@article{FroitzheimBergnerSchroeder2015,
  author    = {Froitzheim, Manuel and Bergner, Nadine and Schroeder, Ulrik},
  title     = {Android-Workshop zur Vertiefung der Kenntnisse bez{\"u}glich Datenstrukturen und Programmierung in der Studieneingangsphase},
  series = {HDI 2014 : Gestalten von {\"U}berg{\"a}ngen},
  volume    = {2015},
  journal   = {HDI 2014 : Gestalten von {\"U}berg{\"a}ngen},
  number    = {9},
  editor    = {Schwill, Andreas},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-80247},
  pages     = {11 -- 26},
  year      = {2015},
  abstract  = {Die Studieneingangsphase stellt f{\"u}r Studierende eine Schl{\"u}sselphase des terti{\"a}ren Ausbildungsabschnitts dar. Fachwissenschaftliches Wissen wird praxisfern vermittelt und die Studierenden k{\"o}nnen die Zusammenh{\"a}nge zwischen den Themenfeldern der verschiedenen Vorlesungen nicht erkennen. Zur Verbesserung der Situation wurde ein Workshop entwickelt, der die Verbindung der Programmierung und der Datenstrukturen vertieft. Dabei wird das Spiel Go-Moku1 als Android-App von den Studierenden selbst{\"a}ndig entwickelt. Die Kombination aus Software (Java, Android-SDK) und Hardware (Tablet-Computer) f{\"u}r ein kleines realistisches Softwareprojekt stellt f{\"u}r die Studierenden eine neue Erfahrung dar.},
  language  = {de}
}
@misc{MardoukhiJeonMetzler2015,
  author    = {Mardoukhi, Yousof and Jeon, Jae-Hyung and Metzler, Ralf},
  title     = {Geometry controlled anomalous diffusion in random fractal geometries},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {980},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-47486},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-474864},
  pages     = {30134 -- 30147},
  year      = {2015},
  abstract  = {We investigate the ergodic properties of a random walker performing (anomalous) diffusion on a random fractal geometry. Extensive Monte Carlo simulations of the motion of tracer particles on an ensemble of realisations of percolation clusters are performed for a wide range of percolation densities. Single trajectories of the tracer motion are analysed to quantify the time averaged mean squared displacement (MSD) and to compare this with the ensemble averaged MSD of the particle motion. Other complementary physical observables associated with ergodicity are studied, as well. It turns out that the time averaged MSD of individual realisations exhibits non-vanishing fluctuations even in the limit of very long observation times as the percolation density approaches the critical value. This apparent non-ergodic behaviour concurs with the ergodic behaviour on the ensemble averaged level. We demonstrate how the non-vanishing fluctuations in single particle trajectories are analytically expressed in terms of the fractal dimension and the cluster size distribution of the random geometry, thus being of purely geometrical origin. Moreover, we reveal that the convergence scaling law to ergodicity, which is known to be inversely proportional to the observation time T for ergodic diffusion processes, follows a power-law ∼T-h with h < 1 due to the fractal structure of the accessible space. These results provide useful measures for differentiating the subdiffusion on random fractals from an otherwise closely related process, namely, fractional Brownian motion. Implications of our results on the analysis of single particle tracking experiments are provided.},
  language  = {en}
}
@article{Gosset2015,
  author    = {Gosset, E.},
  title     = {Studies of WR+O colliding-wind binaries},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88247},
  pages     = {305 -- 308},
  year      = {2015},
  abstract  = {Two of the main physical parameters that govern the massive star evolution, the mass and the mass-loss rate, are still poorly determined from the observational point of view. Only binary systems could provide well constrained masses and colliding-wind binaries could bring some constraints on the mass-loss rate. Therefore, colliding-wind binaries turn out to be very promising objects. In this framework, we present detailed studies of basic observational data obtained with the XMM-Newton facility and combined with ground-based observations and other data. We expose the results for two particularly interesting WR+O colliding-wind binaries: WR22 and WR21a.},
  language  = {en}
}
@article{LaengrichSchulze2015,
  author    = {L{\"a}ngrich, Matthias and Schulze, J{\"o}rg},
  title     = {Angewandte Output-Orientierung},
  series = {HDI 2014 : Gestalten von {\"U}berg{\"a}ngen},
  volume    = {2015},
  journal   = {HDI 2014 : Gestalten von {\"U}berg{\"a}ngen},
  number    = {9},
  editor    = {Schwill, Andreas and Schubert, Sigrid},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-80299},
  pages     = {93 -- 107},
  year      = {2015},
  abstract  = {Erstsemester-Studierende sind mit den Anforderungen des Lehr-/ Lernprozess einer Universit{\"a}t oder Fachhochschule noch nicht vertraut. Ihre Erwartungen orientieren sich vielmehr an ihrer bisherigen Lerngeschichte (Abitur, Fachabitur, o. {\"a}.). Neben den fachlichen Anforderungen des ersten Semesters m{\"u}ssen die Studierenden also auch Ver{\"a}nderungen im Lehr-/Lernprozess erkennen und bew{\"a}ltigen. Es wird anhand einer Output-orientierten informatischen Lehrveranstaltung aufgezeigt, dass sich aus deren strengen Anforderungen der Messbarkeit klare Kompetenzbeschreibungen ergeben, die besonders dem Orientierungsbed{\"u}rfnis Erstsemester-Studierender entgegenkommen.},
  language  = {de}
}
@article{BibbySharaZureketal.2015,
  author    = {Bibby, J. and Shara, M. and Zurek, D. and Crowther, P. A. and Moffat, Anthony F. J. and Drissen, L. and Wilde, M.},
  title     = {The Distribution of Massive Stars in M101},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88402},
  pages     = {355},
  year      = {2015},
  abstract  = {75 WR stars and 164 RSGs are identified in a single WFC3 pointing of our M101 survey. We find that within it's large star-forming complex NGC 5462 WR stars are preferentially located in the core whilst RSGs are found in the halo, suggesting two bursts of star-formation. A review of our WR candidates reveals that only ∼30\% are detected in the archival broad-band ACS imaging whilst only ∼50\% are associated with HII regions.},
  language  = {en}
}
@article{SanyalMoriyaLanger2015,
  author    = {Sanyal, D. and Moriya, T. J. and Langer, N.},
  title     = {Envelope inflation in Wolf-Rayet stars and extended supernova shock breakout signals},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88062},
  pages     = {213 -- 216},
  year      = {2015},
  abstract  = {Massive, luminous stars reaching the Eddington limit in their interiors develop very dilute, extended envelopes. This effect is called envelope inflation. If the progenitors of Type Ib/c supernovae, which are believed to be Wolf-Rayet (WR) stars, have inflated envelopes then the shock breakout signals diffuse in them and can extend their rise times significantly. We show that our inflated, hydrogen-free, WR stellar models with a radius of ∼R⊙ can have shock breakout signals longer than ∼ 60 s. The puzzlingly long shock breakout signal observed in the Type Ib SN 2008D can be explained by an inflated progenitor envelope, and more such events might argue in favour of existence of inflated envelopes in general.},
