemiere, A.
A1 - Lemoine-Goumard, M.
A1 - Lenain, J. -P.
A1 - Levy, C.
A1 - Lohse, T.
A1 - Lypova, I.
A1 - Mackey, J.
A1 - Majumdar, J.
A1 - Malyshev, D.
A1 - Malyshev, D.
A1 - Marandon, V.
A1 - Marchegiani, P.
A1 - Marcowith, Alexandre
A1 - Mares, A.
A1 - Marti-Devesa, G.
A1 - Marx, R.
A1 - Maurin, G.
A1 - Meintjes, P. J.
A1 - Meyer, M.
A1 - Mitchell, A.
A1 - Moderski, R.
A1 - Mohamed, M.
A1 - Mohrmann, L.
A1 - Montanari, A.
A1 - Moore, C.
A1 - Morris, P.
A1 - Moulin, Emmanuel
A1 - Muller, J.
A1 - Murach, T.
A1 - Nakashima, K.
A1 - Nayerhoda, A.
A1 - de Naurois, M.
A1 - Ndiyavala, H.
A1 - Niederwanger, F.
A1 - Niemiec, J.
A1 - Oakes, L.
A1 - O'Brien, Patrick
A1 - Odaka, H.
A1 - Ohm, S.
A1 - Olivera-Nieto, L.
A1 - Wilhelmi, E. de Ona
A1 - Ostrowski, M.
A1 - Oya, I.
A1 - Panter, M.
A1 - Panny, S.
A1 - Parsons, R. D.
A1 - Peron, G.
A1 - Peyaud, B.
A1 - Piel, Q.
A1 - Pita, S.
A1 - Poireau, V.
A1 - Noel, A. Priyana
A1 - Prokhorov, D. A.
A1 - Prokoph, H.
A1 - Puhlhofer, G.
A1 - Punch, M.
A1 - Quirrenbach, A.
A1 - Raab, S.
A1 - Rauth, R.
A1 - Reichherzer, P.
A1 - Reimer, A.
A1 - Reimer, O.
A1 - Remy, Q.
A1 - Renaud, M.
A1 - Rieger, F.
A1 - Rinchiuso, L.
A1 - Romoli, C.
A1 - Rowell, G.
A1 - Rudak, B.
A1 - Ruiz-Velasco, E.
A1 - Sahakian, V.
A1 - Sailer, S.
A1 - Sanchez, D. A.
A1 - Santangelo, Andrea
A1 - Sasaki, M.
A1 - Scalici, M.
A1 - Schussler, F.
A1 - Schutte, H. M.
A1 - Schwanke, U.
A1 - Schwemmer, S.
A1 - Seglar-Arroyo, M.
A1 - Senniappan, M.
A1 - Seyffert, A. S.
A1 - Shafi, N.
A1 - Shiningayamwe, K.
A1 - Simoni, R.
A1 - Sinha, A.
A1 - Sol, H.
A1 - Specovius, A.
A1 - Spencer, S.
A1 - Spir-Jacob, M.
A1 - Stawarz, L.
A1 - Sun, L.
A1 - Steenkamp, R.
A1 - Stegmann, C.
A1 - Steinmassl, S.
A1 - Steppa, C.
A1 - Takahashi, T.
A1 - Tavernier, T.
A1 - Taylor, A. M.
A1 - Terrier, R.
A1 - Tiziani, D.
A1 - Tluczykont, M.
A1 - Tomankova, L.
A1 - Trichard, C.
A1 - Tsirou, M.
A1 - Tuffs, R.
A1 - Uchiyama, Y.
A1 - van der Walt, D. J.
A1 - van Eldik, C.
A1 - van Rensburg, C.
A1 - van Soelen, B.
A1 - Vasileiadis, G.
A1 - Veh, J.
A1 - Venter, C.
A1 - Vincent, P.
A1 - Vink, J.
A1 - Volk, H. J.
A1 - Vuillaume, T.
A1 - Wadiasingh, Z.
A1 - Wagner, S. J.
A1 - Watson, J.
A1 - Werner, F.
A1 - White, R.
A1 - Wierzcholska, A.
A1 - Wong, Yu Wun
A1 - Yusafzai, A.
A1 - Zacharias, M.
A1 - Zanin, R.
A1 - Zargaryan, D.
A1 - Zdziarski, A. A.
A1 - Zech, Alraune
A1 - Zhu, S. J.
A1 - Ziegler, A.
A1 - Zorn, J.
A1 - Zouari, S.
A1 - Zywucka, N.
T1 - An extreme particle accelerator in the Galactic plane
BT - HESS J1826-130
JF - Astronomy and astrophysics : an international weekly journal
N2 - The unidentified very-high-energy (VHE; E > 0.1 TeV) gamma -ray source, HESS J1826-130, was discovered with the High Energy Stereoscopic System (HESS) in the Galactic plane. The analysis of 215 h of HESS data has revealed a steady gamma -ray flux from HESS J1826-130, which appears extended with a half-width of 0.21 degrees +/- 0.02
(stat)degrees
stat degrees +/- 0.05
(sys)degrees sys degrees . The source spectrum is best fit with either a power-law function with a spectral index Gamma = 1.78 +/- 0.10(stat) +/- 0.20(sys) and an exponential cut-off at 15.2
(+5.5)(-3.2) -3.2+5.5 TeV, or a broken power-law with Gamma (1) = 1.96 +/- 0.06(stat) +/- 0.20(sys), Gamma (2) = 3.59 +/- 0.69(stat) +/- 0.20(sys) for energies below and above E-br = 11.2 +/- 2.7 TeV, respectively. The VHE flux from HESS J1826-130 is contaminated by the extended emission of the bright, nearby pulsar wind nebula, HESS J1825-137, particularly at the low end of the energy spectrum. Leptonic scenarios for the origin of HESS J1826-130 VHE emission related to PSR J1826-1256 are confronted by our spectral and morphological analysis. In a hadronic framework, taking into account the properties of dense gas regions surrounding HESS J1826-130, the source spectrum would imply an astrophysical object capable of accelerating the parent particle population up to greater than or similar to 200 TeV. Our results are also discussed in a multiwavelength context, accounting for both the presence of nearby supernova remnants, molecular clouds, and counterparts detected in radio, X-rays, and TeV energies.
KW - ISM: supernova remnants
KW - ISM: clouds
KW - gamma rays: general
KW - gamma rays:
KW - ISM
Y1 - 2020
U6 - https://doi.org/10.1051/0004-6361/202038851
SN - 0004-6361
SN - 1432-0746
VL - 644
PB - EDP Sciences
CY - Les Ulis
ER -
TY - JOUR
A1 - Abdalla, Hassan E.
A1 - Abramowski, A.
A1 - Aharonian, Felix A.
A1 - Benkhali, F. Ait
A1 - Akhperjanian, A. G.
A1 - Andersson, T.
A1 - Anguener, E. O.
A1 - Arrieta, M.
A1 - Aubert, P.
A1 - Backes, M.
A1 - Balzer, A.
A1 - Barnard, M.
A1 - Becherini, Y.
A1 - Tjus, J. Becker
A1 - Berge, D.
A1 - Bernhard, S.
A1 - Bernloehr, K.
A1 - Blackwell, R.
A1 - Boettcher, M.
A1 - Boisson, C.
A1 - Bolmont, J.
A1 - Bordas, Pol
A1 - Bregeon, J.
A1 - Brun, F.
A1 - Brun, P.
A1 - Bryan, M.
A1 - Bulik, T.
A1 - Capasso, M.
A1 - Carr, J.
A1 - Carrigan, S.
A1 - Casanova, Sabrina
A1 - Cerruti, M.
A1 - Chakraborty, N.
A1 - Chalme-Calvet, R.
A1 - Chaves, R. C. G.
A1 - Chen, A.
A1 - Chevalier, J.
A1 - Chretien, M.
A1 - Colafrancesco, S.
A1 - Cologna, G.
A1 - Condon, B.
A1 - Conrad, J.
A1 - Couturier, C.
A1 - Cui, Y.
A1 - Davids, I. D.
A1 - Degrange, B.
A1 - Deil, C.
A1 - Devin, J.
A1 - dewilt, P.
A1 - Dirson, L.
A1 - Djannati-Atai, A.
A1 - Domainko, W.
A1 - Donath, A.
A1 - Dubus, G.
A1 - Dutson, K.
A1 - Dyks, J.
A1 - Edwards, T.
A1 - Egberts, Kathrin
A1 - Eger, P.
A1 - Ernenwein, J. -P.
A1 - Eschbach, S.
A1 - Farnier, C.
A1 - Fegan, S.
A1 - Fernandes, M. V.
A1 - Fiasson, A.
A1 - Fontaine, G.
A1 - Foerster, A.
A1 - Funk, S.
A1 - Fuessling, M.
A1 - Gabici, S.
A1 - Gajdus, M.
A1 - Gallant, Y. A.
A1 - Garrigoux, T.
A1 - Giavitto, G.
A1 - Giebels, B.
A1 - Glicenstein, J. F.
A1 - Gottschall, D.
A1 - Goyal, A.
A1 - Grondin, M. -H.
A1 - Hadasch, D.
A1 - Hahn, J.
A1 - Haupt, M.
A1 - Hawkes, J.
A1 - Heinzelmann, G.
A1 - Henri, G.
A1 - Hermann, G.
A1 - Hervet, O.
A1 - Hillert, A.
A1 - Hinton, J. A.
A1 - Hofmann, W.
A1 - Hoischen, Clemens
A1 - Holler, M.
A1 - Horns, D.
A1 - Ivascenko, A.
A1 - Jacholkowska, A.
A1 - Jamrozy, M.
A1 - Janiak, M.
A1 - Jankowsky, D.
A1 - Jankowsky, F.
A1 - Jingo, M.
A1 - Jogler, T.
A1 - Jouvin, L.
A1 - Jung-Richardt, I.
A1 - Kastendieck, M. A.
A1 - Katarzynski, K.
A1 - Katz, U.
A1 - Kerszberg, D.
A1 - Khelifi, B.
A1 - Kieffer, M.
A1 - King, J.
A1 - Klepser, S.
A1 - Klochkov, D.
A1 - Kluzniak, W.
A1 - Kolitzus, D.
A1 - Komin, Nu.
A1 - Kosack, K.
A1 - Krakau, S.
A1 - Kraus, M.
A1 - Krayzel, F.
A1 - Krueger, P. P.
A1 - Laffon, H.
A1 - Lamanna, G.
A1 - Lau, J.
A1 - Lees, J. -P.
A1 - Lefaucheur, J.
A1 - Lefranc, V.
A1 - Lemiere, A.
A1 - Lemoine-Goumard, M.
A1 - Lenain, J. -P.
A1 - Leser, Eva
A1 - Lohse, T.
A1 - Lorentz, M.
A1 - Liu, R.
A1 - Lopez-Coto, R.
A1 - Lypova, I.
A1 - Marandon, V.
A1 - Marcowith, Alexandre
A1 - Mariaud, C.
A1 - Marx, R.
A1 - Maurin, G.
A1 - Maxted, N.
A1 - Mayer, M.
A1 - Meintjes, P. J.
A1 - Meyer, M.
A1 - Mitchell, A. M. W.
A1 - Moderski, R.
A1 - Mohamed, M.
A1 - Mohrmann, L.
A1 - Mora, K.
A1 - Moulin, Emmanuel
A1 - Murach, T.
A1 - de Naurois, M.
A1 - Niederwanger, F.
A1 - Niemiec, J.
A1 - Oakes, L.
A1 - Odaka, H.
A1 - Oettl, S.
A1 - Ohm, S.
A1 - Wilhelmi, E. de Ona
A1 - Ostrowski, M.
A1 - Oya, I.
A1 - Padovani, M.
A1 - Panter, M.
A1 - Parsons, R. D.
A1 - Arribas, M. Paz
A1 - Pekeur, N. W.
A1 - Pelletier, G.
A1 - Perennes, C.
A1 - Petrucci, P. -O.
A1 - Peyaud, B.
A1 - Pita, S.
A1 - Poon, H.
A1 - Prokhorov, D.
A1 - Prokoph, H.
A1 - Puehlhofer, G.
A1 - Punch, M.
A1 - Quirrenbach, A.
A1 - Raab, S.
A1 - Reimer, A.
A1 - Reimer, O.
A1 - Renaud, M.
A1 - de los Reyes, R.
A1 - Rieger, F.
A1 - Romoli, C.
A1 - Rosier-Lees, S.
A1 - Rowell, G.
A1 - Rudak, B.
A1 - Rulten, C. B.
A1 - Sahakian, V.
A1 - Salek, D.
A1 - Sanchez, D. A.
A1 - Santangelo, Andrea
A1 - Sasaki, M.
A1 - Schlickeiser, R.
A1 - Schuessler, F.
A1 - Schulz, A.
A1 - Schwanke, U.
A1 - Schwemmer, S.
A1 - Settimo, M.
A1 - Seyffert, A. S.
A1 - Shafi, N.
A1 - Shilon, I.
A1 - Simoni, R.
A1 - Sol, H.
A1 - Spanier, F.
A1 - Spengler, G.
A1 - Spies, F.
A1 - Stawarz, L.
A1 - Steenkamp, R.
A1 - Stegmann, Christian
A1 - Stinzing, F.
A1 - Stycz, K.
A1 - Sushch, I.
A1 - Tavernet, J. -P.
A1 - Tavernier, T.
A1 - Taylor, A. M.
A1 - Terrier, R.
A1 - Tibaldo, L.
A1 - Tiziani, D.
A1 - Tluczykont, M.
A1 - Trichard, C.
A1 - Tuffs, R.
A1 - Uchiyama, Y.
A1 - Valerius, K.
A1 - van der Walt, D. J.
A1 - van Eldik, C.
A1 - van Soelen, B.
A1 - Vasileiadis, G.
A1 - Veh, J.
A1 - Venter, C.
A1 - Viana, A.
A1 - Vincent, P.
A1 - Vink, J.
A1 - Voisin, F.
A1 - Voelk, H. J.
A1 - Vuillaume, T.
A1 - Wadiasingh, Z.
A1 - Wagner, S. J.
A1 - Wagner, P.
A1 - Wagner, R. M.
A1 - White, R.
A1 - Wierzcholska, A.
A1 - Willmann, P.
A1 - Woernlein, A.
A1 - Wouters, D.
A1 - Yang, R.
A1 - Zabalza, V.
A1 - Zaborov, D.
A1 - Zacharias, M.
A1 - Zdziarski, A. A.
A1 - Zech, Alraune
A1 - Zefi, F.
A1 - Ziegler, A.
A1 - Zywucka, N.
T1 - The population of TeV pulsar wind nebulae in the HESS Galactic Plane Survey
JF - Astronomy and astrophysics : an international weekly journal
N2 - The nine-year H.E.S.S. Galactic Plane Survey (HGPS) has yielded the most uniform observation scan of the inner Milky Way in the TeV gamma-ray band to date. The sky maps and source catalogue of the HGPS allow for a systematic study of the population of TeV pulsar wind nebulae found throughout the last decade. To investigate the nature and evolution of pulsar wind nebulae, for the first time we also present several upper limits for regions around pulsars without a detected TeV wind nebula. Our data exhibit a correlation of TeV surface brightness with pulsar spindown power (E) over dot. This seems to be caused both by an increase of extension with decreasing (E) over dot, and hence with time, compatible with a power law R-PWN((E) over dot) similar to(E) over dot(0.65 +/- 0.20), and by a mild decrease of TeV gamma-ray luminosity with decreasing (E) over dot, compatible with L-1 (10 TeV) similar to (E) over dot(0.59 +/- 0.21). We also find that the off sets of pulsars with respect to the wind nebula centre with ages around 10 kyr are frequently larger than can be plausibly explained by pulsar proper motion and could be due to an asymmetric environment. In the present data, it seems that a large pulsar off set is correlated with a high apparent TeV efficiency L1- 10 TeV / (E) over dot. In addition to 14 HGPS sources considered firmly identified pulsar wind nebulae and 5 additional pulsar wind nebulae taken from literature, we find 10 HGPS sources that are likely TeV pulsar wind nebula candidates. Using a model that subsumes the present common understanding of the very high-energy radiative evolution of pulsar wind nebulae, we find that the trends and variations of the TeV observables and limits can be reproduced to a good level, drawing a consistent picture of present-day TeV data and theory.
KW - gamma rays: general
KW - catalogs
KW - surveys
KW - ISM: supernova remnants
KW - pulsars: general
Y1 - 2018
U6 - https://doi.org/10.1051/0004-6361/201629377
SN - 1432-0746
VL - 612
PB - EDP Sciences
CY - Les Ulis
ER -
TY - JOUR
A1 - Abdalla, Hassan E.
A1 - Aharonian, Felix A.
A1 - Benkhali, F. Ait
A1 - Angüner, Ekrem Oǧuzhan
A1 - Arakawa, M.
A1 - Arcaro, C.
A1 - Armand, C.
A1 - Arrieta, M.
A1 - Backes, M.
A1 - Barnard, M.
A1 - Becherini, Y.
A1 - Tjus, J. Becker
A1 - Berge, D.
A1 - Bernloehr, K.
A1 - Blackwell, R.
A1 - Bottcher, M.
A1 - Boisson, C.
A1 - Bolmont, J.
A1 - Bonnefoy, S.
A1 - Bordas, Pol
A1 - Bregeon, J.
A1 - Brun, F.
A1 - Brun, P.
A1 - Bryan, M.
A1 - Buechele, M.
A1 - Bulik, T.
A1 - Bylund, T.
A1 - Capasso, M.
A1 - Caroff, S.
A1 - Carosi, A.
A1 - Casanova, Sabrina
A1 - Cerruti, M.
A1 - Chakraborty, N.
A1 - Chand, T.
A1 - Chandra, S.
A1 - Chaves, R. C. G.
A1 - Chen, A.
A1 - Colafrancesco, S.
A1 - Condon, B.
A1 - Davids, I. D.
A1 - Deil, C.
A1 - Devin, J.
A1 - deWilt, P.
A1 - Dirson, L.
A1 - Djannati-Atai, A.
A1 - Dmytriiev, A.
A1 - Donath, A.
A1 - Doroshenko, V
A1 - Dyks, J.
A1 - Egberts, Kathrin
A1 - Emery, G.
A1 - Ernenwein, J-P
A1 - Eschbach, S.
A1 - Fegan, S.
A1 - Fiasson, A.
A1 - Fontaine, G.
A1 - Funk, S.
A1 - Fuessling, M.
A1 - Gabici, S.
A1 - Gallant, Y. A.
A1 - Gate, F.
A1 - Giavitto, G.
A1 - Glawion, D.
A1 - Glicenstein, J. F.
A1 - Gottschall, D.
A1 - Grondin, M-H
A1 - Hahn, J.
A1 - Haupt, M.
A1 - Heinzelmann, G.
A1 - Henri, G.
A1 - Hermann, G.
A1 - Hinton, James Anthony
A1 - Hofmann, W.
A1 - Hoischen, Clemens
A1 - Holch, Tim Lukas
A1 - Holler, M.
A1 - Horns, D.
A1 - Huber, D.
A1 - Iwasaki, H.
A1 - Jacholkowska, A.
A1 - Jamrozy, M.
A1 - Jankowsky, D.
A1 - Jankowsky, F.
A1 - Jouvin, L.
A1 - Jung-Richardt, I
A1 - Kastendieck, M. A.
A1 - Katarzynski, K.
A1 - Katsuragawa, M.
A1 - Katz, U.
A1 - Kerszberg, D.
A1 - Khangulyan, D.
A1 - Khelifi, B.
A1 - King, J.
A1 - Klepser, S.
A1 - Kluzniak, W.
A1 - Komin, Nu
A1 - Kosack, K.
A1 - Kraus, M.
A1 - Lamanna, G.
A1 - Lau, J.
A1 - Lefaucheur, J.
A1 - Lemiere, A.
A1 - Lemoine-Goumard, M.
A1 - Lenain, J-P
A1 - Leser, Eva
A1 - Lohse, T.
A1 - Lopez-Coto, R.
A1 - Lypova, I
A1 - Malyshev, D.
A1 - Marandon, V
A1 - Marcowith, Alexandre
A1 - Mariaud, C.
A1 - Marti-Devesa, G.
A1 - Marx, R.
A1 - Maurin, G.
A1 - Meintjes, P. J.
A1 - Mitchell, A. M. W.
A1 - Moderski, R.
A1 - Mohamed, M.
A1 - Mohrmann, L.
A1 - Moore, C.
A1 - Moulin, Emmanuel
A1 - Murach, T.
A1 - Nakashima, S.
A1 - de Naurois, M.
A1 - Ndiyavala, H.
A1 - Niederwanger, F.
A1 - Niemiec, J.
A1 - Oakes, L.
A1 - Odaka, H.
A1 - Ohm, S.
A1 - Ostrowski, M.
A1 - Oya, I
A1 - Panter, M.
A1 - Parsons, R. D.
A1 - Perennes, C.
A1 - Petrucci, P-O
A1 - Peyaud, B.
A1 - Piel, Q.
A1 - Pita, S.
A1 - Poireau, V
A1 - Noel, A. Priyana
A1 - Prokhorov, D. A.
A1 - Prokoph, H.
A1 - Puehlhofer, G.
A1 - Punch, M.
A1 - Quirrenbach, A.
A1 - Raab, S.
A1 - Rauth, R.
A1 - Reimer, A.
A1 - Reimer, O.
A1 - Renaud, M.
A1 - Rieger, F.
A1 - Rinchiuso, L.
A1 - Romoli, C.
A1 - Rowell, G.
A1 - Rudak, B.
A1 - Ruiz-Velasco, E.
A1 - Sahakian, V
A1 - Saito, S.
A1 - Sanchez, David M.
A1 - Santangelo, Andrea
A1 - Sasaki, M.
A1 - Schlickeiser, R.
A1 - Schussler, F.
A1 - Schulz, A.
A1 - Schutte, H.
A1 - Schwanke, U.
A1 - Schwemmer, S.
A1 - Seglar-Arroyo, M.
A1 - Senniappan, M.
A1 - Seyffert, A. S.
A1 - Shafi, N.
A1 - Shilon, I
A1 - Shiningayamwe, K.
A1 - Simoni, R.
A1 - Sinha, A.
A1 - Sol, H.
A1 - Specovius, A.
A1 - Spir-Jacob, M.
A1 - Stawarz, L.
A1 - Steenkamp, R.
A1 - Stegmann, Christian
A1 - Steppa, Constantin Beverly
A1 - Takahashi, T.
A1 - Tavernet, J-P
A1 - Tavernier, T.
A1 - Taylor, A. M.
A1 - Terrier, R.
A1 - Tibaldo, L.
A1 - Tiziani, D.
A1 - Tluczykont, M.
A1 - Trichard, C.
A1 - Tsirou, M.
A1 - Tsuji, N.
A1 - Tuffs, R.
A1 - Uchiyama, Y.
A1 - van der Walt, D. J.
A1 - van Eldik, C.
A1 - van Rensburg, C.
A1 - van Soelen, B.
A1 - Vasileiadis, G.
A1 - Veh, J.
A1 - Venter, C.
A1 - Vincent, P.
A1 - Vink, J.
A1 - Voisin, F.
A1 - Voelk, H. J.
A1 - Vuillaume, T.
A1 - Wadiasingh, Z.
A1 - Wagner, S. J.
A1 - Wagner, R. M.
A1 - White, R.
A1 - Wierzcholska, A.
A1 - Yang, R.
A1 - Yoneda, H.
A1 - Zaborov, D.
A1 - Zacharias, M.
A1 - Zanin, R.
A1 - Zdziarski, A. A.
A1 - Zech, Alraune
A1 - Zefi, F.
A1 - Ziegler, A.
A1 - Zorn, J.
A1 - Zywucka, N.
T1 - Particle transport within the pulsar wind nebula HESS J1825-137
JF - Astronomy and astrophysics : an international weekly journal
N2 - Context. We present a detailed view of the pulsar wind nebula (PWN) HESS J1825-137. We aim to constrain the mechanisms dominating the particle transport within the nebula, accounting for its anomalously large size and spectral characteristics. Aims. The nebula was studied using a deep exposure from over 12 years of H.E.S.S. I operation, together with data from H.E.S.S. II that improve the low-energy sensitivity. Enhanced energy-dependent morphological and spatially resolved spectral analyses probe the very high energy (VHE, E > 0.1 TeV) gamma-ray properties of the nebula. Methods. The nebula emission is revealed to extend out to 1.5 degrees from the pulsar, similar to 1.5 times farther than previously seen, making HESS J1825-137, with an intrinsic diameter of similar to 100 pc, potentially the largest gamma-ray PWN currently known. Characterising the strongly energy-dependent morphology of the nebula enables us to constrain the particle transport mechanisms. A dependence of the nebula extent with energy of R proportional to E alpha with alpha = -0.29 +/- 0.04(stat) +/- 0.05(sys) disfavours a pure diffusion scenario for particle transport within the nebula. The total gamma-ray flux of the nebula above 1 TeV is found to be (1.12 +/- 0.03(stat) +/- 0.25(sys)) +/- 10(-11) cm(-2) s(-1), corresponding to similar to 64% of the flux of the Crab nebula. Results. HESS J1825-137 is a PWN with clearly energy-dependent morphology at VHE gamma-ray energies. This source is used as a laboratory to investigate particle transport within intermediate-age PWNe. Based on deep observations of this highly spatially extended PWN, we produce a spectral map of the region that provides insights into the spectral variation within the nebula.
KW - gamma rays: general
KW - acceleration of particles
KW - convection
KW - diffusion
KW - pulsars: general
Y1 - 2019
U6 - https://doi.org/10.1051/0004-6361/201834335
SN - 1432-0746
VL - 621
PB - EDP Sciences
CY - Les Ulis
ER -
TY - JOUR
A1 - Abramowski, A.
A1 - Aharonian, Felix A.
A1 - Benkhali, F. Ait
A1 - Akhperjanian, A. G.
A1 - Anguener, E. O.
A1 - Backes, M.
A1 - Balzer, A.
A1 - Becherini, Y.
A1 - Tjus, J. Becker
A1 - Berge, D.
A1 - Bernhard, S.
A1 - Bernloehr, K.
