@article{GoettgensWeilbacherRothetal.2019, author = {G{\"o}ttgens, Fabian and Weilbacher, Peter Michael and Roth, Martin M. and Dreizler, Stefan and Giesers, Benjamin and Husser, Tim-Oliver and Kamann, Sebastian and Brinchmann, Jarle and Kollatschny, Wolfram and Monreal-Ibero, Ana and Schmidt, Kasper Borello and Wendt, Martin and Wisotzki, Lutz and Bacon, Roland}, title = {Discovery of an old nova remnant in the Galactic globular cluster M 22}, series = {Astronomy and astrophysics : an international weekly journal}, volume = {626}, journal = {Astronomy and astrophysics : an international weekly journal}, publisher = {EDP Sciences}, address = {Les Ulis}, issn = {1432-0746}, doi = {10.1051/0004-6361/201935221}, pages = {6}, year = {2019}, abstract = {A nova is a cataclysmic event on the surface of a white dwarf in a binary system that increases the overall brightness by several orders of magnitude. Although binary systems with a white dwarf are expected to be overabundant in globular clusters compared with in the Galaxy, only two novae from Galactic globular clusters have been observed. We present the discovery of an emission nebula in the Galactic globular cluster M 22 (NGC 6656) in observations made with the integral-field spectrograph MUSE. We extracted the spectrum of the nebula and used the radial velocity determined from the emission lines to confirm that the nebula is part of NGC 6656. Emission-line ratios were used to determine the electron temperature and density. It is estimated to have a mass of 1-17 x 10(-5) M-circle dot. This mass and the emission-line ratios indicate that the nebula is a nova remnant. Its position coincides with the reported location of a "guest star", an ancient Chinese term for transients, observed in May 48 BCE. With this discovery, this nova may be one of the oldest confirmed extra-solar events recorded in human history.}, language = {en} } @misc{MegowRoehrSchmidtamBuschetal.2015, author = {Megow, J{\"o}rg and R{\"o}hr, Merle I. S. and Schmidt am Busch, Marcel and Renger, Thomas and Mitrić, Roland and Kirstein, Stefan and Rabe, J{\"u}rgen P. and May, Volkhard}, title = {Site-dependence of van der Waals interaction explains exciton spectra of double-walled tubular J-aggregates}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-79978}, pages = {6741 -- 6747}, year = {2015}, abstract = {The simulation of the optical properties of supramolecular aggregates requires the development of methods, which are able to treat a large number of coupled chromophores interacting with the environment. Since it is currently not possible to treat large systems by quantum chemistry, the Frenkel exciton model is a valuable alternative. In this work we show how the Frenkel exciton model can be extended in order to explain the excitonic spectra of a specific double-walled tubular dye aggregate explicitly taking into account dispersive energy shifts of ground and excited states due to van der Waals interaction with all surrounding molecules. The experimentally observed splitting is well explained by the site-dependent energy shift of molecules placed at the inner or outer side of the double-walled tube, respectively. Therefore we can conclude that inclusion of the site-dependent dispersive effect in the theoretical description of optical properties of nanoscaled dye aggregates is mandatory.