  language  = {en}
}
@article{Bestenlehner2015,
  author    = {Bestenlehner, J. M.},
  title     = {Stellar parameters from photometric data for fainter and more distant Wolf-Rayet stars},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88390},
  pages     = {354},
  year      = {2015},
  abstract  = {Spectroscopy is the preferred way to study the physical and wind properties of Wolf-Rayet (WR) stars, but with decreasing brightness and increasing distance of the object spectroscopy become very expensive. However, photometry still delivers a high signal to noise ratio. Current and past astronomical surveys and space missions provide large data sets, that can be harvested to discover new WR stars and study them over a wide metallicity range with the help of state of the art stellar atmosphere and evolutionary models.},
  language  = {en}
}
@article{Crowther2015,
  author    = {Crowther, P. A.},
  title     = {Wolf-Rayet content of the Milky Way},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87562},
  pages     = {21 -- 26},
  year      = {2015},
  abstract  = {An overview of the known Wolf-Rayet (WR) population of the Milky Way is presented, including a brief overview of historical catalogues and recent advances based on infrared photometric and spectroscopic observations resulting in the current census of 642 (vl.13 online catalogue). The observed distribution of WR stars is considered with respect to known star clusters, given that ≤20\% of WR stars in the disk are located in clusters. WN stars outnumber WC stars at all galactocentric radii, while early-type WC stars are strongly biased against the inner Milky Way. Finally, recent estimates of the global WR population in the Milky Way are reassessed, with 1,200±100 estimated, such that the current census may be 50\% complete. A characteristic WR lifetime of 0.25 Myr is inferred for an initial mass threshold of 25 M⊙.},
  language  = {en}
}
@article{Weis2015,
  author    = {Weis, K.},
  title     = {Family ties of WR to LBV nebulae yielding clues for stellar evolution},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87949},
  pages     = {167 -- 170},
  year      = {2015},
  abstract  = {Luminous Blue Variables (LBVs) are stars is a transitional phase massive stars may enter while evolving from main-sequence to Wolf-Rayet stars. The to LBVs intrinsic photometric variability is based on the modulation of the stellar spectrum. Within a few years the spectrum shifts from OB to AF type and back. During their cool phase LBVs are close to the Humphreys-Davidson (equivalent to Eddington/Omega-Gamma) limit. LBVs have a rather high mass loss rate, with stellar winds that are fast in the hot and slower in the cool phase of an LBV. These alternating wind velocities lead to the formation of LBV nebulae by wind-wind interactions. A nebula can also be formed in a spontaneous giant eruption in which larger amounts of mass are ejected. LBV nebulae are generally small (< 5 pc) mainly gaseous circumstellar nebulae, with a rather large fraction of LBV nebulae being bipolar. After the LBV phase the star will turn into a Wolf-Rayet star, but note that not all WR stars need to have passed the LBV phase. Some follow from the RSG and the most massive directly from the MS phase. In general WRs have a large mass loss and really fast stellar winds. The WR wind may interact with winds of earlier phases (MS, RSG) to form WR nebulae. As for WR with LBV progenitors the scenario might be different, here no older wind is present but an LBV nebula! The nature of WR nebulae are therefore manifold and in particular the connection (or family ties) of WR to LBV nebulae is important to understand the transition between these two phases, the evolution of massive stars, their winds, wind-wind and wind-nebula interactions. Looking at the similarities and differences of LBV and WR nebula, figuring what is a genuine LBV and WR nebula are the basic question addressed in the analysis presented here.},
  language  = {en}
}
@article{Kueker2015,
  author    = {K{\"u}ker, Manfred},
  title     = {Magnetospheres of massive stars},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87864},
  pages     = {143 -- 146},
  year      = {2015},
  abstract  = {We study the interaction of line-driven winds from massive stars with the magnetic field rooted in these stars by carrying out numerical simulations using the Nirvana MHD code in 2D in spherical polar coordinates. The code's adaptive mesh refinement feature allows high spatial resolution across the whole simulation box. We study both O and Wolf-Rayet stars for a range of magnetic field strengths from weak to strong as measured by the confinement parameter. For weak fields our simulations show that the initially dipolar field opens up far away from the star and a thin disk-like structure forms in the equatorial plane of the magnetic field. For stronger fields the disk is disrupted close to the stellar surface and closed field lines persist at low latitudes. For very strong fields a pronounced magnetosphere forms where the gas is forced to move along the field lines and eventually falls back to the stellar surface.},
  language  = {en}
}
@article{FalcetaGoncalves2015,
  author    = {Falceta-Goncalves, D.},
  title     = {Magnetic fields, non-thermal radiation and particle acceleration in colliding winds of WR-O stars},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88211},
  pages     = {289 -- 292},
  year      = {2015},
  abstract  = {Non-thermal emission has been detected in WR-stars for many years at long wavelengths spectral range, in general attributed to synchrotron emission. Two key ingredients are needed to explain such emissions, namely magnetic fields and relativistic particles. Particles can be accelerated to relativistic speeds by Fermi processes at strong shocks. Therefore, strong synchrotron emission is usually attributed to WR binarity. The magnetic field may also be amplified at shocks, however the actual picture of the magnetic field geometry, intensity, and its role on the acceleration of particles at WR binary systems is still unclear. In this work we discuss the recent developments in MHD modelling of wind-wind collision regions by means of numerical simulations, and the coupled particle acceleration processes related.},
  language  = {en}
}
@article{DwarkadasRosenberg2015,
  author    = {Dwarkadas, Vikram V. and Rosenberg, D.},
  title     = {X-ray Emission from Ionized Wind-Bubbles around Wolf-Rayet Stars},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88301},
  pages     = {329 -- 332},
  year      = {2015},