A1 - Birsin, E.
A1 - Blackwell, R.
A1 - Boettcher, M.
A1 - Boisson, C.
A1 - Bolmont, J.
A1 - Bordas, Pol
A1 - Bregeon, J.
A1 - Brun, F.
A1 - Brun, P.
A1 - Bryan, M.
A1 - Bulik, T.
A1 - Carr, J.
A1 - Casanova, Sabrina
A1 - Chakraborty, N.
A1 - Chalme-Calvet, R.
A1 - Chaves, R. C. G.
A1 - Chen, A.
A1 - Chevalier, J.
A1 - Chretien, M.
A1 - Colafrancesco, S.
A1 - Cologna, G.
A1 - Condon, B.
A1 - Conrad, J.
A1 - Couturier, C.
A1 - Cui, Y.
A1 - Davids, I. D.
A1 - Degrange, B.
A1 - Deil, C.
A1 - deWilt, P.
A1 - Djannati-Atai, A.
A1 - Domainko, W.
A1 - Donath, A.
A1 - Dubus, G.
A1 - Dutson, K.
A1 - Dyks, J.
A1 - Dyrda, M.
A1 - Edwards, T.
A1 - Egberts, Kathrin
A1 - Eger, P.
A1 - Ernenwein, J. -P.
A1 - Espigat, P.
A1 - Farnier, C.
A1 - Fegan, S.
A1 - Feinstein, F.
A1 - Fernandes, M. V.
A1 - Fernandez, D.
A1 - Fiasson, A.
A1 - Fontaine, G.
A1 - Foerster, A.
A1 - Fuessling, M.
A1 - Gabici, S.
A1 - Gajdus, M.
A1 - Gallant, Y. A.
A1 - Garrigoux, T.
A1 - Giavitto, G.
A1 - Giebels, B.
A1 - Glicenstein, J. F.
A1 - Gottschall, D.
A1 - Goyal, A.
A1 - Grondin, M. -H.
A1 - Grudzinska, M.
A1 - Hadasch, D.
A1 - Haeffner, S.
A1 - Hahn, J.
A1 - Hawkes, J.
A1 - Heinzelmann, G.
A1 - Henri, G.
A1 - Hermann, G.
A1 - Hervet, O.
A1 - Hillert, A.
A1 - Hinton, J. A.
A1 - Hofmann, W.
A1 - Hofverberg, P.
A1 - Hoischen, Clemens
A1 - Holler, M.
A1 - Horns, D.
A1 - Ivascenko, A.
A1 - Jacholkowska, A.
A1 - Jamrozy, M.
A1 - Janiak, M.
A1 - Jankowsky, F.
A1 - Jung-Richardt, I.
A1 - Kastendieck, M. A.
A1 - Katarzynski, K.
A1 - Katz, U.
A1 - Kerszberg, D.
A1 - Khelifi, B.
A1 - Kieffer, M.
A1 - Klepser, S.
A1 - Klochkov, D.
A1 - Kluzniak, W.
A1 - Kolitzus, D.
A1 - Komin, Nu.
A1 - Kosack, K.
A1 - Krakau, S.
A1 - Krayzel, F.
A1 - Krueger, P. P.
A1 - Laffon, H.
A1 - Lamanna, G.
A1 - Lau, J.
A1 - Lefaucheur, J.
A1 - Lefranc, V.
A1 - Lemiere, A.
A1 - Lemoine-Goumard, M.
A1 - Lenain, J. -P.
A1 - Lohse, T.
A1 - Lopatin, A.
A1 - Lorentz, M.
A1 - Lu, C. -C.
A1 - Lui, R.
A1 - Marandon, V.
A1 - Marcowith, Alexandre
A1 - Mariaud, C.
A1 - Marx, R.
A1 - Maurin, G.
A1 - Maxted, N.
A1 - Mayer, M.
A1 - Meintjes, P. J.
A1 - Menzler, U.
A1 - Meyer, M.
A1 - Mitchell, A. M. W.
A1 - Moderski, R.
A1 - Mohamed, M.
A1 - Mora, K.
A1 - Moulin, Emmanuel
A1 - Murach, T.
A1 - de Naurois, M.
A1 - Niemiec, J.
A1 - Oakes, L.
A1 - Odaka, H.
A1 - Oettl, S.
A1 - Ohm, S.
A1 - Opitz, B.
A1 - Ostrowski, M.
A1 - Oya, I.
A1 - Panter, M.
A1 - Parsons, R. D.
A1 - Arribas, M. Paz
A1 - Pekeur, N. W.
A1 - Pelletier, G.
A1 - Petrucci, P. -O.
A1 - Peyaud, B.
A1 - Pita, S.
A1 - Poon, H.
A1 - Prokhorov, D.
A1 - Prokoph, H.
A1 - Puehlhofer, G.
A1 - Punch, M.
A1 - Quirrenbach, A.
A1 - Raab, S.
A1 - Reichardt, I.
A1 - Reimer, A.
A1 - Reimer, O.
A1 - Renaud, M.
A1 - de los Reyes, R.
A1 - Rieger, F.
A1 - Romoli, C.
A1 - Rosier-Lees, S.
A1 - Rowell, G.
A1 - Rudak, B.
A1 - Rulten, C. B.
A1 - Sahakian, V.
A1 - Salek, D.
A1 - Sanchez, D. A.
A1 - Santangelo, Andrea
A1 - Sasaki, M.
A1 - Schlickeiser, R.
A1 - Schuessler, F.
A1 - Schulz, A.
A1 - Schwanke, U.
A1 - Schwemmer, S.
A1 - Seyffert, A. S.
A1 - Simoni, R.
A1 - Sol, H.
A1 - Spanier, F.
A1 - Spengler, G.
A1 - Spies, F.
A1 - Stawarz, L.
A1 - Steenkamp, R.
A1 - Stegmann, Christian
A1 - Stinzing, F.
A1 - Stycz, K.
A1 - Sushch, I.
A1 - Tavernet, J. -P.
A1 - Tavernier, T.
A1 - Taylor, A. M.
A1 - Terrier, R.
A1 - Tluczykont, M.
A1 - Trichard, C.
A1 - Tuffs, R.
A1 - Valerius, K.
A1 - van der Walt, J.
A1 - van Eldik, C.
A1 - van Soelen, B.
A1 - Vasileiadis, G.
A1 - Veh, J.
A1 - Venter, C.
A1 - Viana, A.
A1 - Vincent, P.
A1 - Vink, J.
A1 - Voisin, F.
A1 - Voelk, H. J.
A1 - Vuillaume, T.
A1 - Wagner, S. J.
A1 - Wagner, P.
A1 - Wagner, R. M.
A1 - Weidinger, M.
A1 - White, R.
A1 - Wierzcholska, A.
A1 - Willmann, P.
A1 - Woernlein, A.
A1 - Wouters, D.
A1 - Yang, R.
A1 - Zabalza, V.
A1 - Zaborov, D.
A1 - Zacharias, M.
A1 - Zdziarski, A. A.
A1 - Zech, Alraune
A1 - Zefi, F.
A1 - Zywucka, N.
T1 - Detailed spectral and morphological analysis of the shell type supernova remnant RCW 86
JF - Astronomy and astrophysics : an international weekly journal
N2 - Aims. We aim for an understanding of the morphological and spectral properties of the supernova remnant RCW 86 and for insights into the production mechanism leading to the RCW 86 very high-energy gamma-ray emission. Methods. We analyzed High Energy Spectroscopic System (H.E.S.S.) data that had increased sensitivity compared to the observations presented in the RCW 86 H.E.S.S. discovery publication. Studies of the morphological correlation between the 0.5-1 keV X-ray band, the 2-5 keV X-ray band, radio, and gamma-ray emissions have been performed as well as broadband modeling of the spectral energy distribution with two different emission models. Results. We present the first conclusive evidence that the TeV gamma-ray emission region is shell-like based on our morphological studies. The comparison with 2-5 keV X-ray data reveals a correlation with the 0.4-50 TeV gamma-ray emission. The spectrum of RCW 86 is best described by a power law with an exponential cutoff at E-cut = (3.5 +/- 1.2(stat)) TeV and a spectral index of Gamma approximate to 1.6 +/- 0.2. A static leptonic one-zone model adequately describes the measured spectral energy distribution of RCW 86, with the resultant total kinetic energy of the electrons above 1 GeV being equivalent to similar to 0.1% of the initial kinetic energy of a Type Ia supernova explosion (10(51) erg). When using a hadronic model, a magnetic field of B approximate to 100 mu G is needed to represent the measured data. Although this is comparable to formerly published estimates, a standard E-2 spectrum for the proton distribution cannot describe the gamma-ray data. Instead, a spectral index of Gamma(p) approximate to 1.7 would be required, which implies that similar to 7 x 10(49)/n(cm-3) erg has been transferred into high-energy protons with the effective density n(cm-3) = n/1 cm(-3). This is about 10% of the kinetic energy of a typical Type Ia supernova under the assumption of a density of 1 cm(-3).
KW - astroparticle physics
KW - gamma rays: general
KW - ISM: supernova remnants
KW - cosmic rays
Y1 - 2018
U6 - https://doi.org/10.1051/0004-6361/201526545
SN - 1432-0746
VL - 612
PB - EDP Sciences
CY - Les Ulis
ER -
TY - JOUR
A1 - Abdalla, Hassan E.
A1 - Abramowski, A.
A1 - Aharonian, Felix A.
A1 - Benkhali, F. Ait
A1 - Akhperjanian, A. G.
A1 - Andersson, T.
A1 - Anguener, O.
A1 - Arrieta, M.
A1 - Aubert, P.
A1 - Backes, M.
A1 - Balzer, A.
A1 - Barnard, M.
A1 - Becherini, Y.
A1 - Tjus, J. Becker
A1 - Berge, D.
A1 - Bernhard, S.
A1 - Bernloehr, K.
A1 - Blackwell, R.
A1 - Boettcher, M.
A1 - Boisson, C.
A1 - Bolmont, J.
A1 - Bordas, Pol
A1 - Bregeon, J.
A1 - Brun, F.
A1 - Brun, P.
A1 - Bryan, M.
A1 - Bulik, T.
A1 - Capasso, M.
A1 - Carr, J.
A1 - Casanova, Sabrina
A1 - Cerruti, M.
A1 - Chakraborty, N.
A1 - Chalme-Calvet, R.
A1 - Chaves, R. C. G.
A1 - Chen, A.
A1 - Chevalier, J.
A1 - Chretien, M.
A1 - Colafrancesco, S.
A1 - Cologna, G.
A1 - Condon, B.
A1 - Conrad, J.
A1 - Cui, Y.
A1 - Davids, I. D.
A1 - Decock, J.
A1 - Degrange, B.
A1 - Deil, C.
A1 - Devin, J.
A1 - deWilt, P.
A1 - Dirson, L.
A1 - Djannati-Atai, A.
A1 - Domainko, W.
A1 - Donath, A.
A1 - Dubus, G.
A1 - Dutson, K.
A1 - Dyks, J.
A1 - Edwards, T.
A1 - Egberts, Kathrin
A1 - Eger, P.
A1 - Ernenwein, J. -P.
A1 - Eschbach, S.
A1 - Farnier, C.
A1 - Fegan, S.
A1 - Fernandes, M. V.
A1 - Fiasson, A.
A1 - Fontaine, G.
A1 - Foerster, A.
A1 - Funk, S.
A1 - Fuessling, M.
A1 - Gabici, S.
A1 - Gajdus, M.
A1 - Gallant, Y. A.
A1 - Garrigoux, T.
A1 - Giavitto, G.
A1 - Giebels, B.
A1 - Glicenstein, J. F.
A1 - Gottschall, D.
A1 - Goyal, A.
A1 - Grondin, M. -H.
A1 - Hadasch, D.
A1 - Hahn, J.
A1 - Haupt, M.
A1 - Hawkes, J.
A1 - Heinzelmann, G.
A1 - Henri, G.
A1 - Hermann, G.
A1 - Hervet, O.
A1 - Hinton, J. A.
A1 - Hofmann, W.
A1 - Hoischen, Clemens
A1 - Holler, M.
A1 - Horns, D.
A1 - Ivascenko, A.
A1 - Jacholkowska, A.
A1 - Jamrozy, M.
A1 - Janiak, M.
A1 - Jankowsky, D.
A1 - Jankowsky, F.
A1 - Jingo, M.
A1 - Jogler, T.
A1 - Jouvin, L.
A1 - Jung-Richardt, I.
A1 - Kastendieck, M. A.
A1 - Katarzynski, K.
A1 - Katz, U.
A1 - Kerszberg, D.
A1 - Khelifi, B.
A1 - Kieffer, M.
A1 - King, J.
A1 - Klepser, S.
A1 - Klochkov, D.
A1 - Kluzniak, W.
A1 - Kolitzus, D.
A1 - Komin, Nu.
A1 - Kosack, K.
A1 - Krakau, S.
A1 - Kraus, M.
A1 - Krayzel, F.
A1 - Krueger, P. P.
A1 - Laffon, H.
A1 - Lamanna, G.
A1 - Lau, J.
A1 - Lees, J. -P.
A1 - Lefaucheur, J.
A1 - Lefranc, V.
A1 - Lemiere, A.
A1 - Lemoine-Goumard, M.
A1 - Lenain, J. -P.
A1 - Leser, Eva
A1 - Lohse, T.
A1 - Lorentz, M.
A1 - Liu, R.
A1 - Lopez-Coto, R.
A1 - Lypova, I.
A1 - Marandon, V.
A1 - Marcowith, Alexandre
A1 - Mariaud, C.
A1 - Marx, R.
A1 - Maurin, G.
A1 - Maxted, N.
A1 - Mayer, M.
A1 - Meintjes, P. J.
A1 - Meyer, M.
A1 - Mitchell, A. M. W.
A1 - Moderski, R.
A1 - Mohamed, M.
A1 - Mohrmann, L.
A1 - Mora, K.
A1 - Moulin, Emmanuel
A1 - Murach, T.
A1 - de Naurois, M.
A1 - Niederwanger, F.
A1 - Niemiec, J.
A1 - Oakes, L.
A1 - Odaka, H.
A1 - Oettl, S.
A1 - Ohm, S.
A1 - Ostrowski, M.
A1 - Oya, I.
A1 - Padovani, M.
A1 - Panter, M.
A1 - Parsons, R. D.
A1 - Pekeur, N. W.
A1 - Pelletier, G.
A1 - Perennes, C.
A1 - Petrucci, P. -O.
A1 - Peyaud, B.
A1 - Piel, Q.
A1 - Pita, S.
A1 - Poon, H.
A1 - Prokhorov, D.
A1 - Prokoph, H.
A1 - Puehlhofer, G.
A1 - Punch, M.
A1 - Quirrenbach, A.
A1 - Raab, S.
A1 - Reimer, A.
A1 - Reimer, O.
A1 - Renaud, M.
A1 - de los Reyes, R.
A1 - Rieger, F.
A1 - Romoli, C.
A1 - Rosier-Lees, S.
A1 - Rowell, G.
A1 - Rudak, B.
A1 - Rulten, C. B.
A1 - Sahakian, V.
A1 - Salek, D.
A1 - Sanchez, D. A.
A1 - Santangelo, Andrea
A1 - Sasaki, M.
A1 - Schlickeiser, R.
A1 - Schuessler, F.
A1 - Schulz, A.
A1 - Schwanke, U.
A1 - Schwemmer, S.
A1 - Settimo, M.
A1 - Seyffert, A. S.
A1 - Shafi, N.
A1 - Shilon, I.
A1 - Simoni, R.
A1 - Sol, H.
A1 - Spanier, F.
A1 - Spengler, G.
A1 - Spies, F.
A1 - Stawarz, L.
A1 - Steenkamp, R.
A1 - Stegmann, Christian
A1 - Stinzing, F.
A1 - Stycz, K.
A1 - Sushch, I.
A1 - Tavernet, J. -P.
A1 - Tavernier, T.
A1 - Taylor, A. M.
A1 - Terrier, R.
A1 - Tibaldo, L.
A1 - Tiziani, D.
A1 - Tluczykont, M.
A1 - Trichard, C.
A1 - Tuffs, R.
A1 - Uchiyama, Y.
A1 - van der Walt, D. J.
A1 - van Eldik, C.
A1 - van Rensburg, C.
A1 - van Soelen, B.
A1 - Vasileiadis, G.
A1 - Veh, J.
A1 - Venter, C.
A1 - Viana, A.
A1 - Vincent, P.
A1 - Vink, J.
A1 - Voisin, F.
A1 - Voelk, H. J.
A1 - Vuillaume, T.
A1 - Wadiasingh, Z.
A1 - Wagner, S. J.
A1 - Wagner, P.
A1 - Wagner, R. M.
A1 - White, R.
A1 - Wierzcholska, A.
A1 - Willmann, P.
A1 - Woernlein, A.
A1 - Wouters, D.
A1 - Yang, R.
A1 - Zabalza, V.
A1 - Zaborov, D.
A1 - Zacharias, M.
A1 - Zdziarski, A. A.
A1 - Zech, Alraune
A1 - Zefi, F.
A1 - Ziegler, A.
A1 - Zywucka, N.
A1 - Katsuta, J.
T1 - The supernova remnant W49B as seen with HESS and Fermi-LAT
JF - Astronomy and astrophysics : an international weekly journal
N2 - The supernova remnant (SNR) W49B originated from a core-collapse supernova that occurred between one and four thousand years ago, and subsequently evolved into a mixed-morphology remnant, which is interacting with molecular clouds (MC). Gamma-ray observations of SNR-MC associations are a powerful tool to constrain the origin of Galactic cosmic rays, as they can probe the acceleration of hadrons through their interaction with the surrounding medium and subsequent emission of non-thermal photons. We report the detection of a gamma-ray source coincident with W49B at very high energies (VHE; E > 100 GeV) with the H.E.S.S. Cherenkov telescopes together with a study of the source with five years of Fermi-LAT high-energy gamma-ray (0.06-300 GeV) data. The smoothly connected, combined source spectrum, measured from 60 MeV to multi-TeV energies, shows two significant spectral breaks at 304 +/- 20 MeV and 8.4(-2.5)(+2.5) GeV; the latter is constrained by the joint fit from the two instruments. The detected spectral features are similar to those observed in several other SNR-MC associations and are found to be indicative of gamma-ray emission produced through neutral-pion decay.
KW - gamma rays: general
KW - ISM: supernova remnants
KW - ISM: clouds
Y1 - 2018
U6 - https://doi.org/10.1051/0004-6361/201527843
SN - 1432-0746
VL - 612
PB - EDP Sciences
CY - Les Ulis
ER -
TY - JOUR
A1 - Abdalla, Hassan E.
A1 - Abramowski, A.
A1 - Aharonian, Felix A.
A1 - Benkhali, F. Ait
A1 - Akhperjanian, A. G.
A1 - Andersson, T.
A1 - Anguener, E. O.
A1 - Arakawa, M.
A1 - Arrieta, M.
A1 - Aubert, P.
A1 - Backes, M.
A1 - Balzer, A.
A1 - Barnard, M.
A1 - Becherini, Y.
A1 - Tjus, J. Becker
A1 - Berge, D.
A1 - Bernhard, S.
A1 - Bernloehr, K.
A1 - Blackwell, R.
A1 - Boettcher, M.
A1 - Boisson, C.
A1 - Bolmont, J.
A1 - Bordas, Pol
A1 - Bregeon, J.
A1 - Brun, F.
A1 - Brun, P.
A1 - Bryan, M.
A1 - Bilchele, M.
A1 - Bulik, T.
A1 - Capasso, M.
A1 - Carr, J.
A1 - Casanova, Sabrina
A1 - Cerruti, M.
A1 - Chakraborty, N.
A1 - Chalme-Calvet, R.
A1 - Chaves, R. C. G.
A1 - Chen, A.
A1 - Chevalier, J.
A1 - Chretien, M.
A1 - Coffaro, M.
A1 - Colafrancesco, S.
A1 - Cologna, G.
A1 - Condon, B.
A1 - Conrad, J.
A1 - Cui, Y.
A1 - Davids, I. D.
A1 - Decock, J.
A1 - Degrange, B.
A1 - Deil, C.
A1 - Devin, J.
A1 - deWilt, P.
A1 - Dirson, L.
A1 - Djannati-Atai, A.
A1 - Domainko, W.
A1 - Donath, A.
A1 - Dutson, K.
A1 - Dyks, J.
A1 - Edwards, T.
A1 - Egberts, Kathrin
A1 - Eger, P.
A1 - Ernenwein, J. -P.
A1 - Eschbach, S.
A1 - Farnier, C.
A1 - Fegan, S.
A1 - Fernandes, M. V.
A1 - Fiasson, A.
A1 - Fontaine, G.
A1 - Foerster, A.
A1 - Funk, S.
A1 - Fuessling, M.
A1 - Gabici, S.
A1 - Gajdus, M.
A1 - Gallant, Y. A.
A1 - Garrigoux, T.
A1 - Giavitto, G.
A1 - Giebels, B.
A1 - Glicenstein, J. F.
A1 - Gottschall, D.
A1 - Goya, A.
A1 - Grondin, M. -H.
A1 - Hahn, J.
A1 - Haupt, M.
A1 - Hawkes, J.
A1 - Heinzelmann, G.
A1 - Henri, G.
A1 - Hermann, G.
A1 - Hervet, O.
A1 - Hinton, J. A.
A1 - Hofmann, W.
A1 - Hoischen, Clemens
A1 - Holler, M.
A1 - Horns, D.
A1 - Ivascenko, A.
A1 - Iwasaki, H.
A1 - Jacholkowska, A.
A1 - Jamrozy, M.
A1 - Janiak, M.
A1 - Jankowsky, D.
A1 - Jankowsky, F.
A1 - Jingo, M.
A1 - Jogler, T.
A1 - Jouvin, L.
A1 - Jung-Richardt, I.
A1 - Kastendieck, M. A.
A1 - Katarzynski, K.
A1 - Katsuragawa, M.
A1 - Katz, U.
A1 - Kerszberg, D.
A1 - Khangulyan, D.
A1 - Khelifi, B.
A1 - Kieffer, M.
A1 - King, J.
A1 - Klepser, S.
A1 - Klochkov, D.
A1 - Kluzniak, W.
A1 - Kolitzus, D.
A1 - Komin, Nu.
A1 - Kosack, K.
A1 - Krakau, S.
A1 - Kraus, M.
A1 - Krueger, P. P.
A1 - Laffon, H.
A1 - Lamanna, G.
A1 - Lau, J.
A1 - Lees, J. -P.
A1 - Lefaucheur, J.
A1 - Lefranc, V.
A1 - Lemiere, A.
A1 - Lemoine-Goumard, M.
A1 - Lenain, J. -P.
A1 - Leser, Eva
A1 - Lohse, T.
A1 - Lorentz, M.
A1 - Liu, R.
A1 - Lopez-Coto, R.
A1 - Lypova, I.
A1 - Marandon, V.
A1 - Marcowith, Alexandre
A1 - Mariaud, C.
A1 - Marx, R.
A1 - Maurin, G.
A1 - Maxted, N.
A1 - Mayer, M.
A1 - Meintjes, P. J.
A1 - Meyer, M.
A1 - Mitche, A. M. W.
A1 - Moderski, R.
A1 - Mohamed, M.
A1 - Mohrmann, L.
A1 - Mora, K.
A1 - Moulin, Emmanuel
A1 - Murach, T.
A1 - Nakashima, S.
A1 - de Naurois, M.
A1 - Niederwanger, F.
A1 - Niemiec, J.
A1 - Oakes, L.
A1 - Odaka, H.
A1 - Oettl, S.
A1 - Ohm, S.
A1 - Ostrowski, M.
A1 - Oya, I.
A1 - Padovani, M.
A1 - Panter, M.
A1 - Parsons, R. D.
A1 - Arribas, M. Paz
A1 - Pekeur, N. W.
A1 - Pelletier, G.
A1 - Perennes, C.
A1 - Petrucci, P. -O.
A1 - Peyaud, B.
A1 - Piel, Q.
A1 - Pita, S.
A1 - Poon, H.
A1 - Prokhorov, D.
A1 - Prokoph, H.
A1 - Puehlhofer, G.
A1 - Punch, M.
A1 - Quirrenbach, A.
A1 - Raab, S.
A1 - Reimer, A.
A1 - Reimer, O.
A1 - Renaud, M.
A1 - de los Reyes, R.
A1 - Richter, S.
A1 - Rieger, F.
A1 - Romoli, C.
A1 - Rowell, G.
A1 - Rudak, B.
A1 - Rulten, C. B.
A1 - Sahakian, V.
A1 - Saito, S.
A1 - Salek, D.
A1 - Sanchez, D. A.
A1 - Santangelo, Andrea
A1 - Sasaki, M.
A1 - Schlickeiser, R.
A1 - Schuessler, F.
A1 - Schulz, A.
A1 - Schwanke, U.
A1 - Schwemmer, S.
A1 - Seglar-Arroyo, M.
A1 - Settimo, M.
A1 - Seyffert, A. S.
A1 - Shafi, N.
A1 - Shilon, I.
A1 - Simoni, R.
A1 - Sol, H.
A1 - Spanier, F.
A1 - Spengler, G.
A1 - Spies, F.
A1 - Stawarz, L.
A1 - Steenkamp, R.
A1 - Stegmann, Christian
A1 - Stycz, K.
A1 - Sushch, I.
A1 - Takahashi, T.
A1 - Tavernet, J. -P.
A1 - Tavernier, T.
A1 - Taylor, A. M.
A1 - Terrier, R.
A1 - Tibaldo, L.
A1 - Tiziani, D.
A1 - Tluczykont, M.
A1 - Trichard, C.
A1 - Tsuji, N.
A1 - Tuffs, R.
A1 - Uchiyama, Y.
A1 - van der Walt, D. J.
A1 - van Eldik, C.
A1 - van Rensburg, C.
A1 - van Soelen, B.
A1 - Vasileiadis, G.
A1 - Veh, J.
A1 - Venter, C.
A1 - Viana, A.
A1 - Vincent, P.
A1 - Vink, J.
A1 - Voisin, F.
A1 - Voelk, H. J.
A1 - Vuillaume, T.
A1 - Wadiasingh, Z.