}, language = {en} } @article{MegowRoehrSchmidtamBuschetal.2015, author = {Megow, J{\"o}rg and R{\"o}hr, Merle I. S. and Schmidt am Busch, Marcel and Renger, Thomas and Mitrić, Roland and Kirstein, Stefan and Rabe, J{\"u}rgen P. and May, Volkhard}, title = {Site-dependence of van der Waals interaction explains exciton spectra of double-walled tubular J-aggregates}, series = {Physical chemistry, chemical physics : PCCP ; a journal of European chemical societies}, volume = {17}, journal = {Physical chemistry, chemical physics : PCCP ; a journal of European chemical societies}, number = {10}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1463-9084}, doi = {10.1039/c4cp05945j}, pages = {6741 -- 6747}, year = {2015}, abstract = {The simulation of the optical properties of supramolecular aggregates requires the development of methods, which are able to treat a large number of coupled chromophores interacting with the environment. Since it is currently not possible to treat large systems by quantum chemistry, the Frenkel exciton model is a valuable alternative. In this work we show how the Frenkel exciton model can be extended in order to explain the excitonic spectra of a specific double-walled tubular dye aggregate explicitly taking into account dispersive energy shifts of ground and excited states due to van der Waals interaction with all surrounding molecules. The experimentally observed splitting is well explained by the site-dependent energy shift of molecules placed at the inner or outer side of the double-walled tube, respectively. Therefore we can conclude that inclusion of the site-dependent dispersive effect in the theoretical description of optical properties of nanoscaled dye aggregates is mandatory.}, language = {en} } @article{KempfSramaGruenetal.2012, author = {Kempf, Sascha and Srama, Ralf and Gr{\"u}n, Eberhard and Mocker, Anna and Postberg, Frank and Hillier, Jon K. and Horanyi, Mihaly and Sternovsky, Zoltan and Abel, Bernd and Beinsen, Alexander and Thissen, Roland and Schmidt, J{\"u}rgen and Spahn, Frank and Altobelli, Nicolas}, title = {Linear high resolution dust mass spectrometer for a mission to the Galilean satellites}, series = {Planetary and space science}, volume = {65}, journal = {Planetary and space science}, number = {1}, publisher = {Elsevier}, address = {Oxford}, issn = {0032-0633}, doi = {10.1016/j.pss.2011.12.019}, pages = {10 -- 20}, year = {2012}, abstract = {The discovery of volcanic activity on Enceladus stands out amongst the long list of findings by the Cassini mission to Saturn. In particular the compositional analysis of Enceladus ice particles by Cassini's Cosmic Dust Analyser (CDA) (Srama et al., 2004) has proven to be a powerful technique for obtaining information about processes below the moon's ice crust. Small amounts of sodium salts embedded in the particles' ice matrices provide direct evidence for a subsurface liquid water reservoir, which is, or has been, in contact with the moon's rocky core (Postberg et al., 2009, 2011b). Jupiter's Galilean satellites Ganymede, Europa, and Callisto are also believed to have subsurface oceans and are therefore prime targets for future NASA and ESA outer Solar System missions. The Galilean moons are engulfed in tenuous dust clouds consisting of tiny pieces of the moons' surfaces (Kruger et al., 1999), released by hypervelocity impacts of micrometeoroids, which steadily bombard the surfaces of the moons. In situ chemical analysis of these grains by a high resolution dust spectrometer will provide spatially resolved mapping of the surface composition of Europa. Ganymede, and Callisto, meeting key scientific objectives of the planned missions. However, novel high-resolution reflectron-type dust mass spectrometers (Sternovsky et al., 2007; Srama et al., 2007) developed for dust astronomy missions (Gran et al., 2009) are probably not robust enough to be operated in the energetic radiation environment of the inner Jovian system. In contrast, CDA's linear spectrometer is much less affected by harsh radiation conditions because its ion detector is not directly facing out into space. The instrument has been continuously operated on Cassini for 11 years. In this paper we investigate the possibility of operating a CDA-like instrument as a high resolution impact mass spectrometer. We show that such an instrument is capable of reliably identifying traces of organic and inorganic materials in the ice matrix of ejecta expected to be generated from the surfaces of the Galilean moons. These measurements are complementary, and in some cases superior, compared to other traditional techniques such as infrared remote sensing or in situ ion or neutral mass spectrometers.