  abstract  = {Using a code that employs a self-consistent method for computing the effects of photoionization on circumstellar gas dynamics, we model the formation of wind-driven nebulae around massive Wolf-Rayet (W-R) stars. Our algorithm incorporates a simplified model of the photo-ionization source, computes the fractional ionization of hydrogen due to the photoionizing flux and recombination, and determines self-consistently the energy balance due to ionization, photo-heating and radiative cooling. We take into account changes in stellar properties and mass-loss over the star's evolution. Our multi-dimensional simulations clearly reveal the presence of strong ionization front instabilities. Using various X-ray emission models, and abundances consistent with those derived for W-R nebulae, we compute the X-ray flux and spectra from our wind bubble models. We show the evolution of the X-ray spectral features with time over the evolution of the star, taking the absorption of the X-rays by the ionized bubble into account. Our simulated X-ray spectra compare reasonably well with observed spectra of Wolf-Rayet bubbles. They suggest that X-ray nebulae around massive stars may not be easily detectable, consistent with observations.∗},
  language  = {en}
}
@article{Huefner2015,
  author    = {H{\"u}fner, Klaus},
  title     = {Konzepte f{\"u}r die Neustrukturierung des Systems der Vereinten Nationen},
  series = {Konzepte f{\"u}r die Reform der Vereinten Nationen : 12. Potsdamer UNO-Konferenz am 28.Juni 2014},
  volume    = {2015},
  journal   = {Konzepte f{\"u}r die Reform der Vereinten Nationen : 12. Potsdamer UNO-Konferenz am 28.Juni 2014},
  number    = {11},
  editor    = {Zimmermann, Andreas},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-80147},
  pages     = {9 -- 28},
  year      = {2015},
  abstract  = {I. Einleitung II. Zum Ergebnisdokument des Weltgipfels vom September 2005 III. Alle 10 Jahre ein neuer Vorschlag zur Charta-Revision? IV. Schlussbemerkungen V Literatur},
  language  = {de}
}
@article{Baeriswyl2015,
  author    = {Baeriswyl, Pascale},
  title     = {Moderne Arbeitsmethoden f{\"u}r einen wirksameren UNO-Sicherheitsrat},
  series = {Konzepte f{\"u}r die Reform der Vereinten Nationen : 12. Potsdamer UNO-Konferenz am 28.Juni 2014},
  volume    = {2015},
  journal   = {Konzepte f{\"u}r die Reform der Vereinten Nationen : 12. Potsdamer UNO-Konferenz am 28.Juni 2014},
  number    = {11},
  editor    = {Zimmermann, Andreas},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-80159},
  pages     = {29 -- 47},
  year      = {2015},
  abstract  = {I. Der UNO-Sicherheitsrat: Work in Progress or in Regress? II. Geschichte der Arbeitsmethoden: Szenen und Akteure III. Arbeitsmechanik im Alltag: Mut zur Innovation! IV. Schlussfolgerung: Vom Kulturwandel zur Strukturreform?},
  language  = {de}
}
@article{Martens2015,
  author    = {Martens, Jens},
  title     = {Vom Konsultativstatus zu Stakeholder-Partnerschaften},
  series = {Konzepte f{\"u}r die Reform der Vereinten Nationen : 12. Potsdamer UNO-Konferenz am 28.Juni 2014},
  volume    = {2015},
  journal   = {Konzepte f{\"u}r die Reform der Vereinten Nationen : 12. Potsdamer UNO-Konferenz am 28.Juni 2014},
  number    = {11},
  editor    = {Zimmermann, Andreas},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-80163},
  pages     = {49 -- 67},
  year      = {2015},
  abstract  = {Die Beziehungen zwischen den Vereinten Nationen und nichtstaatlichen Akteuren haben seit den 1990er Jahren einen radikalen Wandel erlebt. Nach der Rio-Konferenz {\"u}ber Umwelt und Entwicklung 1992 stand in den Vereinten Nationen zun{\"a}chst die Frage im Vordergrund, wie der gewachsenen Bedeutung der Nichtregierungsorganisationen (NGOs) in der Arbeit und den Strukturen der Weltorganisation Rechnung getragen werden k{\"o}nnte. Seit Ende der 1990er Jahre dominierten innerhalb der Vereinten Nationen und einiger ihrer Spezialorgane und Sonderorganisationen zunehmend die Bem{\"u}hungen, Privatunternehmen und ihre Interessenvertreter aktiver in die Arbeit der Vereinten Nationen zu integrieren. Dies geschah zum einen in Form unterschiedlichster bilateraler Kontakte und Kooperationsvorhaben zwischen Unternehmen und UN-Akteuren, zum anderen im Rahmen von Dialogveranstaltungen und gemeinsamen Initiativen von Regierungen, zwischenstaatlichen Gremien, Wirtschaftsvertretern und NGOs, f{\"u}r die im Folgeprozess der Rio-Konferenz der Begriff der Multistakeholder-Partnerschaften gepr{\"a}gt wurde. Der folgende Beitrag nimmt diese Entwicklung kritisch unter die Lupe. Er zeichnet im Zeitraffer nach, wie sich die Beziehungen zwischen den Vereinten Nationen und nichtstaatlichen Akteuren gewandelt haben, beschreibt das Ausmaß und die Bandbreite der neuen Partnerschaftsans{\"a}tze, er{\"o}rtert Risiken und Nebenwirkungen dieses Paradigmenwechsels in der internationalen Politik und skizziert zum Schluss, welche Konsequenzen sich daraus f{\"u}r die Vereinten Nationen abzeichnen.},
  language  = {de}
}
@article{HeinzHomburger2015,
  author    = {Heinz, Wolfgang S. and Homburger, Zine},
  title     = {Die Rolle des UN-Hochkommissariats f{\"u}r Menschenrechte (OHCHR) im UN-Menschenrechtsschutz},
  series = {Konzepte f{\"u}r die Reform der Vereinten Nationen : 12. Potsdamer UNO-Konferenz am 28.Juni 2014},
  volume    = {2015},
  journal   = {Konzepte f{\"u}r die Reform der Vereinten Nationen : 12. Potsdamer UNO-Konferenz am 28.Juni 2014},
  number    = {11},
  editor    = {Zimmermann, Andreas},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-80177},
  pages     = {69 -- 98},
  year      = {2015},
  abstract  = {I. Gr{\"u}ndung, Aufgaben und Struktur des Hochkommissariats II. Zur Rolle des OHCHR im und gegen{\"u}ber dem Menschenrechtsrat III. Zu Erfolgschancen von Feldmissionen in eher schwierigen L{\"a}ndern: China, Russische F{\"o}deration, Afghanistan, Sudan und Kolumbien IV. Zur Frage der politischen Unabh{\"a}ngigkeit des OHCHR V. Schlussfolgerungen und Ausblick},
  language  = {de}
}
@article{BomansBeckerKleemannetal.2015,
  author    = {Bomans, Dominik J. and Becker, Andrew C. and Kleemann, B. and Weis, K. and Pasquali, A.},
  title     = {Luminous Wolf-Rayet stars at low metallicity},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87635},
  pages     = {51 -- 54},
  year      = {2015},
  abstract  = {The evolution of massive stars in very low metallicity galaxies is less well observationally constrained than in environments more similar to the Milky Way, M33, or the LMC. We discuss in this contribution the current state of our program to search for and characterize Wolf-Rayet stars (and other massive emission line stars) in low metallicity galaxies in the Local Volume.},
  language  = {en}
}
@article{KehrigVilchezPerezMonteroetal.2015,
  author    = {Kehrig, C. and V{\´i}lchez, J. M. and P{\´e}rez-Montero, E. and Iglesias-P{\´a}ramo, J. and Brinchmann, Jarle and Crowther, P. A. and Durret, F. and Kunth, D.},
  title     = {PopIII-star siblings in IZw18 and metal-poor WR galaxies unveiled from integral field spectroscopy},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87648},
  pages     = {55 -- 58},
  year      = {2015},