A1 - Wagner, S. J.
A1 - Wagner, P.
A1 - Wagner, R. M.
A1 - White, R.
A1 - Wierzcholska, A.
A1 - Willmann, P.
A1 - Woernlein, A.
A1 - Wouters, D.
A1 - Yang, R.
A1 - Zabalza, V.
A1 - Zaborov, D.
A1 - Zacharias, M.
A1 - Zanin, R.
A1 - Zdziarski, A. A.
A1 - Zech, Alraune
A1 - Zefi, F.
A1 - Ziegler, A.
A1 - Zywucka, N.
T1 - Deeper HESS observations of Vela Junior (RX J0852.0-4622)
BT - Morphology studies and resolved spectroscopy
JF - Astronomy and astrophysics : an international weekly journal
N2 - Aims. We study gamma-ray emission from the shell-type supernova remnant (SNR) RXJ0852.0-4622 to better characterize its spectral properties and its distribution over the SNR. Methods. The analysis of an extended High Energy Spectroscopic System (H.E.S.S.) data set at very high energies (E > 100 GeV) permits detailed studies, as well as spatially resolved spectroscopy, of the morphology and spectrum of the whole RXJ0852.0-4622 region. The H.E.S.S. data are combined with archival data from other wavebands and interpreted in the framework of leptonic and hadronic models. The joint Fermi-LAT-H.E.S.S. spectrum allows the direct determination of the spectral characteristics of the parent particle population in leptonic and hadronic scenarios using only GeV-TeV data. Results. An updated analysis of the H.E.S.S. data shows that the spectrum of the entire SNR connects smoothly to the high-energy spectrum measured by Fermi-LAT. The increased data set makes it possible to demonstrate that the H.E.S.S. spectrum deviates significantly from a power law and is well described by both a curved power law and a power law with an exponential cutoff at an energy of E-cut = (6.7 +/- 1.2(stat) +/- 1.2(syst)) TeV. The joint Fermi-LAT-H.E.S.S. spectrum allows the unambiguous identification of the spectral shape as a power law with an exponential cutoff. No significant evidence is found for a variation of the spectral parameters across the SNR, suggesting similar conditions of particle acceleration across the remnant. A simple modeling using one particle population to model the SNR emission demonstrates that both leptonic and hadronic emission scenarios remain plausible. It is also shown that at least a part of the shell emission is likely due to the presence of a pulsar wind nebula around PSR J0855-4644.
KW - astroparticle physics
KW - gamma rays: general
KW - acceleration of particles
KW - cosmic rays
KW - ISM: supernova remnants
Y1 - 2018
U6 - https://doi.org/10.1051/0004-6361/201630002
SN - 1432-0746
VL - 612
PB - EDP Sciences
CY - Les Ulis
ER -
TY - JOUR
A1 - Abdalla, Hassan E.
A1 - Abramowski, A.
A1 - Aharonian, Felix A.
A1 - Benkhali, F. Ait
A1 - Angüner, Ekrem Oǧuzhan
A1 - Arakawa, M.
A1 - Armand, C.
A1 - Arrieta, M.
A1 - Backes, M.
A1 - Balzer, A.
A1 - Barnard, M.
A1 - Becherini, Y.
A1 - Tjus, J. Becker
A1 - Berge, D.
A1 - Bernhard, S.
A1 - Bernloehr, K.
A1 - Blackwell, R.
A1 - Boettcher, M.
A1 - Boisson, C.
A1 - Bolmont, J.
A1 - Bonnefoy, S.
A1 - Bordas, Pol
A1 - Bregeon, J.
A1 - Brun, F.
A1 - Brun, P.
A1 - Bryan, M.
A1 - Buechele, M.
A1 - Bulik, T.
A1 - Capasso, M.
A1 - Caroff, S.
A1 - Carosi, A.
A1 - Casanova, Sabrina
A1 - Cerruti, M.
A1 - Chakraborty, N.
A1 - Chaves, R. C. G.
A1 - Chen, A.
A1 - Chevalier, J.
A1 - Colafrancesco, S.
A1 - Condon, B.
A1 - Conrad, J.
A1 - Davids, I. D.
A1 - Decock, J.
A1 - Deil, C.
A1 - Devin, J.
A1 - deWilt, P.
A1 - Dirson, L.
A1 - Djannati-Atai, A.
A1 - Donath, A.
A1 - Dyks, J.
A1 - Edwards, T.
A1 - Egberts, Kathrin
A1 - Emery, G.
A1 - Ernenwein, J. -P.
A1 - Eschbach, S.
A1 - Farnier, C.
A1 - Fegan, S.
A1 - Fernandes, M. V.
A1 - Fiasson, A.
A1 - Fontaine, G.
A1 - Funk, S.
A1 - Fuessling, M.
A1 - Gabici, S.
A1 - Gallant, Y. A.
A1 - Garrigoux, T.
A1 - Gate, F.
A1 - Giavitto, G.
A1 - Glawion, D.
A1 - Glicenstein, J. F.
A1 - Gottschall, D.
A1 - Grondin, M. -H.
A1 - Hahn, J.
A1 - Haupt, M.
A1 - Hawkes, J.
A1 - Heinzelmann, G.
A1 - Henri, G.
A1 - Hermann, G.
A1 - Hinton, J. A.
A1 - Hofmann, W.
A1 - Hoischen, Clemens
A1 - Holch, T. L.
A1 - Holler, M.
A1 - Horns, D.
A1 - Ivascenko, A.
A1 - Iwasaki, H.
A1 - Jacholkowska, A.
A1 - Jamrozy, M.
A1 - Jankowsky, D.
A1 - Jankowsky, F.
A1 - Jingo, M.
A1 - Jouvin, L.
A1 - Jung-Richardt, I.
A1 - Kastendieck, M. A.
A1 - Katarzynski, K.
A1 - Katsuragawa, M.
A1 - Katz, U.
A1 - Kerszberg, D.
A1 - Khangulyan, D.
A1 - Khelifi, B.
A1 - King, J.
A1 - Klepser, S.
A1 - Klochkov, D.
A1 - Kluzniak, W.
A1 - Komin, Nu.
A1 - Kosack, K.
A1 - Krakau, S.
A1 - Kraus, M.
A1 - Kruger, P. P.
A1 - Laffon, H.
A1 - Lamanna, G.
A1 - Lau, J.
A1 - Lefaucheur, J.
A1 - Lemiere, A.
A1 - Lemoine-Goumard, M.
A1 - Lenain, J. -P.
A1 - Leser, Eva
A1 - Lohse, T.
A1 - Lorentz, M.
A1 - Liu, R.
A1 - Lopez-Coto, R.
A1 - Lypova, I.
A1 - Malyshev, D.
A1 - Marandon, V.
A1 - Marcowith, Alexandre
A1 - Mariaud, C.
A1 - Marx, R.
A1 - Maurin, G.
A1 - Maxted, N.
A1 - Mayer, M.
A1 - Meintjes, P. J.
A1 - Meyer, M.
A1 - Mitchell, A. M. W.
A1 - Moderski, R.
A1 - Mohamed, M.
A1 - Mohrmann, L.
A1 - Mora, K.
A1 - Moulin, Emmanuel
A1 - Murach, T.
A1 - Nakashima, S.
A1 - de Naurois, M.
A1 - Ndiyavala, H.
A1 - Niederwanger, F.
A1 - Niemiec, J.
A1 - Oakes, L.
A1 - Odaka, H.
A1 - Ohm, S.
A1 - Ostrowski, M.
A1 - Oya, I.
A1 - Padovani, M.
A1 - Panter, M.
A1 - Parsons, R. D.
A1 - Pekeur, N. W.
A1 - Pelletier, G.
A1 - Perennes, C.
A1 - Petrucci, P. -O.
A1 - Peyaud, B.
A1 - Piel, Q.
A1 - Pita, S.
A1 - Poireau, V.
A1 - Prokhorov, D. A.
A1 - Prokoph, H.
A1 - Puehlhofer, G.
A1 - Punch, M.
A1 - Quirrenbach, A.
A1 - Raab, S.
A1 - Rauth, R.
A1 - Reimer, A.
A1 - Reimer, O.
A1 - Renaud, M.
A1 - de los Reyes, R.
A1 - Rieger, F.
A1 - Rinchiuso, L.
A1 - Romoli, C.
A1 - Rowell, G.
A1 - Rudak, B.
A1 - Rulten, C. B.
A1 - Sahakian, V.
A1 - Saito, S.
A1 - Sanchez, D. A.
A1 - Santangelo, Andrea
A1 - Sasaki, M.
A1 - Schlickeiser, R.
A1 - Schussler, F.
A1 - Schulz, A.
A1 - Schwanke, U.
A1 - Schwemmer, S.
A1 - Seglar-Arroyo, M.
A1 - Seyffert, A. S.
A1 - Shafi, N.
A1 - Shilon, I.
A1 - Shiningayamwe, K.
A1 - Simoni, R.
A1 - Sol, H.
A1 - Spanier, F.
A1 - Spir-Jacob, M.
A1 - Stawarz, L.
A1 - Steenkamp, R.
A1 - Stegmann, Christian
A1 - Steppa, Constantin Beverly
A1 - Sushch, I.
A1 - Takahashi, T.
A1 - Tavernet, J. -P.
A1 - Tavernier, T.
A1 - Taylor, A. M.
A1 - Terrier, R.
A1 - Tibaldo, L.
A1 - Tiziani, D.
A1 - Tluczykont, M.
A1 - Trichard, C.
A1 - Tsirou, M.
A1 - Tsuji, N.
A1 - Tuffs, R.
A1 - Uchiyama, Y.
A1 - van der Walt, D. J.
A1 - van Eldik, C.
A1 - van Rensburg, C.
A1 - van Soelen, B.
A1 - Vasileiadis, G.
A1 - Veh, J.
A1 - Venter, C.
A1 - Viana, A.
A1 - Vincent, P.
A1 - Vink, J.
A1 - Voisin, F.
A1 - Voelk, H. J.
A1 - Vuillaume, T.
A1 - Wadiasingh, Z.
A1 - Wagner, S. J.
A1 - Wagner, P.
A1 - Wagner, R. M.
A1 - White, R.
A1 - Wierzcholska, A.
A1 - Willmann, P.
A1 - Woernlein, A.
A1 - Wouters, D.
A1 - Yang, R.
A1 - Zaborov, D.
A1 - Zacharias, M.
A1 - Zanin, R.
A1 - Zdziarski, A. A.
A1 - Zech, Alraune
A1 - Zefi, F.
A1 - Ziegler, A.
A1 - Zorn, J.
A1 - Zywucka, N.
A1 - Enokiya, R.
A1 - Fukui, Y.
A1 - Hayakawa, T.
A1 - Okuda, T.
A1 - Torii, K.
A1 - Yamamoto, H.
T1 - HESS J1741-302: a hidden accelerator in the Galactic plane
JF - Astronomy and astrophysics : an international weekly journal
N2 - The H.E.S.S. Collaboration has discovered a new very high energy (VHE, E > 0.1 TeV) gamma-ray source, HESS J1741-302, located in the Galactic plane. Despite several attempts to constrain its nature, no plausible counterpart has been found so far at X-ray and MeV/GeV gamma-ray energies, and the source remains unidentified. An analysis of 145-h of observations of HESS J1741-302 at VHEs has revealed a steady and relatively weak TeV source (similar to 1% of the Crab Nebula flux), with a spectral index of Gamma = 2.3 +/- 0.2(stat) +/- 0.2(sys), extending to energies up to 10 TeV without any clear signature of a cut-off. In a hadronic scenario, such a spectrum implies an object with particle acceleration up to energies of several hundred TeV. Contrary to most H.E.S.S. unidentified sources, the angular size of HESS J1741-302 is compatible with the H.E.S.S. point spread function at VHEs, with an extension constrained to be below 0.068 degrees at a 99% confidence level. The gamma-ray emission detected by H.E.S.S. can be explained both within a hadronic scenario, due to collisions of protons with energies of hundreds of TeV with dense molecular clouds, and in a leptonic scenario, as a relic pulsar wind nebula, possibly powered by the middle-aged (20 kyr) pulsar PSR B1737-30. A binary scenario, related to the compact radio source 1LC 358.266+0.038 found to be spatially coincident with the best fit position of HESS J1741-302, is also envisaged.
KW - gamma rays: ISM
KW - gamma rays: general
KW - cosmic rays
KW - ISM: clouds
Y1 - 2018
U6 - https://doi.org/10.1051/0004-6361/201730581
SN - 1432-0746
VL - 612
PB - EDP Sciences
CY - Les Ulis
ER -
TY - JOUR
A1 - Abdalla, Hassan E.
A1 - Abramowski, A.
A1 - Aharonian, Felix A.
A1 - Benkhali, F. Ait
A1 - Akhperjanian, A. G.
A1 - Andersson, T.
A1 - Anguener, E. O.
A1 - Arakawa, M.
A1 - Arrieta, M.
A1 - Aubert, P.
A1 - Backes, M.
A1 - Balzer, A.
A1 - Barnard, M.
A1 - Becherini, Y.
A1 - Tjus, J. Becker
A1 - Berge, D.
A1 - Bernhard, S.
A1 - Bernloehr, K.
A1 - Blackwell, R.
A1 - Bottcher, M.
A1 - Boisson, C.
A1 - Bolmont, J.
A1 - Bordas, Pol
A1 - Bregeon, J.
A1 - Brun, F.
A1 - Brun, P.
A1 - Bryan, M.
A1 - Buechele, M.
A1 - Bulik, T.
A1 - Capasso, M.
A1 - Carr, J.
A1 - Casanova, Sabrina
A1 - Cerruti, M.
A1 - Chakraborty, N.
A1 - Chalme-Calvet, R.
A1 - Chaves, R. C. G.
A1 - Chen, A.
A1 - Chevalier, J.
A1 - Chretien, M.
A1 - Coffaro, M.
A1 - Colafrancesco, S.
A1 - Cologna, G.
A1 - Condon, B.
A1 - Conrad, J.
A1 - Cui, Y.
A1 - Davids, I. D.
A1 - Decock, J.
A1 - Degrange, B.
A1 - Deil, C.
A1 - Devin, J.
A1 - deWilt, P.
A1 - Dirson, L.
A1 - Djannati-Atai, A.
A1 - Domainko, W.
A1 - Donath, A.
A1 - Dutson, K.
A1 - Dyks, J.
A1 - Edwards, T.
A1 - Egberts, Kathrin
A1 - Eger, P.
A1 - Ernenwein, J. -P.
A1 - Eschbach, S.
A1 - Farnier, C.
A1 - Fegan, S.
A1 - Fernandes, M. V.
A1 - Fiasson, A.
A1 - Fontaine, G.
A1 - Foerster, A.
A1 - Funk, S.
A1 - Fuessling, M.
A1 - Gabici, S.
A1 - Gajdus, M.
A1 - Gallant, Y. A.
A1 - Garrigoux, T.
A1 - Giavitto, G.
A1 - Giebels, B.
A1 - Glicenstein, J. F.
A1 - Gottschall, D.
A1 - Goyal, A.
A1 - Grondin, M. -H.
A1 - Hahn, J.
A1 - Haupt, M.
A1 - Hawkes, J.
A1 - Heinzelmann, G.
A1 - Henri, G.
A1 - Hermann, G.
A1 - Hervet, O.
A1 - Hinton, J. A.
A1 - Hofmann, W.
A1 - Hoischen, Clemens
A1 - Holler, M.
A1 - Horns, D.
A1 - Ivascenko, A.
A1 - Iwasaki, H.
A1 - Jacholkowska, A.
A1 - Jamrozy, M.
A1 - Janiak, M.
A1 - Jankowsky, D.
A1 - Jankowsky, F.
A1 - Jingo, M.
A1 - Jogler, T.
A1 - Jouvin, L.
A1 - Jung-Richardt, I.
A1 - Kastendieck, M. A.
A1 - Katarzynski, K.
A1 - Katsuragawa, M.
A1 - Katz, U.
A1 - Kerszberg, D.
A1 - Khangulyan, D.
A1 - Khelifi, B.
A1 - Kieffer, M.
A1 - King, J.
A1 - Klepser, S.
A1 - Klochkov, D.
A1 - Kluzniak, W.
A1 - Kolitzus, D.
A1 - Komin, Nu.
A1 - Kosack, K.
A1 - Krakau, S.
A1 - Kraus, M.
A1 - Kruger, P. P.
A1 - Laffon, H.
A1 - Lamanna, G.
A1 - Lau, J.
A1 - Lees, J. -P.
A1 - Lefaucheur, J.
A1 - Lefranc, V.
A1 - Lemiere, A.
A1 - Lemoine-Goumard, M.
A1 - Lenain, J. -P.
A1 - Leser, Eva
A1 - Lohse, T.
A1 - Lorentz, M.
A1 - Liu, R.
A1 - Lopez-Coto, R.
A1 - Lypova, I.
A1 - Marandon, V.
A1 - Marcowith, Alexandre
A1 - Mariaud, C.
A1 - Marx, R.
A1 - Maurin, G.
A1 - Maxted, N.
A1 - Mayer, M.
A1 - Meintjes, P. J.
A1 - Meyer, M.
A1 - Mitchell, A. M. W.
A1 - Moderski, R.
A1 - Mohamed, M.
A1 - Mohrmann, L.
A1 - Mora, K.
A1 - Moulin, Emmanuel
A1 - Murach, T.
A1 - Nakashima, S.
A1 - de Naurois, M.
A1 - Niederwanger, F.
A1 - Niemiec, J.
A1 - Oakes, L.
A1 - Odaka, H.
A1 - Oettl, S.
A1 - Ohm, S.
A1 - Ostrowski, M.
A1 - Oya, I.
A1 - Padovani, M.
A1 - Panter, M.
A1 - Parsons, R. D.
A1 - Pekeur, N. W.
A1 - Pelletier, G.
A1 - Perennes, C.
A1 - Petrucci, P. -O.
A1 - Peyaud, B.
A1 - Piel, Q.
A1 - Pita, S.
A1 - Poon, H.
A1 - Prokhorov, D.
A1 - Prokoph, H.
A1 - Puehlhofer, G.
A1 - Punch, M.
A1 - Quirrenbach, A.
A1 - Raab, S.
A1 - Reimer, A.
A1 - Reimer, O.
A1 - Renaud, M.
A1 - de los Reyes, R.
A1 - Richter, S.
A1 - Rieger, F.
A1 - Romoli, C.
A1 - Rowell, G.
A1 - Rudak, B.
A1 - Rulten, C. B.
A1 - Sahakian, V.
A1 - Saito, S.
A1 - Salek, D.
A1 - Sanchez, D. A.
A1 - Santangelo, Andrea
A1 - Sasaki, M.
A1 - Schlickeiser, R.
A1 - Schussler, F.
A1 - Schulz, A.
A1 - Schwanke, U.
A1 - Schwemmer, S.
A1 - Seglar-Arroyo, M.
A1 - Settimo, M.
A1 - Seyffert, A. S.
A1 - Shafi, N.
A1 - Shilon, I.
A1 - Simoni, R.
A1 - Sol, H.
A1 - Spanier, F.
A1 - Spengler, G.
A1 - Spies, F.
A1 - Stawarz, L.
A1 - Steenkamp, R.
A1 - Stegmann, Christian Michael
A1 - Stycz, K.
A1 - Sushch, I.
A1 - Takahashi, T.
A1 - Tavernet, J. -P.
A1 - Tavernier, T.
A1 - Taylor, A. M.
A1 - Terrier, R.
A1 - Tibaldo, L.
A1 - Tiziani, D.
A1 - Tluczykont, M.
A1 - Trichard, C.
A1 - Tsuji, N.
A1 - Tuffs, R.
A1 - Uchiyama, Y.
A1 - van der Walt, D. J.
A1 - van Eldik, C.
A1 - van Rensburg, C.
A1 - van Soelen, B.
A1 - Vasileiadis, G.
A1 - Veh, J.
A1 - Venter, C.
A1 - Viana, A.
A1 - Vincent, P.
A1 - Vink, J.
A1 - Voisin, F.
A1 - Voelk, H. J.
A1 - Vuillaume, T.
A1 - Wadiasingh, Z.
A1 - Wagner, S. J.
A1 - Wagner, P.
A1 - Wagner, R. M.
A1 - White, R.
A1 - Wierzcholska, A.
A1 - Willmann, P.
A1 - Woernlein, A.
A1 - Wouters, D.
A1 - Yang, R.
A1 - Zabalza, V.
A1 - Zaborov, D.
A1 - Zacharias, M.
A1 - Zanin, R.
A1 - Zdziarski, A. A.
A1 - Zech, Alraune
A1 - Zefi, F.
A1 - Ziegler, A.
A1 - Zywucka, N.
T1 - Systematic search for very-high-energy gamma-ray emission from bow shocks of runaway stars
JF - Astronomy and astrophysics : an international weekly journal
N2 - Context. Runaway stars form bow shocks by ploughing through the interstellar medium at supersonic speeds and are promising sources of non-thermal emission of photons. One of these objects has been found to emit non-thermal radiation in the radio band. This triggered the development of theoretical models predicting non-thermal photons from radio up to very-high-energy (VHE, E >= 0.1 TeV) gamma rays. Subsequently, one bow shock was also detected in X-ray observations. However, the data did not allow discrimination between a hot thermal and a non-thermal origin. Further observations of different candidates at X-ray energies showed no evidence for emission at the position of the bow shocks either. A systematic search in the Fermi-LAT energy regime resulted in flux upper limits for 27 candidates listed in the E-BOSS catalogue. Aims. Here we perform the first systematic search for VHE gamma-ray emission from bow shocks of runaway stars. Methods. Using all available archival H.E.S.S. data we search for very-high-energy gamma-ray emission at the positions of bow shock candidates listed in the second E-BOSS catalogue release. Out of the 73 bow shock candidates in this catalogue, 32 have been observed with H.E.S.S. Results. None of the observed 32 bow shock candidates in this population study show significant emission in the H.E.S.S. energy range. Therefore, flux upper limits are calculated in five energy bins and the fraction of the kinetic wind power that is converted into VHE gamma rays is constrained. Conclusions. Emission from stellar bow shocks is not detected in the energy range between 0.14 and 18 TeV. The resulting upper limits constrain the level of VHE gamma-ray emission from these objects down to 0.1-1% of the kinetic wind energy.
KW - radiation mechanisms: non-thermal
KW - gamma rays: ISM
KW - stars: early-type
KW - gamma rays: stars
Y1 - 2018
U6 - https://doi.org/10.1051/0004-6361/201630151
SN - 1432-0746
VL - 612
PB - EDP Sciences
CY - Les Ulis
ER -
TY - JOUR
A1 - Abdalla, Hassan E.
A1 - Abramowski, A.
A1 - Aharonian, Felix A.
A1 - Benkhali, F. Ait
A1 - Akhperjanian, A. G.
A1 - Andersson, T.
A1 - Anguener, E. O.
A1 - Arakawa, M.
A1 - Arrieta, M.
A1 - Aubert, P.
A1 - Backes, M.
A1 - Balzer, A.
A1 - Barnard, M.
A1 - Becherini, Y.
A1 - Tjus, J. Becker
A1 - Berge, D.
A1 - Bernhard, S.
A1 - Bernloehr, K.
A1 - Blackwell, R.
A1 - Boettcher, M.
A1 - Boisson, C.
A1 - Bolmont, J.
A1 - Bonnefoy, S.
A1 - Bordas, Pol
A1 - Bregeon, J.
A1 - Brun, F.
A1 - Brun, P.
A1 - Bryan, M.
A1 - Buechele, M.
A1 - Bulik, T.
A1 - Capasso, M.
A1 - Carr, J.
A1 - Casanova, Sabrina
A1 - Cerruti, M.
A1 - Chakraborty, N.
A1 - Chaves, R. C. G.
A1 - Chen, A.
A1 - Chevalier, J.
A1 - Coffaro, M.
A1 - Colafrancesco, S.
A1 - Cologna, G.
A1 - Condon, B.
A1 - Conrad, J.
A1 - Cui, Y.
A1 - Davids, I. D.
A1 - Decock, J.
A1 - Degrange, B.
A1 - Deil, C.
A1 - Devin, J.
A1 - deWilt, P.
A1 - Dirson, L.
A1 - Djannati-Atai, A.
A1 - Domainko, W.
A1 - Donath, A.
A1 - Dutson, K.
A1 - Dyks, J.
A1 - Edwards, T.
A1 - Egberts, Kathrin
A1 - Eger, P.
A1 - Ernenwein, J. -P.
A1 - Eschbach, S.
A1 - Farnier, C.
A1 - Fegan, S.
A1 - Fernandes, M. V.
A1 - Fiasson, A.
A1 - Fontaine, G.
A1 - Foerster, A.
A1 - Funk, S.
A1 - Fuessling, M.
A1 - Gabici, S.
A1 - Gajdus, M.
A1 - Gallant, Y. A.
A1 - Garrigoux, T.
A1 - Giavitto, G.
A1 - Giebels, B.
A1 - Glicenstein, J. F.
A1 - Gottschall, D.
A1 - Goyal, A.
A1 - Grondin, M. -H.
A1 - Hahn, J.
A1 - Haupt, M.
A1 - Hawkes, J.
A1 - Heinzelmann, G.
A1 - Henri, G.
A1 - Hermann, G.
A1 - Hervet, O.
A1 - Hinton, J. A.
A1 - Hofmann, W.
A1 - Hoischen, Clemens
A1 - Holch, T. L.
A1 - Holler, M.
A1 - Horns, D.
A1 - Ivascenko, A.
A1 - Iwasaki, H.
A1 - Jacholkowska, A.
A1 - Jamrozy, M.
A1 - Janiak, M.
A1 - Jankowsky, D.
A1 - Jankowsky, F.
A1 - Jingo, M.
A1 - Jogler, T.
A1 - Jouvin, L.
A1 - Jung-Richardt, I.
A1 - Kastendieck, M. A.
A1 - Katarzynski, K.
A1 - Katsuragawa, M.
A1 - Katz, U.
A1 - Kerszberg, D.
A1 - Khangulyan, D.
A1 - Khelifi, B.
A1 - King, J.
A1 - Klepser, S.
A1 - Klochkov, D.
A1 - Kluzniak, W.