}, language = {en} } @article{SchmidtPourteauCandanetal.2015, author = {Schmidt, Alexander and Pourteau, Amaury and Candan, Osman and Oberh{\"a}nsli, Roland}, title = {Lu-Hf geochronology on cm-sized garnets using microsampling: New constraints on garnet growth rates and duration of metamorphism during continental collision (Menderes Massif, Turkey)}, series = {Earth \& planetary science letters}, volume = {432}, journal = {Earth \& planetary science letters}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0012-821X}, doi = {10.1016/j.epsl.2015.09.015}, pages = {24 -- 35}, year = {2015}, abstract = {This study shows Lu-Hf geochronology of zoned garnet crystals contained in mica schists from the southern Menderes Massif, Turkey. Selected samples are four 3-5 cm large garnet megacrysts of which several consecutive garnet shells have been sampled with a micro-saw and analyzed for dating. The results are used to extract growth rates of garnet, and also to improve the time constraint for Alpine-aged overprint of the Pan-African basement in the Menderes Massif. The new data provides a precise age determination for prograde Barrovian metamorphism in the southern Menderes Massif, which so far was placed between 63 and 27 Ma on the basis of mica Rb-Sr and Ar-Ar dating. This study provides new constraints crucial to the understanding of the tectonic evolution of southwest Anatolia and the Aegean realm, as it yields a shorter outline for Alpine aged continental collision.}, language = {en} } @article{WeberAbuAyyashAbueladasetal.2004, author = {Weber, Michael H. and Abu-Ayyash, Khalil and Abueladas, Abdel-Rahman and Agnon, Amotz and Al-Amoush, H. and Babeyko, Andrey and Bartov, Yosef and Baumann, M. and Ben-Avraham, Zvi and Bock, G{\"u}nter and Bribach, Jens and El-Kelani, R. and Forster, A. and F{\"o}rster, Hans-J{\"u}rgen and Frieslander, U. and Garfunkel, Zvi and Grunewald, Steffen and Gotze, Hans-J{\"u}rgen and Haak, Volker and Haberland, Christian and Hassouneh, Mohammed and Helwig, S. and Hofstetter, Alfons and Jackel, K. H. and Kesten, Dagmar and Kind, Rainer and Maercklin, Nils and Mechie, James and Mohsen, Amjad and Neubauer, F. M. and Oberh{\"a}nsli, Roland and Qabbani, I. and Ritter, O. and Rumpker, G. and Rybakov, M. and Ryberg, Trond and Scherbaum, Frank and Schmidt, J. and Schulze, A. and Sobolev, Stephan Vladimir and Stiller, M. and Th,}, title = {The crustal structure of the Dead Sea Transform}, year = {2004}, abstract = {To address one of the central questions of plate tectonics-How do large transform systems work and what are their typical features?-seismic investigations across the Dead Sea Transform (DST), the boundary between the African and Arabian plates in the Middle East, were conducted for the first time. A major component of these investigations was a combined reflection/ refraction survey across the territories of Palestine, Israel and Jordan. The main results of this study are: (1) The seismic basement is offset by 3-5 km under the DST, (2) The DST cuts through the entire crust, broadening in the lower crust, (3) Strong lower crustal reflectors are imaged only on one side of the DST, (4) The seismic velocity sections show a steady increase in the depth of the crust-mantle transition (Moho) from 26 km at the Mediterranean to 39 km under the Jordan highlands, with only a small but visible, asymmetric topography of the Moho under the DST. These observations can be linked to the left-lateral movement of 105 km of the two plates in the last 17 Myr, accompanied by strong deformation within a narrow zone cutting through the entire crust. Comparing the DST and the San Andreas Fault (SAF) system, a strong asymmetry in subhorizontal lower crustal reflectors and a deep