  abstract  = {Here, we highlight our recent results from the IFS study of Mrk178, the closest metal-poor WR galaxy, and of IZw18, the most metal-poor star-forming galaxy known in the local Universe. The IFS data of Mrk178 show the importance of aperture effects on the search for WR features, and the extent to which physical variations in the ISM properties can be detected. Our IFS data of IZw18 reveal its entire nebular HeIIλ4686-emitting region, and indicate for the very first time that peculiar, hot (nearly) metal-free ionizing stars (called here PopIII-star siblings) might hold the key to the HeII-ionization in IZw18.},
  language  = {en}
}
@article{SrivastavaKehrigKanthariaetal.2015,
  author    = {Srivastava, S. and Kehrig, C. and Kantharia, N. G. and P{\´e}rez-Montero, E. and V{\´i}lchez, J. M. and Iglesias-P{\´a}ramo, J. and Janardhan, P.},
  title     = {A 2D view of Wolf-Rayet Galaxies},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87650},
  pages     = {59 -- 62},
  year      = {2015},
  abstract  = {The main objective of this work is to investigate the evolution of massive stars, and the interplay between them and the ionized gas for a sample of local metal-poor Wolf-Rayet galaxies. Optical integral field spectrocopy was used in combination with multi-wavelength radio data. Combining optical and radio data, we locate Wolf-Rayet stars and supernova remnants across the Wolf-Rayet galaxies to study the spatial correlation between them. This study will shed light on the massive star formation and its feedback, and will help us to better understand distant star-forming galaxies.},
  language  = {en}
}
@article{Hillier2015,
  author    = {Hillier, D. J.},
  title     = {Spectrum formation in Wolf-Rayet stars},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87669},
  pages     = {65 -- 70},
  year      = {2015},
  abstract  = {We highlight the basic physics that allows fundamental parameters, such as the effective temperature, luminosity, abundances, and mass-loss rate, of Wolf-Rayet (W-R) stars to be determined. Since the temperature deduced from the spectrum of a W-R star is an ionization temperature, a detailed discussion of the ionization structure of W-R winds, and how it is set, is given. We also provide an overview of line and continuum formation in W-R stars. Mechanisms that contribute to the strength of different emission lines, such as collisional excitation, radiative recombination, dielectronic recombination, and continuum uorescence, are discussed.},
  language  = {en}
}
@article{EversbergAldorettaKnapenetal.2015,
  author    = {Eversberg, T. and Aldoretta, E. J. and Knapen, J. H. and Moffat, Anthony F. J. and Morel, T. and Ramiaramanantsoa, T. and Rauw, G. and Richardson, N. D. and St-Louis, N. and Teodoro, M.},
  title     = {World-wide amateur observations},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87705},
  pages     = {71 -- 74},
  year      = {2015},
  abstract  = {For some years now, spectroscopic measurements of massive stars in the amateur domain have been fulfilling professional requirements. Various groups in the northern and southern hemispheres have been established, running successful professional-amateur (ProAm) collaborative campaigns, e.g., on WR, O and B type stars. Today high quality data (echelle and long-slit) are regularly delivered and corresponding results published. Night-to-night long-term observations over months to years open a new opportunity for massive-star research. We introduce recent and ongoing sample campaigns (e.g. ∊ Aur, WR 134, ζ Pup), show respective results and highlight the vast amount of data collected in various data bases. Ultimately it is in the time-dependent domain where amateurs can shine most.},
  language  = {en}
}
@article{StLouis2015,
  author    = {St-Louis, N.},
  title     = {Studying Large and Small Scale Wind Asymmetries with Spectroscopy and Polarimetry},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87726},
  pages     = {79 -- 84},
  year      = {2015},
  abstract  = {In this paper, I review observational evidence from spectroscopy and polarimetry for the presence of small and large scale structure in the winds of Wolf-Rayet (WR) stars. Clumping is known to be ubiquitous in the winds of these stars and many of its characteristics can be deduced from spectroscopic time-series and polarisation lightcurves. Conversely, a much smaller fraction of WR stars have been shown to harbour larger scale structures in their wind (∼ 1/5) while they are thought to be present is the winds of most of their O-star ancestors. The reason for this difference is still unknown.},
  language  = {en}
}
@article{HoffmanLomax2015,
  author    = {Hoffman, J. L. and Lomax, J. R.},
  title     = {Structure and fate of binary WR stars},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87737},
  pages     = {85 -- 88},
  year      = {2015},
  abstract  = {Because most massive stars have been or will be affected by a companion during the course of their evolution, we cannot afford to neglect binaries when discussing the progenitors of supernovae and GRBs. Analyzing linear polarization in the emission lines of close binary systems allows us to probe the structures of these systems' winds and mass flows, making it possible to map the complex morphologies of the mass loss and mass transfer structures that shape their subsequent evolution. In Wolf-Rayet (WR) binaries, line polarization variations with orbital phase distinguish polarimetric signatures arising from lines that scatter near the stars from those that scatter far from the orbital plane. These far-scattering lines may form the basis for a "binary line-effect method" of identifying rapidly rotating WR stars (and hence GRB progenitor candidates) in binary systems.},
  language  = {en}
}
@article{CheneWyrickBorissovaetal.2015,
  author    = {Chen{\´e}, A.-N. and Wyrick, D. and Borissova, J. and Kuhn, M. and Herv{\´e}, A. and Ram{\´i}rez Alegr{\´i}a, S. and Bonatto, C. and Bouret, J.-C. and Kurtev, R.},
  title     = {Improving distances to Galactic Wolf-Rayet stars},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87759},
  pages     = {97 -- 100},
  year      = {2015},
  abstract  = {Before GAIA improves the HIPPARCOS survey, direct determination of the distance via parallax is only possible for γ Vel, but the analysis of the cluster or association to which WR stars are associated can give distances with a 50\% to a 10\% accuracy. The list of Galactic clusters, associations and clusters/association candidates has grown significantly in the last decade with the numerous deep, high resolution surveys of the Milky Way. In this work, we revisit the fundamental parameters of known clusters with WR stars, and we present the search for new ones. All our work is based on the catalogs from the VVV (from the VISTA telescope) and the UKIDS (from the UKIRT telescope) near infrared surveys. Finally, the relations between the fundamental parameters of clusters with WR stars are explored.},
  language  = {en}
}
@article{RossloweCrowtherClarketal.2015,