A1 - Kolitzus, D.
A1 - Komin, Nu.
A1 - Kosack, K.
A1 - Krakau, S.
A1 - Kraus, M.
A1 - Krueger, P. P.
A1 - Laffon, H.
A1 - Lamanna, G.
A1 - Lau, J.
A1 - Lees, J. -P.
A1 - Lefaucheur, J.
A1 - Lefranc, V.
A1 - Lemiere, A.
A1 - Lemoine-Goumard, M.
A1 - Lenain, J. -P.
A1 - Leser, Eva
A1 - Lohse, T.
A1 - Lorentz, M.
A1 - Liu, R.
A1 - Lopez-Coto, R.
A1 - Lypova, I.
A1 - Marandon, V.
A1 - Marcowith, Alexandre
A1 - Mariaud, C.
A1 - Marx, R.
A1 - Maurin, G.
A1 - Maxted, N.
A1 - Mayer, M.
A1 - Meintjes, P. J.
A1 - Meyer, M.
A1 - Mitche, A. M. W.
A1 - Moderski, R.
A1 - Mohamed, M.
A1 - Mohrmann, L.
A1 - Mora, K.
A1 - Moulin, Emmanuel
A1 - Murach, T.
A1 - Nakashima, S.
A1 - de Naurois, M.
A1 - Niederwanger, F.
A1 - Niemiec, J.
A1 - Oakes, L.
A1 - Odaka, H.
A1 - Oettl, S.
A1 - Ohm, S.
A1 - Ostrowski, M.
A1 - Oya, I.
A1 - Padovani, M.
A1 - Panter, M.
A1 - Parsons, R. D.
A1 - Pekeur, N. W.
A1 - Pelletier, G.
A1 - Perennes, C.
A1 - Petrucci, P. -O.
A1 - Peyaud, B.
A1 - Piel, Q.
A1 - Pita, S.
A1 - Poon, H.
A1 - Prokhorov, D.
A1 - Prokoph, H.
A1 - Puehlhofer, G.
A1 - Punch, M.
A1 - Quirrenbach, A.
A1 - Raab, S.
A1 - Reimer, A.
A1 - Reimer, O.
A1 - Renaud, M.
A1 - de los Reyes, R.
A1 - Richter, S.
A1 - Rieger, F.
A1 - Romoli, C.
A1 - Rowell, G.
A1 - Rudak, B.
A1 - Rulten, C. B.
A1 - Sahakian, V.
A1 - Saito, S.
A1 - Salek, D.
A1 - Sanchez, D. A.
A1 - Santangelo, Andrea
A1 - Sasaki, M.
A1 - Schlickeiser, R.
A1 - Schuessler, F.
A1 - Schulz, A.
A1 - Schwanke, U.
A1 - Schwemmer, S.
A1 - Seglar-Arroyo, M.
A1 - Settimo, M.
A1 - Seyffert, A. S.
A1 - Shafi, N.
A1 - Shilon, I.
A1 - Simoni, R.
A1 - Sol, H.
A1 - Spanier, F.
A1 - Spengler, G.
A1 - Spies, F.
A1 - Stawarz, L.
A1 - Steenkamp, R.
A1 - Stegmann, Christian
A1 - Stycz, K.
A1 - Sushch, I.
A1 - Takahashi, T.
A1 - Tavernet, J. -P.
A1 - Tavernier, T.
A1 - Taylor, A. M.
A1 - Terrier, R.
A1 - Tibaldo, L.
A1 - Tiziani, D.
A1 - Tluczykont, M.
A1 - Trichard, C.
A1 - Tsuji, N.
A1 - Tuffs, R.
A1 - Uchiyama, Y.
A1 - van der Wale, D. J.
A1 - van Eldik, C.
A1 - van Rensburg, C.
A1 - van Soelen, B.
A1 - Vasileiadis, G.
A1 - Veh, J.
A1 - Venter, C.
A1 - Viana, A.
A1 - Vincent, P.
A1 - Vink, J.
A1 - Voisin, F.
A1 - Voelk, H. J.
A1 - Vuillaume, T.
A1 - Wadiasingh, Z.
A1 - Wagner, S. J.
A1 - Wagner, P.
A1 - Wagner, R. M.
A1 - White, R.
A1 - Wierzcholska, A.
A1 - Willmann, P.
A1 - Woernlein, A.
A1 - Wouters, D.
A1 - Yang, R.
A1 - Zabalza, V.
A1 - Zaborov, D.
A1 - Zacharias, M.
A1 - Zanin, R.
A1 - Zdziarski, A. A.
A1 - Zech, Alraune
A1 - Zefi, F.
A1 - Ziegler, A.
A1 - Zywucka, N.
A1 - Bamba, A.
A1 - Fukui, Y.
A1 - Sano, H.
A1 - Yoshiike, S.
T1 - A search for new supernova remnant shells in the Galactic plane with HESS
JF - Astronomy and astrophysics : an international weekly journal
N2 - A search for new supernova remnants (SNRs) has been conducted using TeV gamma-ray data from the H.E.S.S. Galactic plane survey. As an identification criterion, shell morphologies that are characteristic for known resolved TeV SNRs have been used. Three new SNR candidates were identified in the H.E.S.S. data set with this method. Extensive multiwavelength searches for counterparts were conducted. A radio SNR candidate has been identified to be a counterpart to HESS J1534-571. The TeV source is therefore classified as a SNR. For the other two sources, HESS J1614-518 and HESS J1912 + 101, no identifying counterparts have been found, thus they remain SNR candidates for the time being. TeV-emitting SNRs are key objects in the context of identifying the accelerators of Galactic cosmic rays. The TeV emission of the relativistic particles in the new sources is examined in view of possible leptonic and hadronic emission scenarios, taking the current multiwavelength knowledge into account.
KW - astroparticle physics
KW - ISM: supernova remnants
KW - cosmic rays
Y1 - 2018
U6 - https://doi.org/10.1051/0004-6361/201730737
SN - 1432-0746
VL - 612
PB - EDP Sciences
CY - Les Ulis
ER -
TY - JOUR
A1 - Abdalla, Hassan E.
A1 - Abramowski, A.
A1 - Aharonian, Felix A.
A1 - Benkhali, F. Ait
A1 - Akhperjanian, A. G.
A1 - Anguener, E. O.
A1 - Arrieta, M.
A1 - Aubert, P.
A1 - Backes, M.
A1 - Balzer, A.
A1 - Barnard, M.
A1 - Becherini, Y.
A1 - Tjus, J. Becker
A1 - Berge, D.
A1 - Bernhard, S.
A1 - Bernloehr, K.
A1 - Birsin, E.
A1 - Blackwell, R.
A1 - Bottcher, M.
A1 - Boisson, C.
A1 - Bolmont, J.
A1 - Bordas, Pol
A1 - Bregeon, J.
A1 - Brun, F.
A1 - Brun, P.
A1 - Bryan, M.
A1 - Bulik, T.
A1 - Capasso, M.
A1 - Carr, J.
A1 - Casanova, Sabrina
A1 - Chakraborty, N.
A1 - Chalme-Calvet, R.
A1 - Chaves, R. C. G.
A1 - Chen, A.
A1 - Chevalier, J.
A1 - Chretien, M.
A1 - Colafrancesco, S.
A1 - Cologna, G.
A1 - Condon, B.
A1 - Conrad, J.
A1 - Couturier, C.
A1 - Cui, Y.
A1 - Davids, I. D.
A1 - Degrange, B.
A1 - Deil, C.
A1 - deWilt, P.
A1 - Djannati-Atai, A.
A1 - Domainko, W.
A1 - Donath, A.
A1 - Dubus, G.
A1 - Dutson, K.
A1 - Dyks, J.
A1 - Dyrda, M.
A1 - Edwards, T.
A1 - Egberts, Kathrin
A1 - Eger, P.
A1 - Ernenwein, J. -P.
A1 - Eschbach, S.
A1 - Farnier, C.
A1 - Fegan, S.
A1 - Fernandes, M. V.
A1 - Fiasson, A.
A1 - Fontaine, G.
A1 - Foerster, A.
A1 - Funk, S.
A1 - Fuessling, M.
A1 - Gabici, S.
A1 - Gajdus, M.
A1 - Gallant, Y. A.
A1 - Garrigoux, T.
A1 - Giavitto, G.
A1 - Giebels, B.
A1 - Glicenstein, J. F.
A1 - Gottschall, D.
A1 - Goyal, A.
A1 - Grondin, M. -H.
A1 - Grudzinska, M.
A1 - Hadasch, D.
A1 - Hahn, J.
A1 - Hawkes, J.
A1 - Heinzelmann, G.
A1 - Henri, G.
A1 - Hermann, G.
A1 - Hervet, O.
A1 - Hillert, A.
A1 - Hinton, J. A.
A1 - Hofmann, W.
A1 - Hoischen, Clemens
A1 - Holler, M.
A1 - Horns, D.
A1 - Ivascenko, A.
A1 - Jacholkowska, A.
A1 - Jamrozy, M.
A1 - Janiak, M.
A1 - Jankowsky, D.
A1 - Jankowsky, F.
A1 - Jingo, M.
A1 - Jogler, T.
A1 - Jouvin, L.
A1 - Jung-Richardt, I.
A1 - Kastendieck, M. A.
A1 - Katarzynski, K.
A1 - Katz, U.
A1 - Kerszberg, D.
A1 - Khelifi, B.
A1 - Kieffer, M.
A1 - King, J.
A1 - Klepser, S.
A1 - Klochkov, D.
A1 - Kluzniak, W.
A1 - Kolitzus, D.
A1 - Komin, Nu.
A1 - Kosack, K.
A1 - Krakau, S.
A1 - Kraus, M.
A1 - Krayzel, F.
A1 - Kruger, P. P.
A1 - Laffon, H.
A1 - Lamanna, G.
A1 - Lau, J.
A1 - Lees, J. -P.
A1 - Lefaucheur, J.
A1 - Lefranc, V.
A1 - Lemiere, A.
A1 - Lemoine-Goumard, M.
A1 - Lenain, J. -P.
A1 - Leser, E.
A1 - Lohse, T.
A1 - Lorentz, M.
A1 - Liu, R.
A1 - Lypova, I.
A1 - Marandon, V.
A1 - Marcowith, Alexandre
A1 - Mariaud, C.
A1 - Marx, R.
A1 - Maurin, G.
A1 - Maxted, N.
A1 - Mayer, M.
A1 - Meintjes, P. J.
A1 - Menzler, U.
A1 - Meyer, M.
A1 - Mitchell, A. M. W.
A1 - Moderski, R.
A1 - Mohamed, M.
A1 - Mora, K.
A1 - Moulin, Emmanuel
A1 - Murach, T.
A1 - de Naurois, M.
A1 - Niederwanger, F.
A1 - Niemiec, J.
A1 - Oakes, L.
A1 - Odaka, H.
A1 - Oettl, S.
A1 - Ohm, S.
A1 - Ostrowski, M.
A1 - Oya, I.
A1 - Padovani, M.
A1 - Panter, M.
A1 - Parsons, R. D.
A1 - Arribas, M. Paz
A1 - Pekeur, N. W.
A1 - Pelletier, G.
A1 - Petrucci, P. -O.
A1 - Peyaud, B.
A1 - Pita, S.
A1 - Poon, H.
A1 - Prokhorov, D.
A1 - Prokoph, H.
A1 - Puehlhofer, G.
A1 - Punch, M.
A1 - Quirrenbach, A.
A1 - Raab, S.
A1 - Reimer, A.
A1 - Reimer, O.
A1 - Renaud, M.
A1 - de los Reyes, R.
A1 - Rieger, F.
A1 - Romoli, C.
A1 - Rosier-Lees, S.
A1 - Rowell, G.
A1 - Rudak, B.
A1 - Rulten, C. B.
A1 - Sahakian, V.
A1 - Salek, D.
A1 - Sanchez, D. A.
A1 - Santangelo, Andrea
A1 - Sasaki, M.
A1 - Schlickeiser, R.
A1 - Schussler, F.
A1 - Schulz, A.
A1 - Schwanke, U.
A1 - Schwemmer, S.
A1 - Seyffert, A. S.
A1 - Shafi, N.
A1 - Shilon, I.
A1 - Simoni, R.
A1 - Sol, H.
A1 - Spanier, F.
A1 - Spengler, G.
A1 - Spies, F.
A1 - Stawarz, L.
A1 - Steenkamp, R.
A1 - Stegmann, Christian
A1 - Stinzing, F.
A1 - Stycz, K.
A1 - Sushch, I.
A1 - Tavernet, J. -P.
A1 - Tavernier, T.
A1 - Taylor, A. M.
A1 - Terrier, R.
A1 - Tluczykont, M.
A1 - Trichard, C.
A1 - Tuffs, R.
A1 - van der Walt, J.
A1 - van Eldik, C.
A1 - van Soelen, B.
A1 - Vasileiadis, G.
A1 - Veh, J.
A1 - Venter, C.
A1 - Viana, A.
A1 - Vincent, P.
A1 - Vink, J.
A1 - Voisin, F.
A1 - Voelk, H. J.
A1 - Vuillaume, T.
A1 - Wadiasingh, Z.
A1 - Wagner, S. J.
A1 - Wagner, P.
A1 - Wagner, R. M.
A1 - White, R.
A1 - Wierzcholska, A.
A1 - Willmann, P.
A1 - Woernlein, A.
A1 - Wouters, D.
A1 - Yang, R.
A1 - Zabalza, V.
A1 - Zaborov, D.
A1 - Zacharias, M.
A1 - Zdziarski, A. A.
A1 - Zech, Alraune
A1 - Zefi, F.
A1 - Ziegler, A.
A1 - Zywucka, N.
T1 - Extended VHE gamma-ray emission towards SGR1806-20, LBV 1806-20, and stellar cluster Cl*1806-20
JF - Astronomy and astrophysics : an international weekly journal
N2 - Using the High Energy Spectroscopic System (H.E.S.S.) telescopes we have discovered a steady and extended very high-energy (VHE) gamma-ray source towards the luminous blue variable candidate LBV 1806-20, massive stellar cluster Cl* 1806-20, and magnetar SGR 1806-20. The new VHE source, HESS J1808-204, was detected at a statistical significance of >6 sigma (post-trial) with a photon flux normalisation (2.9 +/- 0.4(stat) +/- 0.5(sys)) x 10(-13) ph cm(-2) s(-1) TeV-1 at 1 TeV and a power-law photon index of 2.3 +/- 0.2(stat) +/- 0.3(sys). The luminosity of this source (0.2 to 10 TeV; scaled to distance d = 8 : 7 kpc) is L-VHE similar to 1.6 x 10(34)(d = 8.7 kpc)(2) erg s(-1). The VHE gamma-ray emission is extended and is well fit by a single Gaussian with statistical standard deviation of 0.095 degrees +/- 0.015 degrees. This extension is similar to that of the synchrotron radio nebula G10.0-0.3, which is thought to be powered by LBV 1806-20. The VHE gamma-ray luminosity could be provided by the stellar wind luminosity of LBV 1806-20 by itself and/or the massive star members of Cl* 1806-20. Alternatively, magnetic dissipation (e.g. via reconnection) from SGR 1806-20 can potentially account for the VHE luminosity. The origin and hadronic and/or leptonic nature of the accelerated particles responsible for HESS J1808-204 is not yet clear. If associated with SGR 1806 20, the potentially young age of the magnetar (650 yr) can be used to infer the transport limits of these particles to match the VHE source size. This discovery provides new interest in the potential for high-energy particle acceleration from magnetars, massive stars, and/or stellar clusters.
KW - gamma rays: general
KW - stars: magnetars
KW - stars: massive
Y1 - 2018
U6 - https://doi.org/10.1051/0004-6361/201628695
SN - 1432-0746
VL - 612
PB - EDP Sciences
CY - Les Ulis
ER -
TY - JOUR
A1 - Abdalla, Hassan E.
A1 - Abramowski, A.
A1 - Aharonian, Felix A.
A1 - Benkhali, F. Ait
A1 - Akhperjanian, A. G.
A1 - Andersson, T.
A1 - Anguener, E. O.
A1 - Arrieta, M.
A1 - Aubert, P.
A1 - Backes, M.
A1 - Balzer, A.
A1 - Barnard, M.
A1 - Becherini, Y.
A1 - Tjus, J. Becker
A1 - Berge, D.
A1 - Bernhard, S.
A1 - Bernloehr, K.
A1 - Blackwell, R.
A1 - Boettcher, M.
A1 - Boisson, C.
A1 - Bolmont, J.
A1 - Bordas, Pol
A1 - Bregeon, J.
A1 - Brun, F.
A1 - Brun, P.
A1 - Bryan, M.
A1 - Bulik, T.
A1 - Capasso, M.
A1 - Carr, J.
A1 - Casanova, Sabrina
A1 - Cerruti, M.
A1 - Chakraborty, N.
A1 - Chalme-Calvet, R.
A1 - Chaves, R. C. G.
A1 - Chen, A.
A1 - Chevalier, J.
A1 - Chretien, M.
A1 - Colafrancesco, S.
A1 - Cologna, G.
A1 - Condon, B.
A1 - Conrad, J.
A1 - Cui, Y.
A1 - Davids, I. D.
A1 - Decock, J.
A1 - Degrange, B.
A1 - Dei, C.
A1 - Devin, J.
A1 - deWilt, P.
A1 - Dirson, L.
A1 - Djannati-Atai, A.
A1 - Domainko, W.
A1 - Donath, A.
A1 - Dubus, G.
A1 - Dutson, K.
A1 - Dyks, J.
A1 - Edwards, T.
A1 - Egberts, Kathrin
A1 - Eger, P.
A1 - Ernenwein, J. -P.
A1 - Eschbach, S.
A1 - Farnier, C.
A1 - Fegan, S.
A1 - Fernandes, M. V.
A1 - Fiasson, A.
A1 - Fontaine, G.
A1 - Foerster, A.
A1 - Fukuyama, T.
A1 - Funk, S.
A1 - Fuessling, M.
A1 - Gabici, S.
A1 - Gajdus, M.
A1 - Gallant, Y. A.
A1 - Garrigoux, T.
A1 - Giavitto, G.
A1 - Giebels, B.
A1 - Glicenstein, J. F.
A1 - Gottschall, D.
A1 - Goyal, A.
A1 - Grondin, M. -H.
A1 - Hadasch, D.
A1 - Hahn, J.
A1 - Haupt, M.
A1 - Hawkes, J.
A1 - Heinzelmann, G.
A1 - Henri, G.
A1 - Hermann, G.
A1 - Hervet, O.
A1 - Hinton, J. A.
A1 - Hofmann, W.
A1 - Hoischen, Clemens
A1 - Holler, M.
A1 - Horns, D.
A1 - Ivascenko, A.
A1 - Jacholkowska, A.
A1 - Jamrozy, M.
A1 - Janiak, M.
A1 - Jankowsky, D.
A1 - Jankowsky, F.
A1 - Jingo, M.
A1 - Jogler, T.
A1 - Jouvin, L.
A1 - Jung-Richardt, I.
A1 - Kastendieck, M. A.
A1 - Katarzynski, K.
A1 - Katz, U.
A1 - Kerszberg, D.
A1 - Khelifi, B.
A1 - Kieffer, M.
A1 - King, J.
A1 - Klepser, S.
A1 - Klochkov, D.
A1 - Kluzniak, W.
A1 - Kolitzus, D.
A1 - Komin, Nu.
A1 - Kosack, K.
A1 - Krakau, S.
A1 - Kraus, M.
A1 - Krayzel, F.
A1 - Krueger, P. P.
A1 - Laffon, H.
A1 - Lamanna, G.
A1 - Lau, J.
A1 - Lees, J. -P.
A1 - Lefaucheur, J.
A1 - Lefranc, V.
A1 - Lemiere, A.
A1 - Lemoine-Goumard, M.
A1 - Lenain, J. -P.
A1 - Leser, Eva
A1 - Lohse, T.
A1 - Lorentz, M.
A1 - Liu, R.
A1 - Lopez-Coto, R.
A1 - Lypova, I.
A1 - Marandon, V.
A1 - Marcowith, Alexandre
A1 - Mariaud, C.
A1 - Marx, R.
A1 - Maurin, G.
A1 - Maxted, N.
A1 - Mayer, M.
A1 - Meintjes, P. J.
A1 - Meyer, M.
A1 - Mitchell, A. M. W.
A1 - Moderski, R.
A1 - Mohamed, M.
A1 - Mohrmann, L.
A1 - Mora, K.
A1 - Moulin, Emmanuel
A1 - Murach, T.
A1 - de Naurois, M.
A1 - Niederwanger, F.
A1 - Niemiec, J.
A1 - Oakes, L.
A1 - Odaka, H.
A1 - Oettl, S.
A1 - Ohm, S.
A1 - Ostrowski, M.
A1 - Oya, I.
A1 - Padovani, M.
A1 - Panter, M.
A1 - Parsons, R. D.
A1 - Pekeur, N. W.
A1 - Pelletier, G.
A1 - Perennes, C.
A1 - Petrucci, P. -O.
A1 - Peyaud, B.
A1 - Piel, Q.
A1 - Pita, S.
A1 - Poon, H.
A1 - Prokhorov, D.
A1 - Prokoph, H.
A1 - Puehlhofer, G.
A1 - Punch, M.
A1 - Quirrenbach, A.
A1 - Raab, S.
A1 - Reimer, A.
A1 - Reimer, O.
A1 - Renaud, M.
A1 - de los Reyes, R.
A1 - Rieger, F.
A1 - Romoli, C.
A1 - Rosier-Lees, S.
A1 - Rowell, G.
A1 - Rudak, B.
A1 - Rulten, C. B.
A1 - Sahakian, V.
A1 - Salek, D.
A1 - Sanchez, D. A.
A1 - Santangelo, Andrea
A1 - Sasaki, M.
A1 - Schlickeiser, R.
A1 - Schuessler, F.
A1 - Schulz, A.
A1 - Schwanke, U.
A1 - Schwemmer, S.
A1 - Settimo, M.
A1 - Seyffert, A. S.
A1 - Shafi, N.
A1 - Shilon, I.
A1 - Simoni, R.
A1 - Sol, H.
A1 - Spanie, F.
A1 - Spengler, G.
A1 - Spies, F.
A1 - Stawarz, L.
A1 - Steenkamp, R.
A1 - Stegmann, Christian
A1 - Stinzing, F.
A1 - Stycz, K.
A1 - Sushch, I.
A1 - Takahashi, T.
A1 - Tavernet, J. -P.
A1 - Tavernier, T.
A1 - Taylor, A. M.
A1 - Terrier, R.
A1 - Tibaldo, L.
A1 - Tiziani, D.
A1 - Tluczykont, M.
A1 - Trichard, C.
A1 - Tuffs, R.
A1 - Uchiyama, Y.
A1 - van der Walt, D. J.
A1 - van Edik, C.
A1 - van Rensburg, C.
A1 - van Soelen, B.
A1 - Vasileiadis, G.
A1 - Veh, J.
A1 - Venter, C.
A1 - Viana, A.
A1 - Vincent, P.
A1 - Vink, J.
A1 - Voisin, F.
A1 - Voelk, H. J.
A1 - Volpe, F.
A1 - Vuillaume, T.
A1 - Wadiasingh, Z.
A1 - Wagner, S. J.
A1 - Wagner, P.
A1 - Wagner, R. M.
A1 - White, R.
A1 - Wierzcholska, A.
A1 - Willmann, P.
A1 - Woernlein, A.
A1 - Wouters, D.
A1 - Yang, R.
A1 - Zabalza, V.
A1 - Zaborov, D.
A1 - Zacharias, M.
A1 - Zdziarski, A. A.
A1 - Zech, Alraune
A1 - Zefi, F.
A1 - Ziegler, A.
A1 - Zywucka, N.
T1 - HESS observations of RX J1713.7-3946 with improved angular and spectral resolution
BT - Evidence for gamma-ray emission extending beyond the X-ray emitting shell
JF - Astronomy and astrophysics : an international weekly journal
KW - acceleration of particles
KW - cosmic rays
KW - ISM: supernova remnants
KW - gamma rays: general
KW - astroparticle physic
Y1 - 2018
U6 - https://doi.org/10.1051/0004-6361/201629790
SN - 1432-0746
VL - 612
PB - EDP Sciences
CY - Les Ulis
ER -
TY - THES
A1 - Khosravi, Sara
T1 - The effect of new turbulence parameterizations for the stable surface layer on simulations of the Arctic climate
T1 - Die Auswirkung neuer Turbulenzparametrisierungen auf die stabile Grenzschicht in Simulationen des arktischen Klimas
N2 - Arctic climate change is marked by intensified warming compared to global trends and a significant reduction in Arctic sea ice which can intricately influence mid-latitude atmospheric circulation through tropo- and stratospheric pathways. Achieving accurate simulations of current and future climate demands a realistic representation of Arctic climate processes in numerical climate models, which remains challenging.
Model deficiencies in replicating observed Arctic climate processes often arise due to inadequacies in representing turbulent boundary layer interactions that determine the interactions between the atmosphere, sea ice, and ocean. Many current climate models rely on parameterizations developed for mid-latitude conditions to handle Arctic turbulent boundary layer processes.
This thesis focuses on modified representation of the Arctic atmospheric processes and understanding their resulting impact on large-scale mid-latitude atmospheric circulation within climate models. The improved turbulence parameterizations, recently developed based on Arctic measurements, were implemented in the global atmospheric circulation model ECHAM6. This involved modifying the stability functions over sea ice and ocean for stable stratification and changing the roughness length over sea ice for all stratification conditions. Comprehensive analyses are conducted to assess the impacts of these modifications on ECHAM6's simulations of the Arctic boundary layer, overall atmospheric circulation, and the dynamical pathways between the Arctic and mid-latitudes.
Through a step-wise implementation of the mentioned parameterizations into ECHAM6, a series of sensitivity experiments revealed that the combined impacts of the reduced roughness length and the modified stability functions are non-linear. Nevertheless, it is evident that both modifications consistently lead to a general decrease in the heat transfer coefficient, being in close agreement with the observations.
Additionally, compared to the reference observations, the ECHAM6 model falls short in accurately representing unstable and strongly stable conditions.