reaching deformation zone both occur around the DST and the SAF. The fact that such lower crustal reflectors and deep deformation zones are observed in such different transform systems suggests that these structures are possibly fundamental features of large transform plate boundaries}, language = {en} } @article{SchmidtHagenBreteetal.2010, author = {Schmidt, Roland and Hagen, Sebastian and Brete, Daniel and Carley, Robert and Gahl, Cornelius and Dokic, Jadranka and Saalfrank, Peter and Hecht, Stefan and Tegeder, Petra and Weinelt, Martin}, title = {On the electronic and geometrical structure of the trans- and cis-isomer of tetra-tert-butyl-azobenzene on Au(111)}, issn = {1463-9076}, doi = {10.1039/B924409c}, year = {2010}, abstract = {Near edge X-ray absorption. ne structure and X-ray photoelectron spectroscopy have been employed to follow the reversible trans to cis isomerization of tetra-tert-butyl-azobenzene (TBA) adsorbed on Au(111). For one monolayer the molecules adopt an adsorption geometry characteristic of the trans-TBA isomer. The azo-bridge (N = N) is aligned nearly parallel to the surface and the phenyl rings exhibit a planar orientation with a small tilt angle <= 4 degrees with respect to the surface normal. Illumination of the molecular layer at 455 nm triggers the trans to cis isomerization which is associated with a pronounced change of the geometrical and electronic structure. The N1s to pi* transition of the central azo-bridge shifts by 0.45 +/- 0.05 eV to higher photon energy and the transition dipole moment (TDM) is tilted by 59 +/- 5 degrees with respect to the surface normal. The pi-system of one phenyl ring is tilted by about 30 degrees with respect to the surface normal, while the second ring plane is oriented nearly perpendicular to the surface. This reorientation is supported by a shift and broadening of the C-H resonances associated with the tert-butyl legs of the molecule. These findings support a configuration of the photo-switched TBA molecule on Au(111) which is comparable to the cis-isomer of the free molecule. In the photo-stationary state 53 +/- 5\% of the TBA molecules are switched to the cis configuration. Thermal activation induces the back reaction to trans-TBA.}, language = {en} } @article{AyguelOkayOberhaenslietal.2015, author = {Ayg{\"u}l, Mesut and Okay, Aral I. and Oberh{\"a}nsli, Roland and Schmidt, Alexander and Sudo, Masafumi}, title = {Late Cretaceous infant intra-oceanic arc volcanism, the Central Pontides, Turkey: Petrogenetic and tectonic implications}, series = {Journal of Asian earth sciences}, volume = {111}, journal = {Journal of Asian earth sciences}, publisher = {Elsevier}, address = {Oxford}, issn = {1367-9120}, doi = {10.1016/j.jseaes.2015.07.005}, pages = {312 -- 327}, year = {2015}, abstract = {A tectonic slice of an arc sequence consisting of low-grade metavolcanic rocks and overlying metasedimentary succession is exposed in the Central Pontides north of the Izmir-Ankara-Erzincan suture separating Laurasia from Gondwana-derived terranes. The metavolcanic rocks mainly consist of basaltic andesite/andesite and mafic cognate xenolith-bearing rhyolite with their pyroclastic equivalents, which are interbedded with recrystallized pelagic limestone and chert. The metasedimentary succession comprises recrystallized micritic limestone with rare volcanogenic metaclastic rocks and stratigraphically overlies the metavolcanic rocks. The geochemistry of the metavolcanic rocks indicates an arc setting evidenced by depletion of HFSE (Ti, P and Nb) and enrichment of fluid mobile LILE. Identical trace and rare earth elements compositions of basaltic andesites/andesites and rhyolites suggest that they are cogenetic and derived from a common parental magma. The arc sequence crops out between an Albian-Turonian subduction-accretionary complex representing the Laurasian active margin and an ophiolitic melange. Absence of continent