  author    = {Rosslowe, C. K. and Crowther, P. A. and Clark, J. S. and Negueruela, I.},
  title     = {Physical properties of the WR stars in Westerlund 1},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87779},
  pages     = {105 -- 108},
  year      = {2015},
  abstract  = {The Westerlund 1 (Wd1) cluster hosts a rich and varied collection of massive stars. Its dynamical youth and the absence of ongoing star formation indicate a coeval population. As such, the simultaneous presence of both late-type supergiants and Wolf-Rayet stars has defied explanation in the context of single-star evolution. Observational evidence points to a high binary fraction, hence this stellar population offers a robust test for stellar models accounting for both single-star and binary evolution. We present an optical to near-IR (VLT \& NTT) spectroscopic analysis of 22 WR stars in Wd 1, delivering physical properties for the WR stars. We discuss how these differ from the Galactic field population, and how they may be reconciled with the predictions of single and binary evolutionary models.},
  language  = {en}
}
@article{Arthur2015,
  author    = {Arthur, S. J.},
  title     = {Wolf-Rayet nebulae and the wind-interstellar medium interaction},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88267},
  pages     = {315 -- 320},
  year      = {2015},
  abstract  = {I review our current understanding of the interaction between a Wolf-Rayet star's fast wind and the surrounding medium, and discuss to what extent the predictions of numerical simulations coincide with multiwavelength observations of Wolf-Rayet nebulae. Through a series of examples, I illustrate how changing the input physics affects the results of the numerical simulations. Finally, I discuss how numerical simulations together with multiwavelength observations of these objects allow us to unpick the previous mass-loss history of massive stars.},
  language  = {en}
}
@article{ReyesPerezMorissetPenaetal.2015,
  author    = {Reyes-P{\´e}rez, J. and Morisset, C. and Pena, M. and Mesa-Delgado, A.},
  title     = {A consistent spectral model of WR 136 and its associated bubble NGC 6888},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88274},
  pages     = {321 -- 324},
  year      = {2015},
  abstract  = {We analyse whether a stellar atmosphere model computed with the code CMFGEN provides an optimal description of the stellar observations of WR 136 and simultaneously reproduces the nebular observations of NGC 6888, such as the ionization degree, which is modelled with the pyCloudy code. All the observational material available (far and near UV and optical spectra) were used to constrain such models. We found that the stellar temperature T∗, at τ = 20, can be in a range between 70 000 and 110 000 K, but when using the nebula as an additional restriction, we found that the stellar models with T∗ ∼ 70 000 K represent the best solution for both, the star and the nebula.},
  language  = {en}
}
@article{NajarrodelaFuenteGeballeetal.2015,
  author    = {Najarro, F. and de la Fuente, D. and Geballe, T. R. and Figer, D. F. and Hillier, D. J.},
  title     = {The WR population in the Galactic Center},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87794},
  pages     = {113 -- 116},
  year      = {2015},
  abstract  = {The Galactic Center (GC) hosts three of the most massive WR rich, resolved young clusters in the Local Group as well as a large number of apparently isolated massive stars. Therefore, it constitutes a test bed to study the star formation history of the region, to probe a possible top-heavy scenario and to address massive star formation (clusters vs isolation) in such a dense and harsh environment. We present results from our ongoing infrared spectroscopic studies of WRs and other massive stars at the Center of the Milky Way.},
  language  = {en}
}
@article{HamaguchiCorcoran2015,
  author    = {Hamaguchi, K. and Corcoran, M. F.},
  title     = {Extremely Hard X-ray Emission from η Car Observed with XMM-Newton and NuSTAR around Periastron in 2014.6},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87926},
  pages     = {159 -- 162},
  year      = {2015},
  abstract  = {The super massive binary system, η Car, experienced periastron passage in the summer of 2014. We observed the star twice around the maximum (forb =0.97, 2014 June 6) and just before the minimum (ϕorb =0.99, 2014 July 28) of its wind-wind colliding (WWC) X-ray emis-sion using the XMM-Newton and NuSTAR observatories, the latter of which is equipped with extremely hard X-ray (>10 keV) focusing mirrors. In both observations, NuSTAR detected the thermal X-ray tail up to 40-50 keV. The hard slope is consistent with an electron tem- perature of ∼6 keV, which is significantly higher than the ionization temperature (kT ∼4 keV) measured from the Fe K emission lines, assuming collisional equilibrium plasma. The spectrum did not show a hard power-law component above this energy range, unlike earlier detections with INTEGRAL and Suzaku. In the second NuSTAR observation, the X-ray flux above 5 keV declined gradually in ∼1 day. This result suggests that the WWC apex was gradually hidden behind the optically thick primary wind around conjunction.},
  language  = {en}
}
@article{EldridgeMcClellandXiaoetal.2015,
  author    = {Eldridge, J. J. and McClelland, L. A. S. and Xiao, L. and Stanway, E. R. and Bray, J.},
  title     = {The importance of getting single-star and binary physics correct},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-87966},
  pages     = {177 -- 182},
  year      = {2015},
  abstract  = {We discuss the uncertainties that need to be considered when creating numerical models of WR stars. We pay close attention to inflation and duplicity of the stellar models, highlighting several observational tests that show these are key to understanding WR stellar populations.},
  language  = {en}
}
@article{McClellandEldridge2015,
  author    = {McClelland, L. A. S. and Eldridge, J. J.},
  title     = {Helium stars},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88010},
  pages     = {197 -- 200},
  year      = {2015},
  abstract  = {There are outstanding problems in trying to reproduce the observed nature of Wolf-Rayet stars from theoretical stellar models. We have investigated the effects of uncertainties, such as composition and mass-loss rate, on the evolution and structure of Wolf-Rayet stars and their lower mass brethren. We find that the normal Conti scenario needs to be altered, with different WR types being due to different initial masses as well as different stages of evolution.},
  language  = {en}
}
@article{GrassitelliLangerSanyaletal.2015,
  author    = {Grassitelli, L. and Langer, N. and Sanyal, D. and Fossati, Luca and Bestenlehner, J. M.},
  title     = {Instabilities in the envelope of Wolf-Rayet stars},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88024},
  pages     = {201 -- 204},
  year      = {2015},