The less frequent occurrence of strong stability restricts the influence of the modified stability functions by reducing the affected sample size. However, when focusing solely on the specific instances of a strongly stable atmosphere, the sensible heat flux approaches near-zero values, which is in line with the observations. Models employing commonly used surface turbulence parameterizations were shown to have difficulties replicating the near-zero sensible heat flux in strongly stable stratification.
I also found that these limited changes in surface layer turbulence parameterizations have a statistically significant impact on the temperature and wind patterns across multiple pressure levels, including the stratosphere, in both the Arctic and mid-latitudes. These significant signals vary in strength, extent, and direction depending on the specific month or year, indicating a strong reliance on the background state.
Furthermore, this research investigates how the modified surface turbulence parameterizations may influence the response of both stratospheric and tropospheric circulation to Arctic sea ice loss.
The most suitable parameterizations for accurately representing Arctic boundary layer turbulence were identified from the sensitivity experiments. Subsequently, the model's response to sea ice loss is evaluated through extended ECHAM6 simulations with different prescribed sea ice conditions.
The simulation with adjusted surface turbulence parameterizations better reproduced the observed Arctic tropospheric warming in vertical extent, demonstrating improved alignment with the reanalysis data. Additionally, unlike the control experiments, this simulation successfully reproduced specific circulation patterns linked to the stratospheric pathway for Arctic-mid-latitude linkages. Specifically, an increased occurrence of the Scandinavian-Ural blocking regime (negative phase of the North Atlantic Oscillation) in early (late) winter is observed. Overall, it can be inferred that improving turbulence parameterizations at the surface layer can improve the ECHAM6's response to sea ice loss.
N2 - Der Klimawandel in der Arktis ist durch eine im Vergleich zum globalen Klimawandel verstärkte Erwärmung und einem damit verbundenen starken Rückgang des arktischen Meereises gekennzeichnet. Da dieser verstärkte Klimawandel in der Arktis die atmosphärische Zirkulation in den mittleren Breiten auf komplexe Weise über tropo- und stratosphärische Pfade beeinflussen kann, ist eine realistische Darstellung arktischer Prozesse in numerischen Klimamodellen für zuverlässige Simulationen gegenwärtiger und zukünftiger Klimaänderungen notwendig, stellt aber nach wie vor eine Herausforderung dar.
Ein wesentlicher Grund für Modelldefizite bei der Reproduktion der beobachteten arktischen Klimaprozesse sind Unzulänglichkeiten bei der Darstellung von turbulenten Grenzschichtprozessen, die die Wechselwirkung zwischen Atmosphäre, Meereis und Ozean bestimmen. Gegenwärtige Klimamodelle verwenden für die Darstellung von turbulenten Grenzschichtprozessen in der Arktis häufig Parametrisierungen, die für Bedingungen in mittleren Breiten entwickelt wurden.
Diese Arbeit zielt auf eine bessere Darstellung arktischer atmosphärischer Prozesse in Klimamodellen und ein besseres Verständnis der daraus resultierenden Auswirkungen auf die simulierte großskalige atmosphärische Zirkulation in mittleren Breiten ab. Aus diesem Grund wurde in dieser Arbeit eine Hierarchie von verbesserten Turbulenzparametrisierungen in das globale atmosphärische Zirkulationsmodell ECHAM6 implementiert, die basierend auf arktischen Messungen kürzlich entwickelt wurden. Dabei wurden die Stabilitätsfunktionen über Meereis und Ozean für stabile Schichtung sowie die Rauhigkeitslänge über dem Meereis für alle Schichtungsbedingungen modifiziert. Anschließend wurde eine umfassende Analyse der jeweiligen Sensitivitätsexperimente durchgeführt, um den Einfluss dieser Modifikationen auf die Simulationen der arktischen Grenzschicht, der großräumigen atmosphärischen Zirkulation und der dynamischen Verbindungswege zwischen der Arktis und den mittleren Breiten in ECHAM6 zu bewerten.
Durch eine schrittweise Implementierung der Hierarchie von verbesserten Turbulenzparameterisierungen in ECHAM6 wurden in einer Reihe von Sensitivitätsexperimenten folgende Erkenntnisse gewonnen: Die kombinierte Auswirkung der reduzierten Rauhigkeitslänge und der modifizierten Stabilitätsfunktionen ist nichtlinear. Dennoch zeigt sich, dass beide Modifikationen zu einer besseren Darstellung arktischer Grenzschichtprozesse führen, insbesondere stimmt die Verringerung des Transferkoeffizienten für Wärme gut mit den Beobachtungen überein. Im Vergleich zu den Referenzbeobachtungen zeigt das ECHAM6-Modell jedoch eine unrealistische Darstellung des Auftretens labiler und stark stabiler Schichtungsbedingungen. Die geringere Häufigkeit von stark stabilen Bedingungen begrenzt den Einfluss der modifizierten Stabilitätsfunktionen. Wenn in den Modelldaten nur die Fälle mit stark stabiler Schichtung analysiert werden, führt die Verwendung der modifizierten Stabilitätsfunktionen zu sehr kleinen turbulenten sensiblen Wärmeflüssen in guter Übereinstimmung mit den Beobachtungen. Dieses Verhalten wurde in den Modellsimulationen mit der Standardturbulenzparametrisierung nicht reproduziert. Es wurde zudem festgestellt, dass die Änderungen in den Turbulenzparametrisierungen einen statistisch signifikanten Einfluss auf die großskaligen Temperatur- und Windfelder in verschiedenen Höhen bis in die Stratosphäre sowohl in der Arktis als auch in den mittleren Breiten haben. Diese signifikanten Signale variieren in ihrer Stärke und Lage je nach Monat und Jahr, was eine starke Abhängigkeit vom Hintergrundzustand anzeigt.
Des Weiteren wird in dieser Arbeit untersucht, wie die modifizierten Turbulenzparametrisierungen die Reaktion der troposphärischen und stratosphärischen Zirkulation auf den Rückgang des arktischen Meereises beeinflussen. Dafür wurden die geeignetsten Parametrisierungen zur Darstellung der arktischen Grenzschichtturbulenz anhand der Sensitivitätsexperimente identifiziert. Anschließend wurde die Reaktion des Modells ECHAM6 auf den Meereisverlust durch weitere lange Simulationen mit unterschiedlichen vorgegebenen Meereisbedingungen bewertet. Dabei simuliert die ECHAM6 Modellversion mit verbesserter Turbulenzparametrisierung eine größere vertikale Ausdehnung der arktischen troposphärischen Erwärmung bei Meereisrückgang und zeigt somit eine verbesserte Übereinstimmung mit den Reanalyse-Daten. Darüber hinaus treten in dieser Simulation im Gegensatz zu den Kontrollexperimenten häufiger bevorzugte Zirkulationsmuster auf, die dafür bekannt sind, dass sie Änderungen in der Arktis dynamisch mit den mittleren Breiten verknüpfen. Insbesondere treten blockierende Hochdrucklagen über Skandinavien/Ural im Frühwinter und die negative Phase der Nordatlantischen Oszillation im Spätwinter häufiger auf. Daher lässt sich ableiten, dass durch eine Verbesserung der Turbulenzparametrisierung der Effekt von Meereisverlust in ECHAM6 realistischer dargestellt werden kann.
KW - boundary layer
KW - atmosphere
KW - atmospheric modelling
KW - turbulence parameterizations
KW - Atmosphäre
KW - Atmosphärenmodellierung
KW - Grenzschicht
KW - Turbulenzparametrisierungen
Y1 - 2023
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-643520
ER -
TY - JOUR
A1 - Abdalla, Hassan E.
A1 - Aharonian, Felix A.
A1 - Benkhali, F. Ait
A1 - Angüner, Ekrem Oǧuzhan
A1 - Arakawa, M.
A1 - Arcaro, C.
A1 - Armand, C.
A1 - Backes, M.
A1 - Barnard, M.
A1 - Becherini, Y.
A1 - Berge, D.
A1 - Bernloehr, K.
A1 - Blackwell, R.
A1 - Bottcher, M.
A1 - Boisson, C.
A1 - Bolmont, J.
A1 - Bonnefoy, S.
A1 - Bregeon, J.
A1 - Brun, F.
A1 - Brun, P.
A1 - Bryan, M.
A1 - Buechele, M.
A1 - Bulik, T.
A1 - Bylund, T.
A1 - Capasso, M.
A1 - Caroff, S.
A1 - Carosi, A.
A1 - Casanova, Sabrina
A1 - Cerruti, M.
A1 - Chakraborty, N.
A1 - Chand, T.
A1 - Chandra, S.
A1 - Chaves, R. C. G.
A1 - Chen, A.
A1 - Colafrancesco, S.
A1 - Condon, B.
A1 - Davids, I. D.
A1 - Deil, C.
A1 - Devin, J.
A1 - deWilt, P.
A1 - Dirson, L.
A1 - Djannati-Atai, A.
A1 - Dmytriiev, A.
A1 - Donath, A.
A1 - Doroshenko, V
A1 - Dyks, J.
A1 - Egberts, Kathrin
A1 - Emery, G.
A1 - Ernenwein, J-P
A1 - Eschbach, S.
A1 - Feijen, K.
A1 - Fegan, S.
A1 - Fiasson, A.
A1 - Fontaine, G.
A1 - Funk, S.
A1 - Fuessling, M.
A1 - Gabici, S.
A1 - Gallant, Y. A.
A1 - Gate, F.
A1 - Giavitto, G.
A1 - Glawion, D.
A1 - Glicenstein, J. F.
A1 - Gottschall, D.
A1 - Grondin, M-H
A1 - Hahn, J.
A1 - Haupt, M.
A1 - Heinzelmann, G.
A1 - Henri, G.
A1 - Hermann, G.
A1 - Hinton, James Anthony
A1 - Hofmann, W.
A1 - Hoischen, Clemens
A1 - Holch, Tim Lukas
A1 - Holler, M.
A1 - Horns, D.
A1 - Huber, D.
A1 - Iwasaki, H.
A1 - Jacholkowska, A.
A1 - Jamrozy, M.
A1 - Jankowsky, D.
A1 - Jankowsky, F.
A1 - Jouvin, L.
A1 - Jung-Richardt, I
A1 - Kastendieck, M. A.
A1 - Katarzynski, K.
A1 - Katsuragawa, M.
A1 - Katz, U.
A1 - Khangulyan, D.
A1 - Khelifi, B.
A1 - King, J.
A1 - Klepser, S.
A1 - Kluzniak, W.
A1 - Komin, Nu
A1 - Kosack, K.
A1 - Kostunin, D.
A1 - Kraus, M.
A1 - Lamanna, G.
A1 - Lau, J.
A1 - Lemiere, A.
A1 - Lemoine-Goumard, M.
A1 - Lenain, J-P
A1 - Leser, Eva
A1 - Lohse, T.
A1 - Lopez-Coto, R.
A1 - Lypova, I
A1 - Malyshev, D.
A1 - Marandon, V
A1 - Marcowith, Alexandre
A1 - Mariaud, C.
A1 - Marti-Devesa, G.
A1 - Marx, R.
A1 - Maurin, G.
A1 - Maxted, N.
A1 - Meintjes, P. J.
A1 - Mitchell, A. M. W.
A1 - Moderski, R.
A1 - Mohamed, M.
A1 - Mohrmann, L.
A1 - Moore, C.
A1 - Moulin, Emmanuel
A1 - Murach, T.
A1 - Nakashima, S.
A1 - de Naurois, M.
A1 - Ndiyavala, H.
A1 - Niederwanger, F.
A1 - Niemiec, J.
A1 - Oakes, L.
A1 - Odaka, H.
A1 - Ohm, S.
A1 - Wilhelmi, E. de Ona
A1 - Ostrowski, M.
A1 - Oya, I
A1 - Panter, M.
A1 - Parsons, R. D.
A1 - Perennes, C.
A1 - Petrucci, P-O
A1 - Peyaud, B.
A1 - Piel, Q.
A1 - Pita, S.
A1 - Poireau, V
A1 - Noel, A. Priyana
A1 - Prokhorov, D. A.
A1 - Prokoph, H.
A1 - Puehlhofer, G.
A1 - Punch, M.
A1 - Quirrenbach, A.
A1 - Raab, S.
A1 - Rauth, R.
A1 - Reimer, A.
A1 - Reimer, O.
A1 - Renaud, M.
A1 - Rieger, F.
A1 - Rinchiuso, L.
A1 - Romoli, C.
A1 - Rowell, G.
A1 - Rudak, B.
A1 - Ruiz-Velasco, E.
A1 - Sahakian, V
A1 - Saito, S.
A1 - Sanchez, David M.
A1 - Santangelo, Andrea
A1 - Sasaki, M.
A1 - Schlickeiser, R.
A1 - Schussler, F.
A1 - Schulz, A.
A1 - Schutte, H.
A1 - Schwanke, U.
A1 - Schwemmer, S.
A1 - Seglar-Arroyo, M.
A1 - Senniappan, M.
A1 - Seyffert, A. S.
A1 - Shafi, N.
A1 - Shilon, I
A1 - Shiningayamwe, K.
A1 - Simoni, R.
A1 - Sinha, A.
A1 - Sol, H.
A1 - Specovius, A.
A1 - Spir-Jacob, M.
A1 - Stawarz, L.
A1 - Steenkamp, R.
A1 - Stegmann, Christian
A1 - Steppa, Constantin Beverly
A1 - Takahashi, T.
A1 - Tavernet, J-P
A1 - Tavernier, T.
A1 - Taylor, A. M.
A1 - Terrier, R.
A1 - Tibaldo, Luigi
A1 - Tiziani, D.
A1 - Tluczykont, M.
A1 - Trichard, C.
A1 - Tsirou, M.
A1 - Tsuji, N.
A1 - Tuffs, R.
A1 - Uchiyama, Y.
A1 - van der Walt, D. J.
A1 - van Eldik, C.
A1 - van Rensburg, C.
A1 - van Soelen, B.
A1 - Vasileiadis, G.
A1 - Veh, J.
A1 - Venter, C.
A1 - Vincent, P.
A1 - Vink, J.
A1 - Voisin, F.
A1 - Voelk, H. J.
A1 - Vuillaume, T.
A1 - Wadiasingh, Z.
A1 - Wagner, S. J.
A1 - White, R.
A1 - Wierzcholska, A.
A1 - Yang, R.
A1 - Yoneda, H.
A1 - Zaborov, D.
A1 - Zacharias, M.
A1 - Zanin, R.
A1 - Zdziarski, A. A.
A1 - Zech, Alraune
A1 - Ziegler, A.
A1 - Zorn, J.
A1 - Zywucka, N.
T1 - H.E.S.S. and Suzaku observations of the Vela X pulsar wind nebula
JF - Astronomy and astrophysics : an international weekly journal
N2 - Context. Pulsar wind nebulae (PWNe) represent the most prominent population of Galactic very-high-energy gamma-ray sources and are thought to be an efficient source of leptonic cosmic rays. Vela X is a nearby middle-aged PWN, which shows bright X-ray and TeV gamma-ray emission towards an elongated structure called the cocoon. Aims. Since TeV emission is likely inverse-Compton emission of electrons, predominantly from interactions with the cosmic microwave background, while X-ray emission is synchrotron radiation of the same electrons, we aim to derive the properties of the relativistic particles and of magnetic fields with minimal modelling. Methods. We used data from the Suzaku XIS to derive the spectra from three compact regions in Vela X covering distances from 0.3 to 4 pc from the pulsar along the cocoon. We obtained gamma-ray spectra of the same regions from H.E.S.S. observations and fitted a radiative model to the multi-wavelength spectra. Results. The TeV electron spectra and magnetic field strengths are consistent within the uncertainties for the three regions, with energy densities of the order 10(-12) erg cm(-3). The data indicate the presence of a cutoff in the electron spectrum at energies of similar to 100 TeV and a magnetic field strength of similar to 6 mu G. Constraints on the presence of turbulent magnetic fields are weak. Conclusions. The pressure of TeV electrons and magnetic fields in the cocoon is dynamically negligible, requiring the presence of another dominant pressure component to balance the pulsar wind at the termination shock. Sub-TeV electrons cannot completely account for the missing pressure, which may be provided either by relativistic ions or from mixing of the ejecta with the pulsar wind. The electron spectra are consistent with expectations from transport scenarios dominated either by advection via the reverse shock or by diffusion, but for the latter the role of radiative losses near the termination shock needs to be further investigated in the light of the measured cutoff energies. Constraints on turbulent magnetic fields and the shape of the electron cutoff can be improved by spectral measurements in the energy range greater than or similar to 10 keV.
KW - stars: winds, outflows
KW - gamma rays: stars
KW - radiation mechanisms: non-thermal
KW - acceleration of particles
KW - pulsars: individual: PSR B0833-45
Y1 - 2019
U6 - https://doi.org/10.1051/0004-6361/201935458
SN - 1432-0746
VL - 627
PB - EDP Sciences
CY - Les Ulis
ER -
TY - JOUR
A1 - Abdalla, Hassan E.
A1 - Aharonian, Felix A.
A1 - Benkhali, F. Ait
A1 - Anguener, E. O.
A1 - Arakawa, M.
A1 - Arcaro, C.
A1 - Armand, C.
A1 - Ashkar, H.
A1 - Backes, M.
A1 - Martins, V. Barbosa
A1 - Barnard, M.
A1 - Becherini, Y.
A1 - Berge, D.
A1 - Bernloehr, K.
A1 - Blackwell, R.
A1 - Boettcher, M.
A1 - Boisson, C.
A1 - Bolmont, J.
A1 - Bonnefoy, S.
A1 - Bregeon, J.
A1 - Breuhaus, M.
A1 - Brun, F.
A1 - Brun, P.
A1 - Bryan, M.
A1 - Buechele, M.
A1 - Bulik, T.
A1 - Bylund, T.
A1 - Capasso, M.
A1 - Caroff, S.
A1 - Carosi, A.
A1 - Casanova, Sabrina
A1 - Cerruti, M.
A1 - Chakraborty, N.
A1 - Chand, T.
A1 - Chandra, S.
A1 - Chaves, R. C. G.
A1 - Chen, A.
A1 - Colafrancesco, S.
A1 - Curylo, M.
A1 - Davids, I. D.
A1 - Deil, C.
A1 - Devin, J.
A1 - de Wilt, P.
A1 - Dirson, L.
A1 - Djannati-Atai, A.
A1 - Dmytriiev, A.
A1 - Donath, A.
A1 - Doroshenko, V
A1 - Dyks, J.
A1 - Egberts, Kathrin
A1 - Emery, G.
A1 - Ernenwein, J-p
A1 - Eschbach, S.
A1 - Feijen, K.
A1 - Fegan, S.
A1 - Fiasson, A.
A1 - Fontaine, G.
A1 - Funk, S.
A1 - Fuessling, M.
A1 - Gabici, S.
A1 - Gallant, Y. A.
A1 - Gate, F.
A1 - Giavitto, G.
A1 - Glawion, D.
A1 - Glicenstein, J. F.
A1 - Gottschall, D.
A1 - Grondin, M-H
A1 - Hahn, J.
A1 - Haupt, M.
A1 - Heinzelmann, G.
A1 - Henri, G.
A1 - Hermann, G.
A1 - Hinton, James Anthony
A1 - Hofmann, W.
A1 - Hoischen, Clemens
A1 - Holch, Tim Lukas
A1 - Holler, M.
A1 - Horns, D.
A1 - Huber, D.
A1 - Iwasaki, H.
A1 - Jamrozy, M.
A1 - Jankowsky, D.
A1 - Jankowsky, F.
A1 - Jung-Richardt, I
A1 - Kastendieck, M. A.
A1 - Katarzynski, K.
A1 - Katsuragawa, M.
A1 - Katz, U.
A1 - Khangulyan, D.
A1 - Khelifi, B.
A1 - King, J.
A1 - Klepser, S.
A1 - Kluzniak, W.
A1 - Komin, Nu
A1 - Kosack, K.
A1 - Kostunin, D.
A1 - Kraus, M.
A1 - Lamanna, G.
A1 - Lau, J.
A1 - Lemiere, A.
A1 - Lemoine-Goumard, M.
A1 - Lenain, J-P
A1 - Leser, Eva
A1 - Levy, C.
A1 - Lohse, T.
A1 - Lopez-Coto, R.
A1 - Lypova, I
A1 - Mackey, J.
A1 - Majumdar, J.
A1 - Malyshev, D.
A1 - Marandon, V
A1 - Marcowith, Alexandre
A1 - Mares, A.
A1 - Mariaud, C.
A1 - Marti-Devesa, G.
A1 - Marx, R.
A1 - Maurin, G.
A1 - Meintjes, P. J.
A1 - Mitchell, A. M. W.
A1 - Moderski, R.
A1 - Mohamed, M.
A1 - Mohrmann, L.
A1 - Muller, J.
A1 - Moore, C.
A1 - Moulin, Emmanuel
A1 - Murach, T.
A1 - Nakashima, S.
A1 - de Naurois, M.
A1 - Ndiyavala, H.
A1 - Niederwanger, F.
A1 - Niemiec, J.
A1 - Oakes, L.
A1 - Odaka, H.
A1 - Ohm, S.
A1 - Wilhelmi, E. de Ona
A1 - Ostrowski, M.
A1 - Oya, I
A1 - Panter, M.
A1 - Parsons, R. D.
A1 - Perennes, C.
A1 - Petrucci, P-O
A1 - Peyaud, B.
A1 - Piel, Q.
A1 - Pita, S.
A1 - Poireau, V
A1 - Noel, A. Priyana
A1 - Prokhorov, D. A.
A1 - Prokoph, H.
A1 - Puehlhofer, G.
A1 - Punch, M.
A1 - Quirrenbach, A.
A1 - Raab, S.
A1 - Rauth, R.
A1 - Reimer, A.
A1 - Reimer, O.
A1 - Remy, Q.
A1 - Renaud, M.
A1 - Rieger, F.
A1 - Rinchiuso, L.
A1 - Romoli, C.
A1 - Rowell, G.
A1 - Rudak, B.
A1 - Ruiz-Velasco, E.
A1 - Sahakian, V
A1 - Saito, S.
A1 - Sanchez, David M.
A1 - Santangelo, Andrea
A1 - Sasaki, M.
A1 - Schlickeiser, R.
A1 - Schussler, F.
A1 - Schulz, A.
A1 - Schutte, H.
A1 - Schwanke, U.
A1 - Schwemmer, S.
A1 - Seglar-Arroyo, M.
A1 - Senniappan, M.
A1 - Seyffert, A. S.
A1 - Shafi, N.
A1 - Shiningayamwe, K.
A1 - Simoni, R.
A1 - Sinha, A.
A1 - Sol, H.
A1 - Specovius, A.
A1 - Spir-Jacob, M.
A1 - Stawarz, L.
A1 - Steenkamp, R.
A1 - Stegmann, Christian
A1 - Steppa, Constantin Beverly
A1 - Takahashi, T.
A1 - Tavernier, T.
A1 - Taylor, A. M.
A1 - Terrier, R.
A1 - Tiziani, D.
A1 - Tluczykont, M.
A1 - Trichard, C.
A1 - Tsirou, M.
A1 - Tsuji, N.
A1 - Tuffs, R.
A1 - Uchiyama, Y.
A1 - van der Walt, D. J.
A1 - van Eldik, C.
A1 - van Rensburg, C.
A1 - van Soelen, B.
A1 - Vasileiadis, G.
A1 - Veh, J.
A1 - Venter, C.
A1 - Vincent, P.
A1 - Vink, J.
A1 - Voisin, F.
A1 - Voelk, H. J.
A1 - Vuillaume, T.
A1 - Wadiasingh, Z.
A1 - Wagner, S. J.
A1 - White, R.
A1 - Wierzcholska, A.
A1 - Yang, R.
A1 - Yoneda, H.
A1 - Zacharias, M.
A1 - Zanin, R.
A1 - Zdziarski, A. A.
A1 - Zech, Alraune
A1 - Ziegler, A.
A1 - Zorn, J.
A1 - Zywucka, N.
A1 - Maxted, N.
T1 - Upper limits on very-high-energy gamma-ray emission from core-collapse supernovae observed with H.E.S.S.
JF - Astronomy and astrophysics : an international weekly journal
N2 - Young core-collapse supernovae with dense-wind progenitors may be able to accelerate cosmic-ray hadrons beyond the knee of the cosmic-ray spectrum, and this may result in measurable gamma-ray emission. We searched for gamma-ray emission from ten super- novae observed with the High Energy Stereoscopic System (H.E.S.S.) within a year of the supernova event. Nine supernovae were observed serendipitously in the H.E.S.S. data collected between December 2003 and December 2014, with exposure times ranging from 1.4 to 53 h. In addition we observed SN 2016adj as a target of opportunity in February 2016 for 13 h. No significant gamma-ray emission has been detected for any of the objects, and upper limits on the >1 TeV gamma-ray flux of the order of similar to 10(-13) cm(-)(2)s(-1) are established, corresponding to upper limits on the luminosities in the range similar to 2 x 10(39) to similar to 1 x 10(42) erg s(-1). These values are used to place model-dependent constraints on the mass-loss rates of the progenitor stars, implying upper limits between similar to 2 x 10(-5) and similar to 2 x 10(-3) M-circle dot yr(-1) under reasonable assumptions on the particle acceleration parameters.
KW - gamma rays: general
KW - supernovae: general
KW - cosmic rays
Y1 - 2019
U6 - https://doi.org/10.1051/0004-6361/201935242
SN - 1432-0746
VL - 626
PB - EDP Sciences
CY - Les Ulis
ER -
TY - JOUR
A1 - Abdalla, Hassan E.
A1 - Aharonian, Felix A.
A1 - Benkhali, F. Ait
A1 - Angüner, Ekrem Oǧuzhan
A1 - Arakawa, M.
A1 - Arcaro, C.
A1 - Armand, C.
A1 - Arrieta, M.
A1 - Backes, M.
A1 - Barnard, M.
A1 - Becherini, Y.
A1 - Tjus, J. Becker
A1 - Berge, D.
A1 - Bernloehr, K.
A1 - Blackwell, R.
A1 - Bottcher, M.
A1 - Boisson, C.
A1 - Bolmont, J.
A1 - Bonnefoy, S.