derived detritus in the arc sequence and its tectonic setting in a wide Cretaceous accretionary complex suggest that the Kosdag Arc was intra-oceanic. Zircons from two metarhyolite samples give Late Cretaceous (93.8 +/- 1.9 and 94.4 +/- 1.9 Ma) U/Pb ages. These ages are the same as the age of the supra-subduction ophiolites in western Turkey, which implies that that the Kosdag Arc may represent part of the incipient arc formed during the generation of the supra-subduction ophiolites. The low-grade regional metamorphism in the Kosdag Arc is constrained to 69.9 +/- 0.4 Ma by Ar-40/Ar-39 muscovite dating indicating that the arc sequence became part of a wide Tethyan Cretaceous accretionary complex by the latest Cretaceous. Non-collisional cessation of the arc volcanism is possibly associated with southward migration of the magmatism as in the Izu-Bonin-Mariana arc system. (c) 2015 Elsevier Ltd. All rights reserved.}, language = {en} } @book{SchwarzerWeissSaoumiKitteletal.2023, author = {Schwarzer, Ingo and Weiß-Saoumi, Said and Kittel, Roland and Friedrich, Tobias and Kaynak, Koraltan and Durak, Cemil and Isbarn, Andreas and Diestel, J{\"o}rg and Knittel, Jens and Franz, Marquart and Morra, Carlos and Stahnke, Susanne and Braband, Jens and Dittmann, Johannes and Griebel, Stephan and Krampf, Andreas and Link, Martin and M{\"u}ller, Matthias and Radestock, Jens and Strub, Leo and Bleeke, Kai and Jehl, Leander and Kapitza, R{\"u}diger and Messadi, Ines and Schmidt, Stefan and Schwarz-R{\"u}sch, Signe and Pirl, Lukas and Schmid, Robert and Friedenberger, Dirk and Beilharz, Jossekin Jakob and Boockmeyer, Arne and Polze, Andreas and R{\"o}hrig, Ralf and Sch{\"a}be, Hendrik and Thiermann, Ricky}, title = {RailChain}, number = {152}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-550-7}, issn = {1613-5652}, doi = {10.25932/publishup-57740}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-577409}, publisher = {Universit{\"a}t Potsdam}, pages = {140}, year = {2023}, abstract = {The RailChain project designed, implemented, and experimentally evaluated a juridical recorder that is based on a distributed consensus protocol. That juridical blockchain recorder has been realized as distributed ledger on board the advanced TrainLab (ICE-TD 605 017) of Deutsche Bahn. For the project, a consortium consisting of DB Systel, Siemens, Siemens Mobility, the Hasso Plattner Institute for Digital Engineering, Technische Universit{\"a}t Braunschweig, T{\"U}V Rheinland InterTraffic, and Spherity has been formed. These partners not only concentrated competencies in railway operation, computer science, regulation, and approval, but also combined experiences from industry, research from academia, and enthusiasm from startups. Distributed ledger technologies (DLTs) define distributed databases and express a digital protocol for transactions between business partners without the need for a trusted intermediary. The implementation of a blockchain with real-time requirements for the local network of a railway system (e.g., interlocking or train) allows to log data in the distributed system verifiably in real-time. For this, railway-specific assumptions can be leveraged to make modifications to standard blockchains protocols. EULYNX and OCORA (Open CCS On-board Reference Architecture) are parts of a future European reference architecture for control command and signalling (CCS, Reference CCS Architecture - RCA). Both architectural concepts outline heterogeneous IT systems with components from multiple manufacturers. Such systems introduce novel challenges for the approved and safety-relevant CCS of railways which were considered neither for road-side nor for on-board systems so far. Logging implementations, such as the common juridical recorder on vehicles, can no longer be realized as a central component of a single manufacturer. All centralized approaches are in question. The research project RailChain