  abstract  = {Wolf-Rayet stars are very hot stars close to the Eddington limit. In the conditions encountered in their radiation pressure dominated outer layers several instabilities are expected to arise. These instabilities could influence both the dynamic of their optically thick winds and the observed spectral lines introducing small and large scale variability. We investigate the conditions in the convective envelopes of our helium star models and relate them to the appearance of a high number of stochastic density inhomogeneities, i.e. clumping in the optically thick wind. We also investigate the pulsational stability of these envelope, considering the effect of the high stellar wind mass loss rates.},
  language  = {en}
}
@article{ShachamIdanShaviv2015,
  author    = {Shacham, T. and Idan, I. and Shaviv, N. J.},
  title     = {A new mechanism for long long-term pulsations of hot stars?},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88058},
  pages     = {209 -- 212},
  year      = {2015},
  abstract  = {We suggest several ideas which when combined could lead to a new mechanism for long-term pulsations of very hot and luminous stars. These involve the interplay between convection, radiation, atmospheric clumping and winds, which collectively feed back to stellar expansion and contraction. We discuss these ideas and point out the future work required in order to fill in the blanks.},
  language  = {en}
}
@article{VanbeverenMennekens2015,
  author    = {Vanbeveren, D. and Mennekens, N.},
  title     = {Massive star population synthesis with binaries},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88071},
  pages     = {217 -- 224},
  year      = {2015},
  abstract  = {We first give a short historical overview with some key facts of massive star population synthesis with binaries. We then discuss binary population codes and focus on two ingredients which are important for massive star population synthesis and which may be different in different codes. Population simulations with binaries is the third part where we consider the initial massive binary frequency, the RSG/WR and WC/WN and SNII/SNIbc number ratio's, the probable initial rotational velocity distribution of massive stars.},
  language  = {en}
}
@article{MunozMoffatHilletal.2015,
  author    = {Munoz, M. and Moffat, Anthony F. J. and Hill, G. M. and Richardson, N. D. and Pablo, H.},
  title     = {The missing Wolf-Rayet X-ray binary systems},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88082},
  pages     = {225 -- 228},
  year      = {2015},
  abstract  = {We investigate the rarity of the Wolf-Rayet X-ray binaries (WRXRBs) in contrast to their predecessors, the high mass X-ray binaries (HMXRBs). Recent studies suggest that common envelope (CE) mergers during the evolution of a HMXRBs may be responsible (Linden et al. 2012). We conduct a binary population synthesis to generate a population of HMXRBs mimicking the Galactic sample and vary the efficiency parameter during the CE phase to match the current WRXRB to HMXRB ratio. We find that ∼50\% of systems must merge to match observational constraints.},
  language  = {en}
}
@article{GeorgyEkstroemHirschietal.2015,
  author    = {Georgy, C. and Ekstr{\"o}m, S. and Hirschi, R. and Meynet, G. and Groh, J. H. and Eggenberger, P.},
  title     = {Wolf-Rayet stars as an evolved stage of stellar life},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88097},
  pages     = {229 -- 232},
  year      = {2015},
  abstract  = {Wolf-Rayet (WR) stars, as they are advanced stages of the life of massive stars, provide a good test for various physical processes involved in the modelling of massive stars, such as rotation and mass loss. In this paper, we show the outputs of the latest grids of single massive stars computed with the Geneva stellar evolution code, and compare them with some observations. We present a short discussion on the shortcomings of single stars models and we also briefly discuss the impact of binarity on the WR populations.},
  language  = {en}
}
@article{WoffordCharlotEldridge2015,
  author    = {Wofford, A. and Charlot, S. and Eldridge, J. J.},
  title     = {Properties of LEGUS Clusters Obtained with Different Massive-Star Evolutionary Tracks},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88109},
  pages     = {233 -- 236},
  year      = {2015},
  abstract  = {We compute spectral libraries for populations of coeval stars using state-of-the-art massive-star evolutionary tracks that account for different astrophysics including rotation and close-binarity. Our synthetic spectra account for stellar and nebular contributions. We use our models to obtain E(B - V ), age, and mass for six clusters in spiral galaxy NGC 1566, which have ages of < 50 Myr and masses of > 5 x 104M⊙ according to standard models. NGC 1566 was observed from the NUV to the I-band as part of the imaging Treasury HST program LEGUS: Legacy Extragalactic UV Survey. We aim to establish i) if the models provide reasonable fits to the data, ii) how well the models and photometry are able to constrain the cluster properties, and iii) how different the properties obtained with different models are.},
  language  = {en}
}
@article{WalshMonrealIberoVilchezetal.2015,
  author    = {Walsh, J. R. and Monreal-Ibero, A. and V{\´i}lchez, J. M. and P{\´e}rez-Montero, E. and Iglesias-P{\´a}ramo, J. and Sandin, C. and Relano, M. and Amor{\´i}n, R.},
  title     = {The Wolf-Rayet Population and ISM Interaction in Nearby Starbursts},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88339},
  pages     = {341 -- 344},
  year      = {2015},
  abstract  = {The interaction between massive star formation and gas is a key ingredient in galaxy evolution. Given the level of observational detail currently achievable in nearby starbursts, they constitute ideal laboratories to study interaction process that contribute to global evolution in all types of galaxies. Wolf-Rayet (WR) stars, as an observational marker of high mass star formation, play a pivotal role and their winds can strongly influence the surrounding gas. Imaging spectroscopy of two nearby (<4 Mpc) starbursts, both of which show multiple regions with WR stars, are discussed. The relation between the WR content and the physical and chemical properties of the surrounding ionized gas is explored.},
  language  = {en}
}
@article{GormazMatamalaHerveCheneetal.2015,
  author    = {Gormaz-Matamala, A. C. and Herv{\´e}, A. and Chen{\´e}, A.-N. and Cur{\´e}, M. and Mennickent, R. E.},
  title     = {Results Of The Spectroscopic Analysis Of WR6 Using CMFGEN},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88422},
  pages     = {357},
  year      = {2015},