A1 - Bordas, Pol
A1 - Bregeon, J.
A1 - Brun, F.
A1 - Brun, P.
A1 - Bryan, M.
A1 - Buchele, M.
A1 - Bulik, T.
A1 - Bylund, T.
A1 - Capasso, M.
A1 - Caroff, S.
A1 - Carosi, A.
A1 - Casanova, Sabrina
A1 - Cerruti, M.
A1 - Chakraborty, N.
A1 - Chand, T.
A1 - Chandra, S.
A1 - Chaves, R. C. G.
A1 - Chen, A.
A1 - Colafrancesco, S.
A1 - Condon, B.
A1 - Davids, I. D.
A1 - Deil, C.
A1 - Devin, J.
A1 - deWilt, P.
A1 - Dirson, L.
A1 - Djannati-Atai, A.
A1 - Dmytriiev, A.
A1 - Donath, A.
A1 - Doroshenko, V.
A1 - Dyks, J.
A1 - Egberts, Kathrin
A1 - Emery, G.
A1 - Ernenwein, J. -P.
A1 - Eschbach, S.
A1 - Fegan, S.
A1 - Fiasson, A.
A1 - Fontaine, G.
A1 - Funk, S.
A1 - Fuessling, M.
A1 - Gabici, S.
A1 - Gallant, Y. A.
A1 - Gate, F.
A1 - Giavitto, G.
A1 - Glawion, D.
A1 - Glicenstein, J. F.
A1 - Gottschall, D.
A1 - Grondin, M. -H.
A1 - Hahn, J.
A1 - Haupt, M.
A1 - Heinzelmann, G.
A1 - Henri, G.
A1 - Hermann, G.
A1 - Hinton, James Anthony
A1 - Hofmann, W.
A1 - Hoischen, Clemens
A1 - Holch, Tim Lukas
A1 - Holler, M.
A1 - Horns, D.
A1 - Huber, D.
A1 - Iwasaki, H.
A1 - Jacholkowska, A.
A1 - Jamrozy, M.
A1 - Jankowsky, D.
A1 - Jankowsky, F.
A1 - Jouvin, L.
A1 - Jung-Richardt, I.
A1 - Kastendieck, M. A.
A1 - Katarzynski, K.
A1 - Katsuragawa, M.
A1 - Katz, U.
A1 - Khangulyan, D.
A1 - Khelifi, B.
A1 - King, J.
A1 - Klepser, S.
A1 - Kluzniak, W.
A1 - Komin, Nu.
A1 - Kosack, K.
A1 - Kraus, M.
A1 - Lamanna, G.
A1 - Lau, J.
A1 - Lefaucheur, J.
A1 - Lemiere, A.
A1 - Lemoine-Goumard, M.
A1 - Lenain, J. -P.
A1 - Leser, Eva
A1 - Lohse, T.
A1 - Lopez-Coto, R.
A1 - Lorentz, M.
A1 - Lypova, I.
A1 - Malyshev, D.
A1 - Marandon, V.
A1 - Marcowith, Alexandre
A1 - Mariaud, C.
A1 - Marti-Devesa, G.
A1 - Marx, R.
A1 - Maurin, G.
A1 - Meintjes, P. J.
A1 - Mitchell, A. M. W.
A1 - Moderski, R.
A1 - Mohamed, M.
A1 - Mohrmann, L.
A1 - Moore, C.
A1 - Moulin, Emmanuel
A1 - Murach, T.
A1 - Nakashima, S.
A1 - de Naurois, M.
A1 - Ndiyavala, H.
A1 - Niederwanger, F.
A1 - Niemiec, J.
A1 - Oakes, L.
A1 - Odaka, H.
A1 - Ohm, S.
A1 - Ostrowski, M.
A1 - Oya, I.
A1 - Panter, M.
A1 - Parsons, R. D.
A1 - Perennes, C.
A1 - Petrucci, P. -O.
A1 - Peyaud, B.
A1 - Piel, Q.
A1 - Pita, S.
A1 - Poireau, V.
A1 - Noel, A. Priyana
A1 - Prokhorov, D. A.
A1 - Prokoph, H.
A1 - Puehlhofer, G.
A1 - Punch, M.
A1 - Quirrenbach, A.
A1 - Raab, S.
A1 - Rauth, R.
A1 - Reimer, A.
A1 - Reimer, O.
A1 - Renaud, M.
A1 - Rieger, F.
A1 - Rinchiuso, L.
A1 - Romoli, C.
A1 - Rowell, G.
A1 - Rudak, B.
A1 - Ruiz-Velasco, E.
A1 - Sahakian, V.
A1 - Saito, S.
A1 - Sanchez, David M.
A1 - Santangelo, Andrea
A1 - Sasaki, M.
A1 - Schlickeiser, R.
A1 - Schussler, F.
A1 - Schulz, A.
A1 - Schutte, H.
A1 - Schwanke, U.
A1 - Schwemmer, S.
A1 - Seglar-Arroyo, M.
A1 - Senniappan, M.
A1 - Seyffert, A. S.
A1 - Shafi, N.
A1 - Shilon, I.
A1 - Shiningayamwe, K.
A1 - Simoni, R.
A1 - Sinha, A.
A1 - Sol, H.
A1 - Specovius, A.
A1 - Spir-Jacob, M.
A1 - Stawarz, L.
A1 - Steenkamp, R.
A1 - Stegmann, Christian
A1 - Steppa, Constantin Beverly
A1 - Takahashi, T.
A1 - Tavernet, J. -P.
A1 - Tavernier, T.
A1 - Taylor, A. M.
A1 - Terrier, R.
A1 - Tiziani, D.
A1 - Tluczykont, M.
A1 - Trichard, C.
A1 - Tsirou, M.
A1 - Tsuji, N.
A1 - Tuffs, R.
A1 - Uchiyama, Y.
A1 - van der Walt, D. J.
A1 - van Eldik, C.
A1 - van Rensburg, C.
A1 - van Soelen, B.
A1 - Vasileiadis, G.
A1 - Veh, J.
A1 - Venter, C.
A1 - Vincent, P.
A1 - Vink, J.
A1 - Voisin, F.
A1 - Voelk, H. J.
A1 - Vuillaume, T.
A1 - Wadiasingh, Z.
A1 - Wagner, S. J.
A1 - Wagner, R. M.
A1 - White, R.
A1 - Wierzcholska, A.
A1 - Yang, R.
A1 - Yoneda, H.
A1 - Zaborov, D.
A1 - Zacharias, M.
A1 - Zanin, R.
A1 - Zdziarski, A. A.
A1 - Zech, Alraune
A1 - Ziegler, A.
A1 - Zorn, J.
A1 - Zywucka, N.
T1 - H.E.S.S. observations of the flaring gravitationally lensed galaxy PKS 1830-211
JF - Monthly notices of the Royal Astronomical Society
N2 - PKS 1830-211 is a known macrolensed quasar located at a redshift of z = 2.5. Its highenergy gamma-ray emission has been detected with the Fermi-Large Area Telescope (LAT) instrument and evidence for lensing was obtained by several authors from its high-energy data. Observations of PKS 1830-211 were taken with the High Energy Stereoscopic System (H.E.S.S.) array of Imaging Atmospheric Cherenkov Telescopes in 2014 August, following a flare alert by the Fermi-LAT Collaboration. The H.E.S.S observations were aimed at detecting a gamma-ray flare delayed by 20-27 d from the alert flare, as expected from observations at other wavelengths. More than 12 h of good-quality data were taken with an analysis threshold of similar to 67 GeV. The significance of a potential signal is computed as a function of the date and the average significance over the whole period. Data are compared to simultaneous observations by Fermi-LAT. No photon excess or significant signal is detected. An upper limit on PKS 1830-211 flux above 67 GeV is computed and compared to the extrapolation of the Fermi-LAT flare spectrum.
KW - gravitational lensing: strong
KW - diffuse radiation
KW - gamma-rays: galaxies
Y1 - 2019
U6 - https://doi.org/10.1093/mnras/stz1031
SN - 0035-8711
SN - 1365-2966
VL - 486
IS - 3
SP - 3886
EP - 3891
PB - Oxford Univ. Press
CY - Oxford
ER -
TY - JOUR
A1 - De Angelis, A.
A1 - Tatischeff, V.
A1 - Grenier, I. A.
A1 - McEnery, J.
A1 - Mallamaci, Manuela
A1 - Tavani, M.
A1 - Oberlack, U.
A1 - Hanlon, L.
A1 - Walter, R.
A1 - Argan, A.
A1 - Von Ballmoos, P.
A1 - Bulgarelli, A.
A1 - Bykov, A.
A1 - Hernanz, M.
A1 - Kanbach, G.
A1 - Kuvvetli, I.
A1 - Pearce, M.
A1 - Zdziarski, A.
A1 - Conrad, J.
A1 - Ghisellini, G.
A1 - Harding, A.
A1 - Isern, J.
A1 - Leising, M.
A1 - Longo, F.
A1 - Madejski, G.
A1 - Martinez, M.
A1 - Mazziotta, Mario Nicola
A1 - Paredes, J. M.
A1 - Pohl, Martin
A1 - Rando, R.
A1 - Razzano, M.
A1 - Aboudan, A.
A1 - Ackermann, M.
A1 - Addazi, A.
A1 - Ajello, M.
A1 - Albertus, C.
A1 - Alvarez, J. M.
A1 - Ambrosi, G.
A1 - Anton, S.
A1 - Antonelli, L. A.
A1 - Babic, A.
A1 - Baibussinov, B.
A1 - Balbom, M.
A1 - Baldini, L.
A1 - Balman, S.
A1 - Bambi, C.
A1 - Barres de Almeida, U.
A1 - Barrio, J. A.
A1 - Bartels, R.
A1 - Bastieri, D.
A1 - Bednarek, W.
A1 - Bernard, D.
A1 - Bernardini, E.
A1 - Bernasconi, T.
A1 - Bertucci, B.
A1 - Biland, A.
A1 - Bissaldi, E.
A1 - Boettcher, M.
A1 - Bonvicini, V.
A1 - Bosch-Ramon, V.
A1 - Bottacini, E.
A1 - Bozhilov, V.
A1 - Bretz, T.
A1 - Branchesi, M.
A1 - Brdar, V.
A1 - Bringmann, T.
A1 - Brogna, A.
A1 - Jorgensen, C. Budtz
A1 - Busetto, G.
A1 - Buson, S.
A1 - Busso, M.
A1 - Caccianiga, A.
A1 - Camera, S.
A1 - Campana, R.
A1 - Caraveo, P.
A1 - Cardillo, M.
A1 - Carlson, P.
A1 - Celestin, S.
A1 - Cermeno, M.
A1 - Chen, A.
A1 - Cheung, C. C.
A1 - Churazov, E.
A1 - Ciprini, S.
A1 - Coc, A.
A1 - Colafrancesco, S.
A1 - Coleiro, A.
A1 - Collmar, W.
A1 - Coppi, P.
A1 - Curado da Silva, R.
A1 - Cutini, S.
A1 - De Lotto, B.
A1 - de Martino, D.
A1 - De Rosa, A.
A1 - Del Santo, M.
A1 - Delgado, L.
A1 - Diehl, R.
A1 - Dietrich, S.
A1 - Dolgov, A. D.
A1 - Dominguez, A.
A1 - Prester, D. Dominis
A1 - Donnarumma, I.
A1 - Dorner, D.
A1 - Doro, M.
A1 - Dutra, M.
A1 - Elsaesser, D.
A1 - Fabrizio, M.
A1 - Fernandez-Barral, A.
A1 - Fioretti, V.
A1 - Foffano, L.
A1 - Formato, V.
A1 - Fornengo, N.
A1 - Foschini, L.
A1 - Franceschini, A.
A1 - Franckowiak, A.
A1 - Funk, S.
A1 - Fuschino, F.
A1 - Gaggero, D.
A1 - Galanti, G.
A1 - Gargano, F.
A1 - Gasparrini, D.
A1 - Gehrz, R.
A1 - Giammaria, P.
A1 - Giglietto, N.
A1 - Giommi, P.
A1 - Giordano, F.
A1 - Giroletti, M.
A1 - Ghirlanda, G.
A1 - Godinovic, N.
A1 - Gouiffes, C.
A1 - Grove, J. E.
A1 - Hamadache, C.
A1 - Hartmann, D. H.
A1 - Hayashida, M.
A1 - Hryczuk, A.
A1 - Jean, P.
A1 - Johnson, T.
A1 - Jose, J.
A1 - Kaufmann, S.
A1 - Khelifi, B.
A1 - Kiener, J.
A1 - Knodlseder, J.
A1 - Kolem, M.
A1 - Kopp, J.
A1 - Kozhuharov, V.
A1 - Labanti, C.
A1 - Lalkovski, S.
A1 - Laurent, P.
A1 - Limousin, O.
A1 - Linares, M.
A1 - Lindfors, E.
A1 - Lindner, M.
A1 - Liu, J.
A1 - Lombardi, S.
A1 - Loparco, F.
A1 - Lopez-Coto, R.
A1 - Lopez Moya, M.
A1 - Lott, B.
A1 - Lubrano, P.
A1 - Malyshev, D.
A1 - Mankuzhiyil, N.
A1 - Mannheim, K.
A1 - Marcha, M. J.
A1 - Marciano, A.
A1 - Marcote, B.
A1 - Mariotti, M.
A1 - Marisaldi, M.
A1 - McBreen, S.
A1 - Mereghetti, S.
A1 - Merle, A.
A1 - Mignani, R.
A1 - Minervini, G.
A1 - Moiseev, A.
A1 - Morselli, A.
A1 - Moura, F.
A1 - Nakazawa, K.
A1 - Nava, L.
A1 - Nieto, D.
A1 - Orienti, M.
A1 - Orio, M.
A1 - Orlando, E.
A1 - Orleanski, P.
A1 - Paiano, S.
A1 - Paoletti, R.
A1 - Papitto, A.
A1 - Pasquato, M.
A1 - Patricelli, B.
A1 - Perez-Garcia, M. A.
A1 - Persic, M.
A1 - Piano, G.
A1 - Pichel, A.
A1 - Pimenta, M.
A1 - Pittori, C.
A1 - Porter, T.
A1 - Poutanen, J.
A1 - Prandini, E.
A1 - Prantzos, N.
A1 - Produit, N.
A1 - Profumo, S.
A1 - Queiroz, F. S.
A1 - Raino, S.
A1 - Raklev, A.
A1 - Regis, M.
A1 - Reichardt, I.
A1 - Rephaeli, Y.
A1 - Rico, J.
A1 - Rodejohann, W.
A1 - Fernandez, G. Rodriguez
A1 - Roncadelli, M.
A1 - Roso, L.
A1 - Rovero, A.
A1 - Ruffini, R.
A1 - Sala, G.
A1 - Sanchez-Conde, M. A.
A1 - Santangelo, Andrea
A1 - Parkinson, P. Saz
A1 - Sbarrato, T.
A1 - Shearer, A.
A1 - Shellard, R.
A1 - Short, K.
A1 - Siegert, T.
A1 - Siqueira, C.
A1 - Spinelli, P.
A1 - Stamerra, A.
A1 - Starrfield, S.
A1 - Strong, A.
A1 - Strumke, I.
A1 - Tavecchio, F.
A1 - Taverna, R.
A1 - Terzic, T.
A1 - Thompson, D. J.
A1 - Tibolla, O.
A1 - Torres, D. F.
A1 - Turolla, R.
A1 - Ulyanov, A.
A1 - Ursi, A.
A1 - Vacchi, A.
A1 - Van den Abeele, J.
A1 - Vankova-Kirilovai, G.
A1 - Venter, C.
A1 - Verrecchia, F.
A1 - Vincent, P.
A1 - Wang, X.
A1 - Weniger, C.
A1 - Wu, X.
A1 - Zaharijas, G.
A1 - Zampieri, L.
A1 - Zane, S.
A1 - Zimmer, S.
A1 - Zoglauer, A.
T1 - Science with e-ASTROGAM A space mission for MeV-GeV gamma-ray astrophysics
JF - Journal of High Energy Astrophysics
Y1 - 2018
U6 - https://doi.org/10.1016/j.jheap.2018.07.001
SN - 2214-4048
SN - 2214-4056
VL - 19
SP - 1
EP - 106
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Cheng, Xin
A1 - Zhang, Jie
A1 - Kliem, Bernhard
A1 - Török, Tibor
A1 - Xing, Chen
A1 - Zhou, Zhenjun
A1 - Inhester, Bernd
A1 - Ding, Mingde
T1 - Initiation and early kinematic evolution of solar eruptions
JF - The Astrophysical Journal
N2 - We investigate the initiation and early evolution of 12 solar eruptions, including six active-region hot channel and six quiescent filament eruptions, which were well observed by the Solar Dynamics Observatory, as well as by the Solar Terrestrial Relations Observatory for the latter. The sample includes one failed eruption and 11 coronal mass ejections, with velocities ranging from 493 to 2140 km s(-1). A detailed analysis of the eruption kinematics yields the following main results. (1) The early evolution of all events consists of a slow-rise phase followed by a main-acceleration phase, the height-time profiles of which differ markedly and can be best fit, respectively, by a linear and an exponential function. This indicates that different physical processes dominate in these phases, which is at variance with models that involve a single process. (2) The kinematic evolution of the eruptions tends to be synchronized with the flare light curve in both phases. The synchronization is often but not always close. A delayed onset of the impulsive flare phase is found in the majority of the filament eruptions (five out of six). This delay and its trend to be larger for slower eruptions favor ideal MHD instability models. (3) The average decay index at the onset heights of the main acceleration is close to the threshold of the torus instability for both groups of events (although, it is based on a tentative coronal field model for the hot channels), suggesting that this instability initiates and possibly drives the main acceleration.
KW - solar coronal mass ejections
KW - stellar coronal mass ejections
KW - solar storm
Y1 - 2020
U6 - https://doi.org/10.3847/1538-4357/ab886a
SN - 1055-6796
SN - 1476-3540
VL - 894
IS - 2
SP - 1
EP - 20
PB - Cambridge Scientific Publishers
CY - Cambridge
ER -
TY - JOUR
A1 - Herzog, Marc
A1 - Reppert, Alexander von
A1 - Pudell, Jan-Etienne
A1 - Henkel, Carsten
A1 - Kronseder, Matthias
A1 - Back, Christian H.
A1 - Maznev, Alexei A.
A1 - Bargheer, Matias
T1 - Phonon-dominated energy transport in purely metallic heterostructures
JF - Advanced functional materials
N2 - Ultrafast X-ray diffraction is used to quantify the transport of energy in laser-excited nanoscale gold-nickel (Au-Ni) bilayers.
Electron transport and efficient electron-phonon coupling in Ni convert the laser-deposited energy in the conduction electrons within a few picoseconds into a strong non-equilibrium between hot Ni and cold Au phonons at the bilayer interface.
Modeling of the subsequent equilibration dynamics within various two-temperature models confirms that for ultrathin Au films, the thermal transport is dominated by phonons instead of conduction electrons because of the weak electron-phonon coupling in Au.
KW - heterostructures
KW - nanoscale energy transports
KW - non-equilibrium
KW - thermal
KW - transports
KW - ultrafast phenomena
Y1 - 2022
U6 - https://doi.org/10.1002/adfm.202206179
SN - 1616-301X
SN - 1616-3028
VL - 32
IS - 41
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Zeuschner, Steffen Peer
A1 - Parpiiev, Tymur
A1 - Pezeril, Thomas
A1 - Hillion, Arnaud
A1 - Dumesnil, Karine
A1 - Anane, Abdelmadjid
A1 - Pudell, Jan-Etienne
A1 - Willig, Lisa
A1 - Rössle, Matthias
A1 - Herzog, Marc
A1 - Reppert, Alexander von
A1 - Bargheer, Matias
T1 - Tracking picosecond strain pulses in heterostructures that exhibit giant magnetostriction
JF - Structural Dynamics
N2 - We combine ultrafast X-ray diffraction (UXRD) and time-resolved Magneto-Optical Kerr Effect (MOKE) measurements to monitor the strain pulses in laser-excited TbFe2/Nb heterostructures. Spatial separation of the Nb detection layer from the laser excitation region allows for a background-free characterization of the laser-generated strain pulses. We clearly observe symmetric bipolar strain pulses if the excited TbFe2 surface terminates the sample and a decomposition of the strain wavepacket into an asymmetric bipolar and a unipolar pulse, if a SiO2 glass capping layer covers the excited TbFe2 layer. The inverse magnetostriction of the temporally separated unipolar strain pulses in this sample leads to a MOKE signal that linearly depends on the strain pulse amplitude measured through UXRD. Linear chain model simulations accurately predict the timing and shape of UXRD and MOKE signals that are caused by the strain reflections from multiple interfaces in the heterostructure.
KW - Heterostructures
KW - Magnetooptical effects
KW - Metal oxides
KW - Crystal lattices
KW - Transition metals
KW - Magnetism
KW - Ultrafast X-ray diffraction
KW - Lasers
KW - Bragg peak
KW - Phonons
Y1 - 2019
U6 - https://doi.org/10.1063/1.5084140
SN - 2329-7778
VL - 6
IS - 2
PB - AIP Publishing LLC
CY - Melville, NY
ER -
TY - JOUR
A1 - Reppert, Alexander von
A1 - Mattern, Maximilian
A1 - Pudell, Jan-Etienne
A1 - Zeuschner, Steffen Peer
A1 - Dumesnil, Karine
A1 - Bargheer, Matias
T1 - Unconventional picosecond strain pulses resulting from the saturation of magnetic stress within a photoexcited rare earth layer
JF - Structural Dynamics
N2 - Optical excitation of spin-ordered rare earth metals triggers a complex response of the crystal lattice since expansive stresses from electron and phonon excitations compete with a contractive stress induced by spin disorder. Using ultrafast x-ray diffraction experiments, we study the layer specific strain response of a dysprosium film within a metallic heterostructure upon femtosecond laser-excitation. The elastic and diffusive transport of energy to an adjacent, non-excited detection layer clearly separates the contributions of strain pulses and thermal excitations in the time domain. We find that energy transfer processes to magnetic excitations significantly modify the observed conventional bipolar strain wave into a unipolar pulse. By modeling the spin system as a saturable energy reservoir that generates substantial contractive stress on ultrafast timescales, we can reproduce the observed strain response and estimate the time- and space dependent magnetic stress. The saturation of the magnetic stress contribution yields a non-monotonous total stress within the nanolayer, which leads to unconventional picosecond strain pulses.
KW - Strain measurement
KW - Photoexcitations
KW - Crystal lattices
KW - Femtosecond lasers
KW - Thermal effects
KW - Heterostructures
KW - Ultrafast X-rays
KW - Phonons
Y1 - 2020
U6 - https://doi.org/10.1063/1.5145315
SN - 2329-7778
VL - 7
IS - 024303
PB - AIP Publishing LLC
CY - Melville, NY
ER -
TY - JOUR
A1 - Willig, Lisa
A1 - Reppert, Alexander von
A1 - Deb, Marwan
A1 - Ganss, F.
A1 - Hellwig, O.
A1 - Bargheer, Matias
T1 - Finite-size effects in ultrafast remagnetization dynamics of FePt
JF - Physical review : B, Condensed matter and materials physics
N2 - We investigate the ultrafast magnetization dynamics of FePt in the L1(0) phase after an optical heating pulse, as used in heat-assisted magnetic recording. We compare continuous and nano-granular thin films and emphasize the impact of the finite size on the remagnetization dynamics. The remagnetization speeds up significantly with increasing external magnetic field only for the continuous film, where domain-wall motion governs the dynamics. The ultrafast remagnetization dynamics in the continuous film are only dominated by heat transport in the regime of high magnetic fields, whereas the timescale required for cooling is prevalent in the granular film for all magnetic field strengths. These findings highlight the necessary conditions for studying the intrinsic heat transport properties in magnetic materials.
Y1 - 2019
U6 - https://doi.org/10.1103/PhysRevB.100.224408
SN - 2469-9950
SN - 2469-9969
VL - 100
IS - 22
PB - American Physical Society
CY - College Park
ER -
TY - JOUR
A1 - Cervantes Villa, Juan Sebastian
A1 - Shprits, Yuri Y.
A1 - Aseev, Nikita
A1 - Allison, Hayley J.
T1 - Quantifying the effects of EMIC wave scattering and magnetopause shadowing in the outer electron radiation belt by means of data assimilation
JF - Journal of geophysical research : Space physics
N2 - In this study we investigate two distinct loss mechanisms responsible for the rapid dropouts of radiation belt electrons by assimilating data from Van Allen Probes A and B and Geostationary Operational Environmental Satellites (GOES) 13 and 15 into a 3-D diffusion model. In particular, we examine the respective contribution of electromagnetic ion cyclotron (EMIC) wave scattering and magnetopause shadowing for values of the first adiabatic invariant mu ranging from 300 to 3,000 MeV G(-1). We inspect the innovation vector and perform a statistical analysis to quantitatively assess the effect of both processes as a function of various geomagnetic indices, solar wind parameters, and radial distance from the Earth. Our results are in agreement with previous studies that demonstrated the energy dependence of these two mechanisms. We show that EMIC wave scattering tends to dominate loss at lower L shells, and it may amount to between 10%/hr and 30%/hr of the maximum value of phase space density (PSD) over all L shells for fixed first and second adiabatic invariants. On the other hand, magnetopause shadowing is found to deplete electrons across all energies, mostly at higher L shells, resulting in loss from 50%/hr to 70%/hr of the maximum PSD. Nevertheless, during times of enhanced geomagnetic activity, both processes can operate beyond such location and encompass the entire outer radiation belt.
Y1 - 2020
U6 - https://doi.org/10.1029/2020JA028208
SN - 2169-9380
SN - 2169-9402
VL - 125
IS - 8
PB - American Geophysical Union
CY - Washington
ER -
TY - JOUR
A1 - Warby, Jonathan
A1 - Zu, Fengshuo
A1 - Zeiske, Stefan
A1 - Gutierrez-Partida, Emilio
A1 - Frohloff, Lennart
A1 - Kahmann, Simon
A1 - Frohna, Kyle
A1 - Mosconi, Edoardo
A1 - Radicchi, Eros
A1 - Lang, Felix
A1 - Shah, Sahil
A1 - Pena-Camargo, Francisco
A1 - Hempel, Hannes
A1 - Unold, Thomas
A1 - Koch, Norbert
A1 - Armin, Ardalan
A1 - De Angelis, Filippo
A1 - Stranks, Samuel D.
