@article{RyabchunKolloscheWegeneretal.2016, author = {Ryabchun, Alexander and Kollosche, Matthias and Wegener, Michael and Sakhno, Oksana}, title = {Holographic Structuring of Elastomer Actuator: First True Monolithic Tunable Elastomer Optics}, series = {Advanced materials}, volume = {28}, journal = {Advanced materials}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0935-9648}, doi = {10.1002/adma.201602881}, pages = {10217 -- 10223}, year = {2016}, abstract = {Volume diffraction gratings (VDGs) are inscribed selectively by diffusive introduction of benzophenone and subsequent UV-holographic structuring into an electroactive dielectric elastomer actuator (DEA), to afford a continuous voltage-controlled grating shift of 17\%. The internal stress coupling of DEA and optical domain allows for a new generation of true monolithic tunable elastomer optics with voltage controlled properties.}, language = {en} } @phdthesis{Ruppert2016, author = {Ruppert, Jan}, title = {The Low-Mass Young Stellar Content in the Extended Environment of the Galactic Starburst Region NGC3603}, school = {Universit{\"a}t Potsdam}, pages = {148}, year = {2016}, language = {en} } @article{RoshchupkinOrtegaPlotitcynaetal.2016, author = {Roshchupkin, Dmitry and Ortega, Luc and Plotitcyna, Olga and Erko, Alexei and Zizak, Ivo and Vadilonga, Simone and Irzhak, Dmitry and Emelin, Evgenii and Buzanov, Oleg and Leitenberger, Wolfram}, title = {Piezoelectric Ca3NbGa3Si2O14 crystal: crystal growth, piezoelectric and acoustic properties}, series = {Journal of geophysical research : Space physics}, volume = {122}, journal = {Journal of geophysical research : Space physics}, publisher = {Springer}, address = {New York}, issn = {0947-8396}, doi = {10.1007/s00339-016-0279-1}, pages = {2803 -- 2812}, year = {2016}, abstract = {Ca3NbGa3Si2O14 (CNGS), a five-component crystal of lanthanum-gallium silicate group, was grown by the Czochralski method. The parameters of the elementary unit cell of the crystal were measured by powder diffraction. The independent piezoelectric strain coefficients d(11) and d(14) were determined by the triple-axis X-ray diffraction in the Bragg and Laue geometries. Excitation and propagation of surface acoustic waves (SAW) were studied by high-resolution X-ray diffraction at BESSY II synchrotron radiation source. The velocity of SAW propagation and power flow angles in the Y-, X-and yxl/+36 degrees-cuts of the CNGS crystal were determined from the analysis of the diffraction spectra. The CNGS crystal was found practically isotropic by its acoustic properties.}, language = {en} } @article{RomitaLadaCioni2016, author = {Romita, Krista and Lada, Elizabeth and Cioni, Maria-Rosa L.}, title = {EMBEDDED CLUSTERS IN THE LARGE MAGELLANIC CLOUD USING THE VISTA MAGELLANIC CLOUDS SURVEY}, series = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, volume = {821}, journal = {The astrophysical journal : an international review of spectroscopy and astronomical physics}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {0004-637X}, doi = {10.3847/0004-637X/821/1/51}, pages = {10}, year = {2016}, abstract = {We present initial results of the first large-scale survey of embedded star clusters in molecular clouds in the Large Magellanic Cloud (LMC) using near-infrared imaging from the Visible and Infrared Survey Telescope for Astronomy Magellanic Clouds Survey. We explored a ~1.65 deg2 area of the LMC, which contains the well-known star-forming region 30 Doradus as well as ~14\% of the galaxy's CO clouds, and identified 67 embedded cluster candidates, 45 of which are newly discovered as clusters. We have determined the sizes, luminosities, and masses for these embedded clusters, examined the star formation rates (SFRs) of their corresponding molecular clouds, and made a comparison between the LMC and the Milky Way. Our preliminary results indicate that embedded clusters in the LMC are generally larger, more luminous, and more massive than those in the local Milky Way. We also find that the surface densities of both embedded clusters and molecular clouds is ~3 times higher than in our local environment, the embedded cluster mass surface density is ~40 times higher, the SFR is ~20 times higher, and the star formation efficiency is ~10 times higher. Despite these differences, the SFRs of the LMC molecular clouds are consistent with the SFR scaling law presented in Lada et al. This consistency indicates that while the conditions of embedded cluster formation may vary between environments, the overall process within molecular clouds may be universal.}, language = {en} } @article{RipollLoridanCunninghametal.2016, author = {Ripoll, Jean-Fran{\c{c}}ois and Loridan, Vivien and Cunningham, G. S. and Reeves, Geoffrey D. and Shprits, Yuri Y.