  abstract  = {Using ESPaDOnS optical spectra of WR6, we search variations on the stellar wind parameters during the different phases of the spectral variations. We use the radiative transfer code CMFGEN (Hillier \& Miller 1998) to determine the wind parameters. Our work gives mean parameters for WR6, Teff = 55 kK, M = 2.7 × 10^-5 M⊙/yr and v∞ =1700 km/s. Furthermore the line profiles variations at different phases are the consequence of a variation of mass loss rate and temperature un the winds. Effective temperature reaches 59 kK at the highest intensity, whereas the mass-loss rate decreases to 2.5 × 10^-5 M⊙/yr in that case. On the other hand, effective temperature decreases to 52.5 kK and the mass-loss rate increases to 3 × 10^-5 M/⊙yr when the line profile reach its minimum intensity. Results confirm the variable nature of the stellar wind, presented in this case on two of its fundamental parameters: temperature and mass-loss; which could be used to constrain the nature of the instability at the basis of the wind.},
  language  = {en}
}
@article{KanarekSharaFahertyetal.2015,
  author    = {Kanarek, G. and Shara, M. and Faherty, J. and Zurek, D. and Moffat, Anthony F. J.},
  title     = {New Galactic Wolf-Rayet Stars},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88448},
  pages     = {359},
  year      = {2015},
  abstract  = {Over the course of 6 months in 2013, we observed nearly 400 Wolf-Rayet candidates in the Galactic plane. Preliminary results from this dataset are presented.},
  language  = {en}
}
@article{SugawaraTsuboiMaedaetal.2015,
  author    = {Sugawara, Y. and Tsuboi, Y. and Maeda, Y. and Pollock, A. M. T. and Williams, P. M.},
  title     = {The Swift monitoring of the colliding wind binary WR 21a},
  series = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  journal   = {Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.-5. June 2015},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-88517},
  pages     = {366},
  year      = {2015},
  abstract  = {The X-ray observations of the colliding wind binary WR 21a is reported. The first monitoring performed by Swift/XRT in order to reveal the phase-locked variation. Our observations cover 201 different epochs from 2013 October 1 to 2015 January 30 for a total exposure of about 306 ks. It is found for the first time that the luminosity varies roughly in inverse proportion to the separation of the two stars before the X-ray maximum but later drops rapidly toward periastron.},
  language  = {en}
}
@article{EngbringKlar2015,
  author    = {Engbring, Dieter and Klar, Tilman-Mathies},
  title     = {Medienbildung mit Informatik-Anteilen!?},
  series = {HDI 2014 : Gestalten von {\"U}berg{\"a}ngen},
  volume    = {2015},
  journal   = {HDI 2014 : Gestalten von {\"U}berg{\"a}ngen},
  number    = {9},
  editor    = {Schubert, Sigrid and Schwill, Andreas},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-84693},
  pages     = {125 -- 142},
  year      = {2015},
  abstract  = {Auf der Grundlage der Planung, Durchf{\"u}hrung, Evaluation und Revision eines gemeinsamen Seminars von Medienp{\"a}dagogik und Didaktik der Informatik stellen wir in diesem Aufsatz dar, wo die Defizite klassischer Medienbildung in Bezug auf digitale bzw. interaktive Medien liegen und welche Inhalte der Informatik f{\"u}r Studierende aller Lehr{\"a}mter - im allgemeinbildenden Sinne - aus dieser Perspektive relevant erscheinen.},
  language  = {de}
}
@article{KujathSchuetze2015,
  author    = {Kujath, Bertold and Sch{\"u}tze, Christopher},
  title     = {Evaluation der Lernwirksamkeit eines Lehrvideos zum informatischen Probleml{\"o}sen},
  series = {HDI 2014 : Gestalten von {\"U}berg{\"a}ngen},
  volume    = {2015},
  journal   = {HDI 2014 : Gestalten von {\"U}berg{\"a}ngen},
  number    = {9},
  editor    = {Schubert, Sigrid and Schwill, Andreas},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-84705},
  pages     = {143 -- 152},
  year      = {2015},
  abstract  = {Der folgende Artikel beschreibt die Evaluation eines Lehrvideos zum informatischen Probleml{\"o}sen, welches auf der Grundlage einer Vergleichsstudie mit starken und schwachen Probleml{\"o}sern entwickelt wurde. Beispielhaft wird in dem Film ein F{\"a}rbeproblem durch einen fiktiven Hochleister unter lautem Denken gel{\"o}st, die einzelnen Arbeitsschritte werden abschnittsweise kommentiert und erkl{\"a}rt. Ob dieses Lernkonzept von Studenten akzeptiert wird und sich durch Anschauen des Videos tats{\"a}chlich ein Lerneffekt einstellt, wurde durch eine Befragung und eine erste Vergleichsstudie untersucht.},
  language  = {de}
}
@article{FietkauKindsmuellerGoettel2015,
  author    = {Fietkau, Julian and Kindsm{\"u}ller, Martin Christof and G{\"o}ttel, Timo},
  title     = {Rapid Prototyping von Interaktionskonzepten in der universit{\"a}ren MCI-Lehre},
  series = {HDI 2014 : Gestalten von {\"U}berg{\"a}ngen},
  volume    = {2015},
  journal   = {HDI 2014 : Gestalten von {\"U}berg{\"a}ngen},
  number    = {9},
  editor    = {Schubert, Sigrid and Schwill, Andreas},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-84718},
  pages     = {153 -- 160},
  year      = {2015},
  abstract  = {In der Lehre zur MCI (Mensch-Computer-Interaktion) stellt sich immer wieder die Herausforderung, praktische {\"U}bungen mit spannenden Ergebnissen durchzuf{\"u}hren, die sich dennoch nicht in technischen Details verlieren sondern MCI-fokussiert bleiben. Im Lehrmodul „Interaktionsdesign" an der Universit{\"a}t Hamburg werden von Studierenden innerhalb von drei Wochen prototypische Interaktionskonzepte f{\"u}r das Spiel Neverball entworfen und praktisch umgesetzt. Anders als in den meisten Grundlagenkursen zur MCI werden hier nicht Mock-Ups, sondern lauff{\"a}hige Software entwickelt. Um dies innerhalb der Projektzeit zu erm{\"o}glichen, wurde Neverball um eine TCP-basierte Schnittstelle erweitert. So entf{\"a}llt die aufw{\"a}ndige Einarbeitung in den Quellcode des Spiels und die Studierenden k{\"o}nnen sich auf ihre Interaktionsprototypen konzentrieren. Wir beschreiben die Erfahrungen aus der mehrmaligen Durchf{\"u}hrung des Projektes und erl{\"a}utern unser Vorgehen bei der Umsetzung. Die Ergebnisse sollen Lehrende im Bereich MCI unterst{\"u}tzen, {\"a}hnliche praxisorientierte {\"U}bungen mit Ergebnissen „zum Anfassen" zu gestalten.},
  language  = {de}
}
@article{BergnerTaraschewskiSchroeder2015,
  author    = {Bergner, Nadine and Taraschewski, Christian and Schroeder, Ulrik},
  title     = {Beispiel eines Sch{\"u}lerwettbewerbs zum Thema Projektmanagement und App-Programmierung},
  series = {HDI 2014 : Gestalten von {\"U}berg{\"a}ngen},
  volume    = {2015},
  journal   = {HDI 2014 : Gestalten von {\"U}berg{\"a}ngen},
  number    = {9},
  editor    = {Schubert, Sigrid and Schwill, Andreas},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-84726},
  pages     = {161 -- 168},
  year      = {2015},
  abstract  = {Es wird ein Informatik-Wettbewerb f{\"u}r Sch{\"u}lerinnen und Sch{\"u}ler der Sekundarstufe II beschrieben, der {\"u}ber mehrere Wochen m{\"o}glichst realit{\"a}tsnah die Arbeitswelt eines Informatikers vorstellt. Im Wettbewerb erarbeiten die Sch{\"u}lerteams eine Android-App und organisieren ihre Entwicklung durch Projektmanagementmethoden, die sich an professionellen, agilen Prozessen orientieren. Im Beitrag werden der theoretische Hintergrund zu Wettbewerben, die organisatorischen und didaktischen Entscheidung, eine erste Evaluation sowie Reflexion und Ausblick dargestellt.},
  language  = {de}
}