A1 - Neher, Dieter
A1 - Stolterfoht, Martin
T1 - Understanding performance limiting interfacial recombination in pin Perovskite solar cells
JF - Advanced energy materials
N2 - Perovskite semiconductors are an attractive option to overcome the limitations of established silicon based photovoltaic (PV) technologies due to their exceptional opto-electronic properties and their successful integration into multijunction cells. However, the performance of single- and multijunction cells is largely limited by significant nonradiative recombination at the perovskite/organic electron transport layer junctions. In this work, the cause of interfacial recombination at the perovskite/C-60 interface is revealed via a combination of photoluminescence, photoelectron spectroscopy, and first-principle numerical simulations. It is found that the most significant contribution to the total C-60-induced recombination loss occurs within the first monolayer of C-60, rather than in the bulk of C-60 or at the perovskite surface. The experiments show that the C-60 molecules act as deep trap states when in direct contact with the perovskite. It is further demonstrated that by reducing the surface coverage of C-60, the radiative efficiency of the bare perovskite layer can be retained. The findings of this work pave the way toward overcoming one of the most critical remaining performance losses in perovskite solar cells.
KW - C60
KW - defects
KW - interface recombination
KW - loss mechanisms
KW - perovskites
KW - solar cells
Y1 - 2022
U6 - https://doi.org/10.1002/aenm.202103567
SN - 1614-6832
SN - 1614-6840
VL - 12
IS - 12
PB - Wiley-VCH
CY - Weinheim
ER -
TY - JOUR
A1 - Abdalla, Hassan E.
A1 - Adam, R.
A1 - Aharonian, Felix A.
A1 - Benkhali, F. Ait
A1 - Angüner, Ekrem Oǧuzhan
A1 - Arakawa, M.
A1 - Arcaro, C.
A1 - Armand, C.
A1 - Ashkar, H.
A1 - Backes, M.
A1 - Martins, V. Barbosa
A1 - Barnard, M.
A1 - Becherini, Y.
A1 - Berge, D.
A1 - Bernloehr, K.
A1 - Blackwell, R.
A1 - Böttcher, M.
A1 - Boisson, C.
A1 - Bolmont, J.
A1 - Bonnefoy, S.
A1 - Bregeon, J.
A1 - Breuhaus, M.
A1 - Brun, F.
A1 - Brun, P.
A1 - Bryan, M.
A1 - Büchele, M.
A1 - Bulik, T.
A1 - Bylund, T.
A1 - Capasso, M.
A1 - Caroff, S.
A1 - Carosi, A.
A1 - Casanova, Sabrina
A1 - Cerruti, M.
A1 - Chand, T.
A1 - Chandra, S.
A1 - Chen, A.
A1 - Colafrancesco, S.
A1 - Curylo, M.
A1 - Davids, I. D.
A1 - Deil, C.
A1 - Devin, J.
A1 - DeWilt, P.
A1 - Dirson, L.
A1 - Djannati-Ata, A.
A1 - Dmytriiev, A.
A1 - Donath, A.
A1 - Doroshenko, V
A1 - Dyks, J.
A1 - Egberts, Kathrin
A1 - Emery, G.
A1 - Ernenwein, J-P
A1 - Eschbach, S.
A1 - Feijen, K.
A1 - Fegan, S.
A1 - Fiasson, A.
A1 - Fontaine, G.
A1 - Funk, S.
A1 - Füßling, Matthias
A1 - Gabici, S.
A1 - Gallant, Y. A.
A1 - Gate, F.
A1 - Giavitto, G.
A1 - Glawion, D.
A1 - Glicenstein, J. F.
A1 - Gottschall, D.
A1 - Grondin, M-H
A1 - Hahn, J.
A1 - Haupt, M.
A1 - Heinzelmann, G.
A1 - Henri, G.
A1 - Hermann, G.
A1 - Hinton, James Anthony
A1 - Hofmann, W.
A1 - Hoischen, Clemens
A1 - Holch, Tim Lukas
A1 - Holler, M.
A1 - Horns, D.
A1 - Huber, D.
A1 - Iwasaki, H.
A1 - Jamrozy, M.
A1 - Jankowsky, D.
A1 - Jankowsky, F.
A1 - Jardin-Blicq, A.
A1 - Jung-Richardt, I
A1 - Kastendieck, M. A.
A1 - Katarzynski, K.
A1 - Katsuragawa, M.
A1 - Katz, U.
A1 - Khangulyan, D.
A1 - Khelifi, B.
A1 - King, J.
A1 - Klepser, S.
A1 - Kluzniak, W.
A1 - Komin, Nu
A1 - Kosack, K.
A1 - Kostunin, D.
A1 - Kraus, M.
A1 - Lamanna, G.
A1 - Lau, J.
A1 - Lemiere, A.
A1 - Lemoine-Goumard, M.
A1 - Lenain, J-P
A1 - Leser, Eva
A1 - Levy, C.
A1 - Lohse, T.
A1 - Lypova, I
A1 - Mackey, J.
A1 - Majumdar, J.
A1 - Malyshev, D.
A1 - Marandon, V
A1 - Marcowith, Alexandre
A1 - Mares, A.
A1 - Mariaud, C.
A1 - Marti-Devesa, G.
A1 - Marx, R.
A1 - Maurin, G.
A1 - Meintjes, P. J.
A1 - Mitchell, A. M. W.
A1 - Moderski, R.
A1 - Mohamed, M.
A1 - Mohrmann, L.
A1 - Moore, C.
A1 - Moulin, Emmanuel
A1 - Muller, J.
A1 - Murach, T.
A1 - Nakashima, S.
A1 - de Naurois, M.
A1 - Ndiyavala, H.
A1 - Niederwanger, F.
A1 - Niemiec, J.
A1 - Oakes, L.
A1 - Odaka, H.
A1 - Ohm, S.
A1 - Wilhelmi, E. de Ona
A1 - Ostrowski, M.
A1 - Oya, I
A1 - Panter, M.
A1 - Parsons, R. D.
A1 - Perennes, C.
A1 - Petrucci, P-O
A1 - Peyaud, B.
A1 - Piel, Q.
A1 - Pita, S.
A1 - Poireau, V
A1 - Priyana Noel, A.
A1 - Prokhorov, D. A.
A1 - Prokoph, H.
A1 - Pühlhofer, G.
A1 - Punch, M.
A1 - Quirrenbach, A.
A1 - Raab, S.
A1 - Rauth, R.
A1 - Reimer, A.
A1 - Reimer, O.
A1 - Remy, Q.
A1 - Renaud, M.
A1 - Rieger, F.
A1 - Rinchiuso, L.
A1 - Romoli, C.
A1 - Rowell, G.
A1 - Rudak, B.
A1 - Ruiz-Velasco, E.
A1 - Sahakian, V
A1 - Saito, S.
A1 - Sanchez, David M.
A1 - Santangelo, Andrea
A1 - Sasaki, M.
A1 - Schlickeiser, R.
A1 - Schüssler, F.
A1 - Schulz, A.
A1 - Schutte, H.
A1 - Schwanke, U.
A1 - Schwemmer, S.
A1 - Seglar-Arroyo, M.
A1 - Senniappan, M.
A1 - Seyffert, A. S.
A1 - Shafi, N.
A1 - Shiningayamwe, K.
A1 - Simoni, R.
A1 - Sinha, A.
A1 - Sol, H.
A1 - Specovius, A.
A1 - Spir-Jacob, M.
A1 - Stawarz, L.
A1 - Steenkamp, R.
A1 - Stegmann, Christian
A1 - Steppa, Constantin Beverly
A1 - Takahashi, T.
A1 - Tavernier, T.
A1 - Taylor, A. M.
A1 - Terrier, R.
A1 - Tiziani, D.
A1 - Tluczykont, M.
A1 - Trichard, C.
A1 - Tsirou, M.
A1 - Tsuji, N.
A1 - Tuffs, R.
A1 - Uchiyama, Y.
A1 - van Der Walt, D. J.
A1 - van Eldik, C.
A1 - van Rensburg, C.
A1 - van Soelen, B.
A1 - Vasileiadis, G.
A1 - Veh, J.
A1 - Venter, C.
A1 - Vincent, P.
A1 - Vink, J.
A1 - Voisin, F.
A1 - Voelk, H. J.
A1 - Vuillaume, T.
A1 - Wadiasingh, Z.
A1 - Wagner, S. J.
A1 - White, R.
A1 - Wierzcholska, A.
A1 - Yang, R.
A1 - Yoneda, H.
A1 - Zacharias, Michael
A1 - Zanin, R.
A1 - Zdziarski, A. A.
A1 - Zech, Alraune
A1 - Ziegler, A.
A1 - Zorn, J.
A1 - Zywucka, N.
A1 - Meyer, M.
T1 - Constraints on the emission region of 3C 279 during strong flares in 2014 and 2015 through VHE gamma-ray observations with HESS
JF - Astronomy and astrophysics : an international weekly journal
N2 - The flat spectrum radio quasar 3C 279 is known to exhibit pronounced variability in the high-energy (100MeV < E < 100 GeV) gamma-ray band, which is continuously monitored with Fermi-LAT. During two periods of high activity in April 2014 and June 2015 target-of-opportunity observations were undertaken with the High Energy Stereoscopic System (H.E.S.S.) in the very-high-energy (VHE, E > 100 GeV) gamma-ray domain. While the observation in 2014 provides an upper limit, the observation in 2015 results in a signal with 8 : 7 sigma significance above an energy threshold of 66 GeV. No VHE variability was detected during the 2015 observations. The VHE photon spectrum is soft and described by a power-law index of 4.2 +/- 0.3. The H.E.S.S. data along with a detailed and contemporaneous multiwavelength data set provide constraints on the physical parameters of the emission region. The minimum distance of the emission region from the central black hole was estimated using two plausible geometries of the broad-line region and three potential intrinsic spectra. The emission region is confidently placed at r greater than or similar to 1 : 7 X 1017 cm from the black hole, that is beyond the assumed distance of the broad-line region. Time-dependent leptonic and lepto-hadronic one-zone models were used to describe the evolution of the 2015 flare. Neither model can fully reproduce the observations, despite testing various parameter sets. Furthermore, the H.E.S.S. data were used to derive constraints on Lorentz invariance violation given the large redshift of 3C 279.
KW - radiation mechanisms: non-thermal
KW - quasars: individual: 3C 279
KW - galaxies: active
KW - relativistic processes
Y1 - 2019
U6 - https://doi.org/10.1051/0004-6361/201935704
SN - 1432-0746
VL - 627
PB - EDP Sciences
CY - Les Ulis
ER -
TY - JOUR
A1 - Abdalla, Hassan E.
A1 - Collaboration, H. E. S. S.
A1 - Abramowski, A.
A1 - Aharonian, Felix A.
A1 - Benkhali, F. Ait
A1 - Angüner, Ekrem Oǧuzhan
A1 - Arakawa, M.
A1 - Armand, C.
A1 - Arrieta, M.
A1 - Backes, M.
A1 - Balzer, A.
A1 - Barnard, M.
A1 - Becherini, Y.
A1 - Tjus, J. Becker
A1 - Berge, D.
A1 - Bernhard, S.
A1 - Bernloehr, K.
A1 - Blackwell, R.
A1 - Bottcher, M.
A1 - Boisson, C.
A1 - Bolmont, J.
A1 - Bonnefoy, S.
A1 - Bordas, Pol
A1 - Bregeon, J.
A1 - Brun, F.
A1 - Brun, P.
A1 - Bryan, M.
A1 - Buechele, M.
A1 - Bulik, T.
A1 - Capasso, M.
A1 - Caroff, S.
A1 - Carosi, A.
A1 - Casanova, Sabrina
A1 - Cerruti, M.
A1 - Chakraborty, N.
A1 - Chaves, R. C. G.
A1 - Chen, A.
A1 - Chevalier, J.
A1 - Colafrancesco, S.
A1 - Condon, B.
A1 - Conrad, J.
A1 - Davids, I. D.
A1 - Decock, J.
A1 - Deil, C.
A1 - Devin, J.
A1 - deWilt, P.
A1 - Dirson, L.
A1 - Djannati-Atai, A.
A1 - Donath, A.
A1 - Dyks, J.
A1 - Edwards, T.
A1 - Egberts, Kathrin
A1 - Emery, G.
A1 - Ernenwein, J. -P.
A1 - Eschbach, S.
A1 - Farnier, C.
A1 - Fegan, S.
A1 - Fernandes, M. V.
A1 - Fiasson, A.
A1 - Fontaine, G.
A1 - Funk, S.
A1 - Fuessling, M.
A1 - Gabici, S.
A1 - Gallant, Y. A.
A1 - Garrigoux, T.
A1 - Gate, F.
A1 - Giavitto, G.
A1 - Glawion, D.
A1 - Glicenstein, J. F.
A1 - Gottschall, D.
A1 - Grondin, M. -H.
A1 - Hahn, J.
A1 - Haupt, M.
A1 - Hawkes, J.
A1 - Heinzelmann, G.
A1 - Henri, G.
A1 - Hermann, G.
A1 - Hinton, J. A.
A1 - Hofmann, W.
A1 - Hoischen, Clemens
A1 - Holch, T. L.
A1 - Holler, M.
A1 - Horns, D.
A1 - Ivascenko, A.
A1 - Iwasaki, H.
A1 - Jacholkowska, A.
A1 - Jamrozy, M.
A1 - Jankowsky, D.
A1 - Jankowsky, F.
A1 - Jingo, M.
A1 - Jouvin, L.
A1 - Jung-Richardt, I.
A1 - Kastendieck, M. A.
A1 - Katarzynski, K.
A1 - Katsuragawa, M.
A1 - Katz, U.
A1 - Kerszberg, D.
A1 - Khangulyan, D.
A1 - Khelifi, B.
A1 - King, J.
A1 - Klepser, S.
A1 - Klochkov, D.
A1 - Kluzniak, W.
A1 - Komin, Nu.
A1 - Kosack, K.
A1 - Krakau, S.
A1 - Kraus, M.
A1 - Kruger, P. P.
A1 - Laffon, H.
A1 - Lamanna, G.
A1 - Lau, J.
A1 - Lefaucheur, J.
A1 - Lemiere, A.
A1 - Lemoine-Goumard, M.
A1 - Lenain, J. -P.
A1 - Leser, Eva
A1 - Lohse, T.
A1 - Lorentz, M.
A1 - Liu, R.
A1 - Lopez-Coto, R.
A1 - Lypova, I.
A1 - Malyshev, D.
A1 - Marandon, V.
A1 - Marcowith, Alexandre
A1 - Mariaud, C.
A1 - Marx, R.
A1 - Maurin, G.
A1 - Maxted, N.
A1 - Mayer, M.
A1 - Meintjes, P. J.
A1 - Meyer, M.
A1 - Mitchell, A. M. W.
A1 - Moderski, R.
A1 - Mohamed, M.
A1 - Mohrmann, L.
A1 - Mora, K.
A1 - Moulin, Emmanuel
A1 - Murach, T.
A1 - Nakashima, S.
A1 - de Naurois, M.
A1 - Ndiyavala, H.
A1 - Niederwanger, F.
A1 - Niemiec, J.
A1 - Oakes, L.
A1 - Odaka, H.
A1 - Ohm, S.
A1 - Ostrowski, M.
A1 - Oya, I.
A1 - Padovani, M.
A1 - Panter, M.
A1 - Parsons, R. D.
A1 - Pekeur, N. W.
A1 - Pelletier, G.
A1 - Perennes, C.
A1 - Petrucci, P. -O.
A1 - Peyaud, B.
A1 - Piel, Q.
A1 - Pita, S.
A1 - Poireau, V.
A1 - Prokhorov, D. A.
A1 - Prokoph, H.
A1 - Puehlhofer, G.
A1 - Punch, M.
A1 - Quirrenbach, A.
A1 - Raab, S.
A1 - Rauth, R.
A1 - Reimer, A.
A1 - Reimer, O.
A1 - Renaud, M.
A1 - de los Reyes, R.
A1 - Rieger, F.
A1 - Rinchiuso, L.
A1 - Romoli, C.
A1 - Rowell, G.
A1 - Rudak, B.
A1 - Rulten, C. B.
A1 - Sahakian, V.
A1 - Saito, S.
A1 - Sanchez, D. A.
A1 - Santangelo, Andrea
A1 - Sasaki, M.
A1 - Schlickeiser, R.
A1 - Schussler, F.
A1 - Schulz, A.
A1 - Schwanke, U.
A1 - Schwemmer, S.
A1 - Seglar-Arroyo, M.
A1 - Seyffert, A. S.
A1 - Shafi, N.
A1 - Shilon, I.
A1 - Shiningayamwe, K.
A1 - Simoni, R.
A1 - Sol, H.
A1 - Spanier, F.
A1 - Spir-Jacob, M.
A1 - Stawarz, L.
A1 - Steenkamp, R.
A1 - Stegmann, Christian
A1 - Steppa, Constantin Beverly
A1 - Sushch, I.
A1 - Takahashi, T.
A1 - Tavernet, J. -P.
A1 - Tavernier, T.
A1 - Taylor, A. M.
A1 - Terrier, R.
A1 - Tibaldo, L.
A1 - Tiziani, D.
A1 - Tluczykont, M.
A1 - Trichard, C.
A1 - Tsirou, M.
A1 - Tsuji, N.
A1 - Tuffs, R.
A1 - Uchiyama, Y.
A1 - van der Walt, D. J.
A1 - van Eldik, C.
A1 - van Rensburg, C.
A1 - van Soelen, B.
A1 - Vasileiadis, G.
A1 - Veh, J.
A1 - Venter, C.
A1 - Viana, A.
A1 - Vincent, P.
A1 - Vink, J.
A1 - Voisin, F.
A1 - Voelk, H. J.
A1 - Vuillaume, T.
A1 - Wadiasingh, Z.
A1 - Wagner, S. J.
A1 - Wagner, P.
A1 - Wagner, R. M.
A1 - White, R.
A1 - Wierzcholska, A.
A1 - Willmann, P.
A1 - Woernlein, A.
A1 - Wouters, D.
A1 - Yang, R.
A1 - Zaborov, D.
A1 - Zacharias, M.
A1 - Zanin, R.
A1 - Zdziarski, A. A.
A1 - Zech, Alraune
A1 - Zefi, F.
A1 - Ziegler, A.
A1 - Zorn, J.
A1 - Zywucka, N.
T1 - Detection of variable VHE gamma-ray emission from the extra-galactic gamma-ray binary LMC P3
JF - Astronomy and astrophysics : an international weekly journal
N2 - Context. Recently, the high-energy (HE, 0.1-100 GeV) gamma-ray emission from the object LMC P3 in the Large Magellanic Cloud (LMC) has been discovered to be modulated with a 10.3-day period, making it the first extra-galactic gamma-ray binary. Aims. This work aims at the detection of very-high-energy (VHE, >100 GeV) gamma-ray emission and the search for modulation of the VHE signal with the orbital period of the binary system. Methods. LMC P3 has been observed with the High Energy Stereoscopic System (H.E.S.S.); the acceptance-corrected exposure time is 100 h. The data set has been folded with the known orbital period of the system in order to test for variability of the emission. Results. VHE gamma-ray emission is detected with a statistical significance of 6.4 sigma. The data clearly show variability which is phase-locked to the orbital period of the system. Periodicity cannot be deduced from the H.E.S.S. data set alone. The orbit-averaged luminosity in the 1-10 TeV energy range is (1.4 +/- 0.2) x 10(35) erg s(-1). A luminosity of (5 +/- 1) x 10(35) erg s(-1) is reached during 20% of the orbit. HE and VHE gamma-ray emissions are anti-correlated. LMC P3 is the most luminous gamma-ray binary known so far.
KW - gamma rays: stars
KW - binaries: general
KW - stars: massive
Y1 - 2018
U6 - https://doi.org/10.1051/0004-6361/201732426
SN - 1432-0746
VL - 610
PB - EDP Sciences
CY - Les Ulis
ER -
TY - JOUR
A1 - Schwope, Axel
A1 - Pires, Adriana M.
A1 - Kurpas, Jan
A1 - Doroshenko, Victor
A1 - Suleimanov, Valery F.
A1 - Freyberg, Michael
A1 - Becker, Werner
A1 - Dennerl, Konrad
A1 - Haberl, Frank
A1 - Lamer, Georg
A1 - Maitra, Chandreyee
A1 - Potekhin, Alexander Y.
A1 - Ramos-Ceja, Miriam E.
A1 - Santangelo, Andrea
A1 - Traulsen, Iris
A1 - Werner, Klaus
T1 - Phase-resolved X-ray spectroscopy of PSR B0656+14 with SRG/eROSITA and XMM-Newton
JF - Astronomy and astrophysics : an international weekly journal
N2 - We present a detailed spectroscopic and timing analysis of X-ray observations of the bright pulsar PSR B0656+14. The observations were obtained simultaneously with eROSITA and XMM-Newton during the calibration and performance verification phase of the Spektrum-Roentgen-Gamma mission (SRG). The analysis of the 100 ks deep observation of eROSITA is supported by archival observations of the source, including XMM-Newton, NuSTAR, and NICER. Using XMM-Newton and NICER, we first established an X-ray ephemeris for the time interval 2015 to 2020, which connects all X-ray observations in this period without cycle count alias and phase shifts. The mean eROSITA spectrum clearly reveals an absorption feature originating from the star at 570 eV with a Gaussian sigma of about 70 eV that was tentatively identified in a previous long XMM-Newton observation. A second previously discussed absorption feature occurs at 260-265 eV and is described here as an absorption edge. It could be of atmospheric or of instrumental origin. These absorption features are superposed on various emission components that are phenomenologically described here as the sum of hot (120 eV) and cold (65 eV) blackbody components, both of photospheric origin, and a power law with photon index Gamma = 2 from the magnetosphere. We created energy-dependent light curves and phase-resolved spectra with a high signal-to-noise ratio. The phase-resolved spectroscopy reveals that the Gaussian absorption line at 570 eV is clearly present throughout similar to 60% of the spin cycle, but it is otherwise undetected. Likewise, its parameters were found to be dependent on phase. The visibility of the line strength coincides in phase with the maximum flux of the hot blackbody. If the line originates from the stellar surface, it nevertheless likely originates from a different location than the hot polar cap. We also present three families of model atmospheres: a magnetized atmosphere, a condensed surface, and a mixed model. They were applied to the mean observed spectrum, whose continuum fit the observed data well. The atmosphere model, however, predicts distances that are too short. For the mixed model, the Gaussian absorption may be interpreted as proton cyclotron absorption in a field as high as 10(14) G, which is significantly higher than the field derived from the moderate observed spin-down.
KW - stars: neutron
KW - X-rays: stars
KW - pulsars: individual: PSR B0656+14
Y1 - 2022
U6 - https://doi.org/10.1051/0004-6361/202141105
SN - 0004-6361
SN - 1432-0746
VL - 661
PB - EDP Sciences
CY - Les Ulis
ER -
TY - JOUR
A1 - Ye, Fangyuan
A1 - Zhang, Shuo
A1 - Warby, Jonathan
A1 - Wu, Jiawei
A1 - Gutierrez-Partida, Emilio
A1 - Lang, Felix
A1 - Shah, Sahil
A1 - Saglamkaya, Elifnaz
A1 - Sun, Bowen
A1 - Zu, Fengshuo
A1 - Shoai, Safa
A1 - Wang, Haifeng
A1 - Stiller, Burkhard
A1 - Neher, Dieter
A1 - Zhu, Wei-Hong
A1 - Stolterfoht, Martin
A1 - Wu, Yongzhen
T1 - Overcoming C₆₀-induced interfacial recombination in inverted perovskite solar cells by electron-transporting carborane
JF - Nature Communications
N2 - Inverted perovskite solar cells still suffer from significant non-radiative recombination losses at the perovskite surface and across the perovskite/C₆₀ interface, limiting the future development of perovskite-based single- and multi-junction photovoltaics. Therefore, more effective inter- or transport layers are urgently required. To tackle these recombination losses, we introduce ortho-carborane as an interlayer material that has a spherical molecular structure and a three-dimensional aromaticity. Based on a variety of experimental techniques, we show that ortho-carborane decorated with phenylamino groups effectively passivates the perovskite surface and essentially eliminates the non-radiative recombination loss across the perovskite/C₆₀ interface with high thermal stability. We further demonstrate the potential of carborane as an electron transport material, facilitating electron extraction while blocking holes from the interface. The resulting inverted perovskite solar cells deliver a power conversion efficiency of over 23% with a low non-radiative voltage loss of 110 mV, and retain >97% of the initial efficiency after 400 h of maximum power point tracking. Overall, the designed carborane based interlayer simultaneously enables passivation, electron-transport and hole-blocking and paves the way toward more efficient and stable perovskite solar cells.
Y1 - 2022
U6 - https://doi.org/10.1038/s41467-022-34203-x
SN - 2041-1723
VL - 13
IS - 1
PB - Springer Nature
CY - London
ER -
TY - JOUR
A1 - Kupfer, Thomas
A1 - Bauer, Evan B.
A1 - van Roestel, Jan
A1 - Bellm, Eric C.
A1 - Bildsten, Lars
A1 - Fuller, Jim
A1 - Prince, Thomas A.
A1 - Heber, Ulrich
A1 - Geier, Stephan
A1 - Green, Matthew J.
A1 - Kulkarni, Shrinivas R.
A1 - Bloemen, Steven
A1 - Laher, Russ R.