is funded by the mFUND program and gives practical evidence that distributed consensus protocols are a proper means to immutably (for legal purposes) store state information of many system components from multiple manufacturers. The results of RailChain have been published, prototypically implemented, and experimentally evaluated in large-scale field tests on the advanced TrainLab. At the same time, the project showed how RailChain can be integrated into the road-side and on-board architecture given by OCORA and EULYNX. Logged data can now be analysed sooner and also their trustworthiness is being increased. This enables, e.g., auditable predictive maintenance, because it is ensured that data is authentic and unmodified at any point in time.}, language = {en} } @article{TuckerBoehningGaeseFaganetal.2018, author = {Tucker, Marlee A. and Boehning-Gaese, Katrin and Fagan, William F. and Fryxell, John M. and Van Moorter, Bram and Alberts, Susan C. and Ali, Abdullahi H. and Allen, Andrew M. and Attias, Nina and Avgar, Tal and Bartlam-Brooks, Hattie and Bayarbaatar, Buuveibaatar and Belant, Jerrold L. and Bertassoni, Alessandra and Beyer, Dean and Bidner, Laura and van Beest, Floris M. and Blake, Stephen and Blaum, Niels and Bracis, Chloe and Brown, Danielle and de Bruyn, P. J. Nico and Cagnacci, Francesca and Calabrese, Justin M. and Camilo-Alves, Constanca and Chamaille-Jammes, Simon and Chiaradia, Andre and Davidson, Sarah C. and Dennis, Todd and DeStefano, Stephen and Diefenbach, Duane and Douglas-Hamilton, Iain and Fennessy, Julian and Fichtel, Claudia and Fiedler, Wolfgang and Fischer, Christina and Fischhoff, Ilya and Fleming, Christen H. and Ford, Adam T. and Fritz, Susanne A. and Gehr, Benedikt and Goheen, Jacob R. and Gurarie, Eliezer and Hebblewhite, Mark and Heurich, Marco and Hewison, A. J. Mark and Hof, Christian and Hurme, Edward and Isbell, Lynne A. and Janssen, Rene and Jeltsch, Florian and Kaczensky, Petra and Kane, Adam and Kappeler, Peter M. and Kauffman, Matthew and Kays, Roland and Kimuyu, Duncan and Koch, Flavia and Kranstauber, Bart and LaPoint, Scott and Leimgruber, Peter and Linnell, John D. C. and Lopez-Lopez, Pascual and Markham, A. Catherine and Mattisson, Jenny and Medici, Emilia Patricia and Mellone, Ugo and Merrill, Evelyn and Mourao, Guilherme de Miranda and Morato, Ronaldo G. and Morellet, Nicolas and Morrison, Thomas A. and Diaz-Munoz, Samuel L. and Mysterud, Atle and Nandintsetseg, Dejid and Nathan, Ran and Niamir, Aidin and Odden, John and Oliveira-Santos, Luiz Gustavo R. and Olson, Kirk A. and Patterson, Bruce D. and de Paula, Rogerio Cunha and Pedrotti, Luca and Reineking, Bjorn and Rimmler, Martin and Rogers, Tracey L. and Rolandsen, Christer Moe and Rosenberry, Christopher S. and Rubenstein, Daniel I. and Safi, Kamran and Said, Sonia and Sapir, Nir and Sawyer, Hall and Schmidt, Niels Martin and Selva, Nuria and Sergiel, Agnieszka and Shiilegdamba, Enkhtuvshin and Silva, Joao Paulo and Singh, Navinder and Solberg, Erling J. and Spiegel, Orr and Strand, Olav and Sundaresan, Siva and Ullmann, Wiebke and Voigt, Ulrich and Wall, Jake and Wattles, David and Wikelski, Martin and Wilmers, Christopher C. and Wilson, John W. and Wittemyer, George and Zieba, Filip and Zwijacz-Kozica, Tomasz and Mueller, Thomas}, title = {Moving in the Anthropocene}, series = {Science}, volume = {359}, journal = {Science}, number = {6374}, publisher = {American Assoc. for the Advancement of Science}, address = {Washington}, issn = {0036-8075}, doi = {10.1126/science.aam9712}, pages = {466 -- 469}, year = {2018}, abstract = {Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-range movements from areas with higher human impact. Global loss of vagility alters a key ecological trait of animals that affects not only population persistence but also ecosystem processes such as predator-prey interactions, nutrient cycling, and disease transmission.}, language = {en} }