@article{LewinMcNicol2015,
  author    = {Lewin, Cathy and McNicol, Sarah},
  title     = {Supporting the Development of 21st Century Skills through ICT},
  series = {KEYCIT 2014 - Key Competencies in Informatics and ICT},
  journal   = {KEYCIT 2014 - Key Competencies in Informatics and ICT},
  number    = {7},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {1868-0844},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82672},
  pages     = {181 -- 198},
  year      = {2015},
  abstract  = {The growing impact of globalisation and the development of a 'knowledge society' have led many to argue that 21st century skills are essential for life in twenty-first century society and that ICT is central to their development. This paper describes how 21st century skills, in particular digital literacy, critical thinking, creativity, communication and collaboration skills, have been conceptualised and embedded in the resources developed for teachers in iTEC, a four-year, European project. The effectiveness of this approach is considered in light of the data collected through the evaluation of the pilots, which considers both the potential benefits of using technology to support the development of 21st century skills, but also the challenges of doing so. Finally, the paper discusses the learning support systems required in order to transform pedagogies and embed 21st century skills. It is argued that support is required in standards and assessment; curriculum and instruction; professional development; and learning environments.},
  language  = {en}
}
@article{MagenheimNellesNeugebaueretal.2015,
  author    = {Magenheim, Johannes and Nelles, Wolfgang and Neugebauer, Jonas and Ohrndorf, Laura and Schaper, Niclas and Schubert, Sigrid},
  title     = {Expert Rating of Competence Levels in Upper Secondary Computer Science Education},
  series = {KEYCIT 2014 - Key Competencies in Informatics and ICT},
  journal   = {KEYCIT 2014 - Key Competencies in Informatics and ICT},
  number    = {7},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {1868-0844},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82683},
  pages     = {199 -- 216},
  year      = {2015},
  abstract  = {In the project MoKoM, which is funded by the German Research Foundation (DFG) from 2008 to 2012, a test instrument measuring students' competences in computer science was developed. This paper presents the results of an expert rating of the levels of students' competences done for the items of the instrument. At first we will describe the difficulty-relevant features that were used for the evaluation. These were deduced from computer science, psychological and didactical findings and resources. Potentials and desiderata of this research method are discussed further on. Finally we will present our conclusions on the results and give an outlook on further steps.},
  language  = {en}
}
@article{OpelKramerTrommenetal.2015,
  author    = {Opel, Simone and Kramer, Matthias and Trommen, Michael and Pottb{\"a}cker, Florian and Ilaghef, Youssef},
  title     = {BugHunt},
  series = {KEYCIT 2014 - Key Competencies in Informatics and ICT},
  journal   = {KEYCIT 2014 - Key Competencies in Informatics and ICT},
  number    = {7},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {1868-0844},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82693},
  pages     = {217 -- 233},
  year      = {2015},
  abstract  = {Competencies related to operating systems and computer security are usually taught systematically. In this paper we present a different approach, in which students have to remove virus-like behaviour on their respective computers, which has been induced by software developed for this purpose. They have to develop appropriate problem-solving strategies and thereby explore essential elements of the operating system. The approach was implemented exemplarily in two computer science courses at a regional general upper secondary school and showed great motivation and interest in the participating students.},
  language  = {en}
}
@article{PassigTzurielKedmi2015,
  author    = {Passig, David and Tzuriel, David and Kedmi, Ganit Eshel},
  title     = {Improving children's Cognitive Modifiability through Mediated Learning and Dynamic Assessment within 3D Immersive Virtual Reality Environment},
  series = {KEYCIT 2014 - Key Competencies in Informatics and ICT},
  journal   = {KEYCIT 2014 - Key Competencies in Informatics and ICT},
  number    = {7},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {1868-0844},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82705},
  pages     = {235 -- 252},
  year      = {2015},
  abstract  = {The objectives of this study were to examine (a) the effect of dynamic assessment (DA) in a 3D Immersive Virtual Reality (IVR) environment as compared with computerized 2D and noncomputerized (NC) situations on cognitive modifiability, and (b) the transfer effects of these conditions on more difficult problem solving administered two weeks later in a non-computerized environment. A sample of 117 children aged 6:6-9:0 years were randomly assigned into three experimental groups of DA conditions: 3D, 2D, and NC, and one control group (C). All groups received the pre- and post-teaching Analogies subtest of the Cognitive Modifiability Battery (CMB-AN). The experimental groups received a teaching phase in conditions similar to the pre-and post-teaching phases. The findings showed that cognitive modifiability, in a 3D IVR, was distinctively higher than in the two other experimental groups (2D computer group and NC group). It was also found that the 3D group showed significantly higher performance in transfer problems than the 2D and NC groups.},
  language  = {en}
}
@article{Saito2015,
  author    = {Saito, Toshinori},
  title     = {The Key Competencies in Informatics and ICT viewed from Nussbaum's Ten Central Capabilities},
  series = {KEYCIT 2014 - Key Competencies in Informatics and ICT},
  journal   = {KEYCIT 2014 - Key Competencies in Informatics and ICT},
  number    = {7},
  publisher = {Universit{\"a}tsverlag Potsdam},
  address   = {Potsdam},
  issn      = {1868-0844},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82718},
  pages     = {253 -- 266},
  year      = {2015},
  abstract  = {This article shows a discussion about the key competencies in informatics and ICT viewed from a philosophical foundation presented by Martha Nussbaum, which is known as 'ten central capabilities'. Firstly, the outline of 'The Capability Approach', which has been presented by Amartya Sen and Nussbaum as a theoretical framework of assessing the state of social welfare, will be explained. Secondly, the body of Nussbaum's ten central capabilities and the reason for being applied as the basis of discussion will be shown. Thirdly, the relationship between the concept of 'capability' and 'competency' is to be discussed. After that, the author's assumption of the key competencies in informatics and ICT led from the examination of Nussbaum's ten capabilities will be presented.},
  language  = {en}
}