}, title = {On the time needed to reach an equilibrium structure of the radiation belts}, series = {Journal of geophysical research : Space physics}, volume = {121}, journal = {Journal of geophysical research : Space physics}, publisher = {American Geophysical Union}, address = {Washington}, issn = {2169-9380}, doi = {10.1002/2015JA022207}, pages = {7684 -- 7698}, year = {2016}, abstract = {In this study, we complement the notion of equilibrium states of the radiation belts with a discussion on the dynamics and time needed to reach equilibrium. We solve for the equilibrium states obtained using 1-D radial diffusion with recently developed hiss and chorus lifetimes at constant values of Kp = 1, 3, and 6. We find that the equilibrium states at moderately low Kp, when plotted versus L shell (L) and energy (E), display the same interesting S shape for the inner edge of the outer belt as recently observed by the Van Allen Probes. The S shape is also produced as the radiation belts dynamically evolve toward the equilibrium state when initialized to simulate the buildup after a massive dropout or to simulate loss due to outward diffusion from a saturated state. Physically, this shape, intimately linked with the slot structure, is due to the dependence of electron loss rate (originating from wave-particle interactions) on both energy and L shell. Equilibrium electron flux profiles are governed by the Biot number (tau(Diffusion)/tau(loss)), with large Biot number corresponding to low fluxes and low Biot number to large fluxes. The time it takes for the flux at a specific (L, E) to reach the value associated with the equilibrium state, starting from these different initial states, is governed by the initial state of the belts, the property of the dynamics (diffusion coefficients), and the size of the domain of computation. Its structure shows a rather complex scissor form in the (L, E) plane. The equilibrium value (phase space density or flux) is practically reachable only for selected regions in (L, E) and geomagnetic activity. Convergence to equilibrium requires hundreds of days in the inner belt for E>300 keV and moderate Kp (<= 3). It takes less time to reach equilibrium during disturbed geomagnetic conditions (Kp = 3), when the system evolves faster. Restricting our interest to the slot region, below L = 4, we find that only small regions in (L, E) space can reach the equilibrium value: E similar to [200, 300] keV for L= [3.7, 4] at Kp= 1, E similar to[0.6, 1] MeV for L = [3, 4] at Kp = 3, and E similar to 300 keV for L = [3.5, 4] at Kp = 6 assuming no new incoming electrons.}, language = {en} } @article{RipepiMarconiMorettietal.2016, author = {Ripepi, Vincenzo and Marconi, M. and Moretti, M. I. and Clementini, Gisella and Cioni, Maria-Rosa L. and de Grijs, Richard and Emerson, J. P. and Groenewegen, M. A. T. and Ivanov, V. D. and Piatti, A. E.}, title = {THE VMC SURVEY. XIX. CLASSICAL CEPHEIDS IN THE SMALL MAGELLANIC CLOUD}, series = {The astrophysical journal : an international review of spectroscopy and astronomical physics ; Supplement series}, volume = {224}, journal = {The astrophysical journal : an international review of spectroscopy and astronomical physics ; Supplement series}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {0067-0049}, doi = {10.3847/0067-0049/224/2/21}, pages = {199 -- 229}, year = {2016}, abstract = {The "VISTA near-infrared YJK(s) survey of the Magellanic Clouds System" (VMC) is collecting deep K-s-band time-series photometry of pulsating variable stars hosted by the two Magellanic Clouds and their connecting Bridge. In this paper, we present Y, J, K-s light curves for a sample of 4172 Small Magellanic Cloud (SMC) Classical Cepheids (CCs). These data, complemented with literature V values, allowed us to construct a variety of period-luminosity (PL), period-luminosity-color (PLC), and period-Wesenheit (PW) relationships, which are valid for Fundamental (F), First Overtone (FO), and Second Overtone (SO) pulsators. The relations involving the V, J, K-s bands are in agreement with their counterparts in the literature. As for the Y band, to our knowledge, we present the first CC PL, PW, and PLC relations ever derived using this filter. We also present the first near-infrared PL, PW, and PLC relations for SO pulsators to date. We used PW(V, K-s) to estimate the relative SMC-LMC distance and, in turn, the absolute distance to the SMC. For the former quantity, we find a value of Delta mu = 0.55. +/- 0.04 mag, which is in rather good agreement with other evaluations based on CCs, but significantly larger than the results obtained from older population II distance indicators. This discrepancy might be due to the different geometric distributions of young and old tracers in both Clouds. As for the absolute distance to the SMC, our best estimates are mu(SMC) = 19.01 +/- 0.05 mag and mu(SMC) = 19.04 +/- 0.06 mag, based on two distance measurements to the LMC which rely on accurate CC and eclipsing Cepheid binary data, respectively.}, language = {en} } @article{RichterWakkerFechneretal.2016, author = {Richter, Philipp and Wakker, Bart P. and Fechner, Cora and Herenz, Peter and Tepper-Garcia, T. and Fox, Andrew J.