A1 - Rusholme, Ben
A1 - Schneider, David
T1 - Discovery of a Double-detonation Thermonuclear Supernova Progenitor
JF - The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters
N2 - We present the discovery of a new double-detonation progenitor system consisting of a hot subdwarf B (sdB) binary with a white dwarf companion with a P (orb) = 76.34179(2) minutes orbital period. Spectroscopic observations are consistent with an sdB star during helium core burning residing on the extreme horizontal branch. Chimera light curves are dominated by ellipsoidal deformation of the sdB star and a weak eclipse of the companion white dwarf. Combining spectroscopic and light curve fits, we find a low-mass sdB star, M (sdB) = 0.383 +/- 0.028 M (circle dot) with a massive white dwarf companion, M (WD) = 0.725 +/- 0.026 M (circle dot). From the eclipses we find a blackbody temperature for the white dwarf of 26,800 K resulting in a cooling age of approximate to 25 Myr whereas our MESA model predicts an sdB age of approximate to 170 Myr. We conclude that the sdB formed first through stable mass transfer followed by a common envelope which led to the formation of the white dwarf companion approximate to 25 Myr ago. Using the MESA stellar evolutionary code we find that the sdB star will start mass transfer in approximate to 6 Myr and in approximate to 60 Myr the white dwarf will reach a total mass of 0.92 M (circle dot) with a thick helium layer of 0.17 M (circle dot). This will lead to a detonation that will likely destroy the white dwarf in a peculiar thermonuclear supernova. PTF1 J2238+7430 is only the second confirmed candidate for a double-detonation thermonuclear supernova. Using both systems we estimate that at least approximate to 1% of white dwarf thermonuclear supernovae originate from sdB+WD binaries with thick helium layers, consistent with the small number of observed peculiar thermonuclear explosions.
Y1 - 2022
U6 - https://doi.org/10.3847/2041-8213/ac48f1
SN - 2041-8205
SN - 2041-8213
VL - 925
IS - 2
PB - IOP Publ. Ltd.
CY - Bristol
ER -
TY - JOUR
A1 - Schaffenroth, Veronika
A1 - Casewell, Sarah L.
A1 - Schneider, D.
A1 - Kilkenny, David
A1 - Geier, Stephan
A1 - Heber, Ulrich
A1 - Irrgang, Andreas
A1 - Przybilla, Norbert
A1 - Marsh, Thomas R.
A1 - Littlefair, Stuart P.
A1 - Dhillon, Vik S.
T1 - A quantitative in-depth analysis of the prototype sdB plus BD system SDSS J08205+0008 revisited in the Gaia era
JF - Monthly notices of the Royal Astronomical Society
N2 - Subdwarf B stars are core-helium-burning stars located on the extreme horizontal branch (EHB). Extensive mass loss on the red giant branch is necessary to form them. It has been proposed that substellar companions could lead to the required mass loss when they are engulfed in the envelope of the red giant star. J08205+0008 was the first example of a hot subdwarf star with a close, substellar companion candidate to be found. Here, we perform an in-depth re-analysis of this important system with much higher quality data allowing additional analysis methods. From the higher resolution spectra obtained with ESO-VLT/XSHOOTER, we derive the chemical abundances of the hot subdwarf as well as its rotational velocity. Using the Gaia parallax and a fit to the spectral energy distribution in the secondary eclipse, tight constraints to the radius of the hot subdwarf are derived. From a long-term photometric campaign, we detected a significant period decrease of -3.2(8) x 10(-12) dd(-1). This can be explained by the non-synchronized hot subdwarf star being spun up by tidal interactions forcing it to become synchronized. From the rate of period decrease we could derive the synchronization time-scale to be 4 Myr, much smaller than the lifetime on EHB. By combining all different methods, we could constrain the hot subdwarf to a mass of 0.39-0.50 M-circle dot and a radius of R-sdB = 0.194 +/- 0.008 R-circle dot, and the companion to 0.061-0.071 M-circle dot with a radius of R-comp = 0.092 +/- 0.005 R-circle dot, below the hydrogen-burning limit. We therefore confirm that the companion is most likely a massive brown dwarf.
KW - stars: abundances
KW - stars: atmospheres
KW - stars: fundamental parameters
KW - stars: horizontal branch
KW - stars: low-mass
KW - subdwarfs
Y1 - 2020
U6 - https://doi.org/10.1093/mnras/staa3661
SN - 0035-8711
SN - 1365-2966
VL - 501
IS - 3
SP - 3847
EP - 3870
PB - Oxford Univ. Press
CY - Oxford
ER -
TY - JOUR
A1 - Köhler, Raphael H.
A1 - Handorf, Dörthe
A1 - Jaiser, Ralf
A1 - Dethloff, Klaus
A1 - Zängl, Günther
A1 - Majewski, Detlev
A1 - Rex, Markus
T1 - Improved circulation in the Northern hemisphere by adjusting gravity wave drag parameterizations in seasonal experiments with ICON-NWP
JF - Earth and Space Science : ESS
N2 - The stratosphere is one of the main potential sources for subseasonal to seasonal predictability in midlatitudes in winter. The ability of an atmospheric model to realistically simulate the stratospheric dynamics is essential in order to move forward in the field of seasonal predictions in midlatitudes. Earlier studies with the ICOsahedral Nonhydrostatic atmospheric model (ICON) point out that stratospheric westerlies in ICON are underestimated. This is the first extensive study on the evaluation of Northern Hemisphere stratospheric winter circulation with ICON in numerical weather prediction (NWP) mode. Seasonal experiments with the default setup are able to reproduce the basic climatology of the stratospheric polar vortex. However, westerlies are too weak and major stratospheric warmings too frequent in ICON. Both a reduction of the nonorographic, and a reduction of the orographic gravity wave and wake drag lead to a strengthening of the stratospheric vortex and a bias reduction, in particular in January. However, the effect of the nonorographic gravity wave drag scheme on the stratosphere is stronger. Stratosphere-troposphere coupling is intensified and more realistic due to a reduced gravity wave drag. Furthermore, an adjustment of the subgrid-scale orographic drag parameterization leads to a significant error reduction in the mean sea level pressure. As a result of these findings, we present our current suggested improved setup for seasonal experiments with ICON-NWP.
Plain Language Summary Although seasonal forecasts for midlatitudes have the potential to be highly beneficial to the public sector, they are still characterized by a large amount of uncertainty. Exact simulations of the circulation in the stratosphere can help to improve tropospheric predictability on seasonal time scales. For this reason, we investigate how well the new German atmospheric model is able to simulate the stratospheric circulation. The model reproduces the basic behavior of the Northern Hemisphere stratospheric polar vortex, but the westerly circulation in winter is underestimated. The stratospheric circulation is influenced by gravity waves that exert drag on the flow. These processes are only partly physically represented in the model, but are very important and are hence parameterized. By adjusting the parameterizations for the gravity wave drag, the stratospheric polar vortex is strengthened, thereby yielding a more realistic stratospheric circulation. In addition, the altered parameterizations improve the simulated surface pressure pattern. Based upon this, we present our current suggested improved model setup for seasonal experiments.
Y1 - 2021
U6 - https://doi.org/10.1029/2021EA001676
SN - 2333-5084
VL - 8
IS - 3
PB - American Geophysical Union
CY - Malden, Mass.
ER -
TY - JOUR
A1 - Pelisoli, Ingrid
A1 - Vos, Joris
A1 - Geier, Stephan
A1 - Schaffenroth, Veronika
A1 - Baran, Andrzej S.
T1 - Alone but not lonely
BT - observational evidence that binary interaction is always required to form hot subdwarf stars
JF - Astronomy and astrophysics : an international weekly journal
N2 - Context. Hot subdwarfs are core-helium burning stars that show lower masses and higher temperatures than canonical horizontal branch stars. They are believed to be formed when a red giant suffers an extreme mass-loss episode. Binary interaction is suggested to be the main formation channel, but the high fraction of apparently single hot subdwarfs (up to 30%) has prompted single star formation scenarios to be proposed.Aims. We investigate the possibility that hot subdwarfs could form without interaction by studying wide binary systems. If single formation scenarios were possible, there should be hot subdwarfs in wide binaries that have undergone no interaction.Methods. Angular momentum accretion during interaction is predicted to cause the hot subdwarf companion to spin up to the critical velocity. The effect of this should still be observable given the timescales of the hot subdwarf phase. To study the rotation rates of companions, we have analysed light curves from the Transiting Exoplanet Survey Satellite for all known hot subdwarfs showing composite spectral energy distributions indicating the presence of a main sequence wide binary companion. If formation without interaction were possible, that would also imply the existence of hot subdwarfs in very wide binaries that are not predicted to interact. To identify such systems, we have searched for common proper motion companions with projected orbital distances of up to 0.1 pc to all known spectroscopically confirmed hot subdwarfs using Gaia DR2 astrometry.Results. We find that the companions in composite hot subdwarfs show short rotation periods when compared to field main sequence stars. They display a triangular-shaped distribution with a peak around 2.5 days, similar to what is observed for young open clusters. We also report a shortage of hot subdwarfs with candidate common proper motion companions. We identify only 16 candidates after probing 2938 hot subdwarfs with good astrometry. Out of those, at least six seem to be hierarchical triple systems, in which the hot subdwarf is part of an inner binary.Conclusions. The observed distribution of rotation rates for the companions in known wide hot subdwarf binaries provides evidence of previous interaction causing spin-up. Additionally, there is a shortage of hot subdwarfs in common proper motion pairs, considering the frequency of such systems among progenitors. These results suggest that binary interaction is always required for the formation of hot subdwarfs.
KW - subdwarfs
KW - binaries: general
KW - stars: variables: general
Y1 - 2020
U6 - https://doi.org/10.1051/0004-6361/202038473
SN - 0004-6361
SN - 1432-0746
VL - 642
PB - EDP Sciences
CY - Les Ulis
ER -
TY - GEN
A1 - Maier, Philipp
A1 - Wolf, Jürgen
A1 - Keilig, Thomas
A1 - Krabbe, Alfred
A1 - Duffard, Rene
A1 - Ortiz, Jose-Luis
A1 - Klinkner, Sabine
A1 - Lengowski, Michael
A1 - Müller, Thomas
A1 - Lockowandt, Christian
A1 - Krockstedt, Christian
A1 - Kappelmann, Norbert
A1 - Stelzer, Beate
A1 - Werner, Klaus
A1 - Geier, Stephan
A1 - Kalkuhl, Christoph
A1 - Rauch, Thomas
A1 - Schanz, Thomas
A1 - Barnstedt, Jürgen
A1 - Conti, Lauro
A1 - Hanke, Lars
T1 - Towards a European Stratospheric Balloon Observatory
BT - the ESBO design study
T2 - Ground-based and Airborne Telescopes VII
N2 - This paper presents the concept of a community-accessible stratospheric balloon-based observatory that is currently under preparation by a consortium of European research institutes and industry. We present the technical motivation, science case, instrumentation, and a two-stage image stabilization approach of the 0.5-m UV/visible platform. In addition, we briefly describe the novel mid-sized stabilized balloon gondola under design to carry telescopes in the 0.5 to 0.6 m range as well as the currently considered flight option for this platform. Secondly, we outline the scientific and technical motivation for a large balloon-based FIR telescope and the ESBO DS approach towards such an infrastructure.
KW - astronomy
KW - balloon telescopes
KW - UV
KW - far infrared
KW - detectors
KW - observatory
Y1 - 2018
SN - 978-1-5106-1954-8
U6 - https://doi.org/10.1117/12.2319248
SN - 0277-786X
SN - 1996-756X
VL - 10700
PB - SPIE-INT Soc Optical Engineering
CY - Bellingham
ER -
TY - JOUR
A1 - Irrgang, Andreas
A1 - Geier, Stephan
A1 - Heber, Ulrich
A1 - Kupfer, Thomas
A1 - Fürst, F.
T1 - PG 1610+062: a runaway B star challenging classical ejection mechanisms
JF - Astronomy and astrophysics : an international weekly journal
N2 - Hypervelocity stars are rare objects, mostly main-sequence (MS) B stars, traveling so fast that they will eventually escape from the Milky Way. Recently, it has been shown that the popular Hills mechanism, in which a binary system is disrupted via a close encounter with the supermassive black hole at the Galactic center, may not be their only ejection mechanism. The analyses of Gaia data ruled out a Galactic center origin for some of them, and instead indicated that they are extreme disk runaway stars ejected at velocities exceeding the predicted limits of classical scenarios (dynamical ejection from star clusters or binary supernova ejection). We present the discovery of a new extreme disk runaway star, PG 1610+062, which is a slowly pulsating B star bright enough to be studied in detail. A quantitative analysis of spectra taken with ESI at the Keck Observatory revealed that PG 1610+062 is a late B-type MS star of 4–5 M⊙ with low projected rotational velocity. Abundances (C, N, O, Ne, Mg, Al, Si, S, Ar, and Fe) were derived differentially with respect to the normal B star HD 137366 and indicate that PG 1610+062 is somewhat metal rich. A kinematic analysis, based on our spectrophotometric distance (17.3 kpc) and on proper motions from Gaia’s second data release, shows that PG 1610+062 was probably ejected from the Carina-Sagittarius spiral arm at a velocity of 550 ± 40 km s−1, which is beyond the classical limits. Accordingly, the star is in the top five of the most extreme MS disk runaway stars and is only the second among the five for which the chemical composition is known.
KW - stars: abundances
KW - stars: individual: HD 137366
KW - stars: kinematics and dynamics
KW - stars: individual: PG 1610+062
KW - stars: early-type
Y1 - 2019
U6 - https://doi.org/10.1051/0004-6361/201935429
SN - 1432-0746
VL - 628
PB - EDP Sciences
CY - Les Ulis
ER -
TY - JOUR
A1 - Ratzloff, Jeffrey K.
A1 - Barlow, Brad N.
A1 - Kupfer, Thomas
A1 - Corcoran, Kyle A.
A1 - Geier, Stephan
A1 - Bauer, Evan
A1 - Corbett, Henry T.
A1 - Howard, Ward S.
A1 - Glazier, Amy
A1 - Law, Nicholas M.
T1 - EVR-CB-001: An Evolving, Progenitor, White Dwarf Compact Binary Discovered with the Evryscope
JF - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2 - We present EVR-CB-001, the discovery of a compact binary with an extremely low-mass (0.21 +/- 0.05M(circle dot)) helium core white dwarf progenitor (pre-He WD) and an unseen low-mass (0.32 +/- 0.06M(circle dot)) helium white dwarf (He WD) companion. He WDs are thought to evolve from the remnant helium-rich core of a main-sequence star stripped during the giant phase by a close companion. Low-mass He WDs are exotic objects (only about 0.2% of WDs are thought to be less than 0.3 M-circle dot), and are expected to be found in compact binaries. Pre-He WDs are even rarer, and occupy the intermediate phase after the core is stripped, but before the star becomes a fully degenerate WD and with a larger radius (approximate to 0.2R(circle dot)) than a typical WD. The primary component of EVR-CB-001 (the pre-He WD) was originally thought to be a hot subdwarf (sdB) star from its blue color and under-luminous magnitude, characteristic of sdBs. The mass, temperature (T-eff = 18,500 +/- 500 K), and surface gravity (log(g) = 4.96 +/- 0.04) solutions from this work are lower than values for typical hot subdwarfs. The primary is likely to be a post-red-giant branch, pre-He WD contracting into a He WD, and at a stage that places it nearest to sdBs on color-magnitude and T-eff-log(g) diagrams. EVR-CB-001 is expected to evolve into a fully double degenerate, compact system that should spin down and potentially evolve into a single hot subdwarf star. Single hot subdwarfs are observed, but progenitor systems have been elusive.
Y1 - 2019
U6 - https://doi.org/10.3847/1538-4357/ab3727
SN - 0004-637X
SN - 1538-4357
VL - 883
IS - 1
PB - IOP Publ. Ltd.
CY - Bristol
ER -
TY - JOUR
A1 - Romanowsky, Erik
A1 - Handorf, Dörthe
A1 - Jaiser, Ralf
A1 - Wohltmann, Ingo
A1 - Dorn, Wolfgang
A1 - Ukita, Jinro
A1 - Cohen, Judah
A1 - Dethloff, Klaus
A1 - Rex, Markus
T1 - The role of stratospheric ozone for Arctic-midlatitude linkages
JF - Scientific reports
N2 - Arctic warming was more pronounced than warming in midlatitudes in the last decades making this region a hotspot of climate change. Associated with this, a rapid decline of sea-ice extent and a decrease of its thickness has been observed. Sea-ice retreat allows for an increased transport of heat and momentum from the ocean up to the tropo- and stratosphere by enhanced upward propagation of planetary-scale atmospheric waves. In the upper atmosphere, these waves deposit the momentum transported, disturbing the stratospheric polar vortex, which can lead to a breakdown of this circulation with the potential to also significantly impact the troposphere in mid- to late-winter and early spring. Therefore, an accurate representation of stratospheric processes in climate models is necessary to improve the understanding of the impact of retreating sea ice on the atmospheric circulation. By modeling the atmospheric response to a prescribed decline in Arctic sea ice, we show that including interactive stratospheric ozone chemistry in atmospheric model calculations leads to an improvement in tropo-stratospheric interactions compared to simulations without interactive chemistry. This suggests that stratospheric ozone chemistry is important for the understanding of sea ice related impacts on atmospheric dynamics.
Y1 - 2019
U6 - https://doi.org/10.1038/s41598-019-43823-1
SN - 2045-2322
VL - 9
PB - Nature Publ. Group
CY - London
ER -
TY - JOUR
A1 - Geier, Stephan
A1 - Raddi, Roberto
A1 - Fusillo, Nicola Pietro Gentile
A1 - Marsh, T. R.
T1 - The population of hot subdwarf stars studied with Gaia
BT - II. The Gaia DR2 catalogue of hot subluminous stars
JF - Astronomy and astrophysics : an international weekly journal
N2 - Based on data from the ESA Gaia Data Release 2 (DR2) and several ground-based, multi-band photometry surveys we have compiled an all-sky catalogue of 39 800 hot subluminous star candidates selected in Gaia DR2 by means of colour, absolute magnitude, and reduced proper motion cuts. We expect the majority of the candidates to be hot subdwarf stars of spectral type B and O, followed by blue horizontal branch stars of late B-type (HBB), hot post-AGB stars, and central stars of planetary nebulae. The contamination by cooler stars should be about 10%. The catalogue is magnitude limited to Gaia G < 19 mag and covers the whole sky. Except within the Galactic plane and LMC/SMC regions, we expect the catalogue to be almost complete up to about 1.5 kpc. The main purpose of this catalogue is to serve as input target list for the large-scale photometric and spectroscopic surveys which are ongoing or scheduled to start in the coming years. In the long run, securing a statistically significant sample of spectroscopically confirmed hot subluminous stars is key to advance towards a more detailed understanding of the latest stages of stellar evolution for single and binary stars.
KW - subdwarfs
KW - stars: horizontal-branch
KW - catalogs
Y1 - 2019
U6 - https://doi.org/10.1051/0004-6361/201834236
SN - 0004-6361
SN - 1432-0746
VL - 621
PB - EDP Sciences
CY - Les Ulis
ER -
TY - GEN
A1 - Finch, Nicolle L.
A1 - Braker, I. P.
A1 - Reindl, Nicole
A1 - Barstow, Martin A.
A1 - Casewell, Sarah L.
A1 - Burleigh, M.
A1 - Kupfer, Thomas
A1 - Kilkenny, D.
A1 - Geier, Stephan
A1 - Schaffenroth, Veronika
A1 - Bertolami Miller, Marcelo Miguel
A1 - Taubenberger, Stefan
A1 - Freudenthal, Joseph
T1 - Spectral Analysis of Binary Pre-white Dwarf Systems
T2 - Radiative signatures from the cosmos
N2 - Short period double degenerate white dwarf (WD) binaries with periods of less than similar to 1 day are considered to be one of the likely progenitors of type Ia supernovae. These binaries have undergone a period of common envelope evolution. If the core ignites helium before the envelope is ejected, then a hot subdwarf remains prior to contracting into a WD. Here we present a comparison of two very rare systems that contain two hot subdwarfs in short period orbits. We provide a quantitative spectroscopic analysis of the systems using synthetic spectra from state-of-the-art non-LTE models to constrain the atmospheric parameters of the stars. We also use these models to determine the radial velocities, and thus calculate dynamical masses for the stars in each system.
Y1 - 2019
SN - 978-1-58381-925-8
SN - 1050-3390
VL - 519
SP - 231
EP - 238
PB - Astronomical soc pacific
CY - San Fransisco
ER -
TY - JOUR
A1 - Bouakline, Foudhil
A1 - Saalfrank, Peter
T1 - Seemingly asymmetric atom-localized electronic densities following laser-dissociation of homonuclear diatomics
JF - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistry
N2 - Recent experiments on laser-dissociation of aligned homonuclear diatomic molecules show an asymmetric forward-backward (spatial) electron-localization along the laser polarization axis. Most theoretical models attribute this asymmetry to interference effects between gerade and ungerade vibronic states. Presumably due to alignment, these models neglect molecular rotations and hence infer an asymmetric (post-dissociation) charge distribution over the two identical nuclei. In this paper, we question the equivalence that is made between spatial electron-localization, observed in experiments, and atomic electron-localization, alluded by these theoretical models. We show that (seeming) agreement between these models and experiments is due to an unfortunate omission of nuclear permutation symmetry, i.e., quantum statistics. Enforcement of the latter requires mandatory inclusion of the molecular rotational degree of freedom, even for perfectly aligned molecules. Unlike previous interpretations, we ascribe spatial electron-localization to the laser creation of a rovibronic wavepacket that involves field-free molecular eigenstates with opposite space-inversion symmetry i.e., even and odd parity. Space-inversion symmetry breaking would then lead to an asymmetric distribution of the (space-fixed) electronic density over the forward and backward hemisphere. However, owing to the simultaneous coexistence of two indistinguishable molecular orientational isomers, our analytical and computational results show that the post-dissociation electronic density along a specified space-fixed axis is equally shared between the two identical nuclei-a result that is in perfect accordance with the principle of the indistinguishability of identical particles. Published under an exclusive license by AIP Publishing.
Y1 - 2021
U6 - https://doi.org/10.1063/5.0049710
SN - 0021-9606
SN - 1089-7690
VL - 154
IS - 23
PB - American Institute of Physics
CY - Melville
ER -
TY - JOUR
A1 - Omel'chenko, Oleh
A1 - Ocampo-Espindola, Jorge Luis
A1 - Kiss, István Z.
T1 - Asymmetry-induced isolated fully synchronized state in coupled oscillator populations
JF - Physical review : E, Statistical, nonlinear and soft matter physics
N2 - A symmetry-breaking mechanism is investigated that creates bistability between fully and partially synchronized states in oscillator networks. Two populations of oscillators with unimodal frequency distribution and different amplitudes, in the presence of weak global coupling, are shown to simplify to a modular network with asymmetrical coupling. With increasing the coupling strength, a synchronization transition is observed with an isolated fully synchronized state. The results are interpreted theoretically in the thermodynamic limit and confirmed in experiments with chemical oscillators.
Y1 - 2021
U6 - https://doi.org/10.1103/PhysRevE.104.L022202
SN - 2470-0045
SN - 2470-0053
VL - 104
IS - 2
PB - American Physical Society
CY - Melville, NY
ER -
TY - JOUR
A1 - Meyer, Dominique M.-A.
A1 - Pohl, Martin
A1 - Petrov, Miroslav
A1 - Egberts, Kathrin
T1 - Mixing of materials in magnetized core-collapse supernova remnants
JF - Monthly notices of the Royal Astronomical Society
N2 - Core-collapse supernova remnants are structures of the interstellar medium (ISM) left behind the explosive death of most massive stars ( ?40 M-?). Since they result in the expansion of the supernova shock wave into the gaseous environment shaped by the star's wind history, their morphology constitutes an insight into the past evolution of their progenitor star. Particularly, fast-mo ving massiv e stars can produce asymmetric core-collapse superno va remnants. We inv estigate the mixing of materials in core-collapse supernova remnants generated by a moving massive 35 M-? star, in a magnetized ISM. Stellar rotation and the wind magnetic field are time-dependently included into the models which follow the entire evolution of the stellar surroundings from the zero-age main-sequence to 80 kyr after the supernova explosion. It is found that very little main-sequence material is present in remnants from moving stars, that the Wolf-Rayet wind mixes very efficiently within the 10 kyr after the explosion, while the red supergiant material is still unmixed by 30 per cent within 50 kyr after the supernova. Our results indicate that the faster the stellar motion, the more complex the internal organization of the supernova remnant and the more ef fecti ve the mixing of ejecta therein. In contrast, the mixing of stellar wind material is only weakly affected by progenitor motion, if at all.
KW - ISM : supernova remnants
KW - (magnetohydrodynamics) MHD
KW - stars evolution
KW - stars: massive
Y1 - 2023
U6 - https://doi.org/10.1093/mnras/stad906
SN - 0035-8711
SN - 1365-2966
VL - 521
IS - 4
SP - 5354
EP - 5371
PB - Oxford Univ. Press
CY - Oxford
ER -
TY - JOUR
A1 - Dahlenburg, Marcus
A1 - Chechkin, Aleksei
A1 - Schumer, Rina
A1 - Metzler, Ralf
T1 - Stochastic resetting by a random amplitude
JF - Physical review : E, Statistical, nonlinear and soft matter physics
N2 - Stochastic resetting, a diffusive process whose amplitude is reset to the origin at random times, is a vividly studied strategy to optimize encounter dynamics, e.g., in chemical reactions. Here we generalize the resetting step by introducing a random resetting amplitude such that the diffusing particle may be only partially reset towards the trajectory origin or even overshoot the origin in a resetting step. We introduce different scenarios for the random-amplitude stochastic resetting process and discuss the resulting dynamics. Direct applications are geophysical layering (stratigraphy) and population dynamics or financial markets, as well as generic search processes.
Y1 - 2021
U6 - https://doi.org/10.1103/PhysRevE.103.052123
SN - 2470-0045
SN - 2470-0053
VL - 103
IS - 5
PB - American Physical Society
CY - Woodbury, NY
ER -
TY - CHAP
A1 - Wang, Zhenyu
A1 - Breternitz, Joachim
A1 - Schorr, Susan
T1 - Cation disorder in zinc-group IV- nitride and oxide nitride semiconductor materials revealed through neutron diffraction
T2 - Acta crystallographica / International Union of Crystallography. Section A, Foundations and advances
KW - nitride materials
KW - semiconductors
KW - structure-property relationships
Y1 - 2021
SN - 2053-2733
VL - 77
IS - Suppl.
SP - C1077
EP - C1077
PB - Blackwell
CY - Oxford [u.a.]
ER -