}, title = {An HST/COS legacy survey of intervening Si III absorption in the extended gaseous halos of low-redshift galaxies}, series = {Climate : open access journal}, volume = {590}, journal = {Climate : open access journal}, publisher = {EDP Sciences}, address = {Les Ulis}, issn = {1432-0746}, doi = {10.1051/0004-6361/201527038}, pages = {29}, year = {2016}, abstract = {Aims. Doubly ionized silicon (Si III) is a powerful tracer of diffuse ionized gas inside and outside of galaxies. It can be observed in the local Universe in ultraviolet (UV) absorption against bright extragalactic background sources. We here present an extensive study of intervening Si III-selected absorbers and study the properties of the warm circumgalactic medium (CGM) around low-redshift (z <= 0.1) galaxies. Methods. We analyzed the UV absorption spectra of 303 extragalactic background sources, as obtained with the Cosmic Origins Spectrograph (COS) on-board the Hubble Space Telescope (HST). We developed a geometrical model for the absorption-cross section of the CGM around the local galaxy population and compared the observed Si III absorption statistics with predictions provided by the model. We also compared redshifts and positions of the absorbers with those of similar to 64 000 galaxies using archival galaxy-survey data to investigate the relation between intervening Si III absorbers and the CGM. Results. Along a total redshift path of Delta z approximate to 24, we identify 69 intervening Si III systems that all show associated absorption from other low and high ions (e.g., H I, Si II, Si IV, C II, C IV). We derive a bias-corrected number density of dN/dz(Si III) = 2.5 +/- 0.4 for absorbers with column densities log N(Si III) > 12.2, which is similar to 3 times the number density of strong Mg II systems at z = 0. This number density matches the expected cross section of a Si III absorbing CGM around the local galaxy population with a mean covering fraction of < f(c)> = 0.69. For the majority (similar to 60 percent) of the absorbers, we identify possible host galaxies within 300 km s(-1) of the absorbers and derive impact parameters rho < 200 kpc, demonstrating that the spatial distributions of Si III absorbers and galaxies are highly correlated. Conclusions. Our study indicates that the majority of Si III-selected absorbers in our sample trace the CGM of nearby galaxies within their virial radii at a typical covering fraction of similar to 70 percent. We estimate that diffuse gas in the CGM around galaxies, as traced by Si III, contains substantially more (more than twice as much) baryonic mass than their neutral interstellar medium.}, language = {en} } @article{RichardsonShenarRoyLoubieretal.2016, author = {Richardson, Noel D. and Shenar, Tomer and Roy-Loubier, Olivier and Schaefer, Gail and Moffat, Anthony F. J. and St-Louis, Nicole and Gies, Douglas R. and Farrington, Chris and Hill, Grant M. and Williams, Peredur M. and Gordon, Kathryn and Pablo, Herbert and Ramiaramanantsoa, Tahina}, title = {The CHARA Array resolves the long-period Wolf-Rayet binaries WR 137 and WR 138}, series = {Monthly notices of the Royal Astronomical Society}, volume = {461}, journal = {Monthly notices of the Royal Astronomical Society}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0035-8711}, doi = {10.1093/mnras/stw1585}, pages = {4115 -- 4124}, year = {2016}, abstract = {We report on interferometric observations with the CHARAArray of two classical Wolf-Rayet (WR) stars in suspected binary systems, namely WR 137 and WR 138. In both cases, we resolve the component stars to be separated by a few milliarcseconds. The data were collected in the H band, and provide a measure of the fractional flux for both stars in each system. We find that the WR star is the dominant H-band light source in both systems (fWR, 137 = 0.59 +/- 0.04; fWR, 138 = 0.67 +/- 0.01), which is confirmed through both comparisons with estimated fundamental parameters for WR stars and O dwarfs, as well as through spectral modelling of each system. Our spectral modelling also provides fundamental parameters for the stars and winds in these systems. The results on WR 138 provide evidence that it is a binary system which may have gone through a previous mass-transfer episode to create the WR star. The separation and position of the stars in the WR 137 system together with previous results from the IOTA interferometer provides evidence that the binary is seen nearly edgeon. The possible edge-on orbit of WR 137 aligns well with the dust production site imaged by the Hubble Space Telescope during a previous periastron passage, showing that the dust production may be concentrated in the orbital plane.}, language = {en} } @phdthesis{Rezanezhad2016, author = {Rezanezhad, Vahid}, title = {Inversion of the 2004 M6.0 Parkfield Earthquake Coseismic Offsets by Partition Model}, school = {Universit{\"a}t Potsdam}, pages = {83}, year = {2016}, language = {en} } @phdthesis{Rettig2016, author = {Rettig, Robert}, title = {{\"U}ber die Anisotropie der Kosmischen Strahlung}, school = {Universit{\"a}t Potsdam}, pages = {90, XV}, year = {2016}, language = {de} }