TY - GEN A1 - Mardoukhi, Yousof A1 - Jeon, Jae-Hyung A1 - Metzler, Ralf T1 - Geometry controlled anomalous diffusion in random fractal geometries BT - looking beyond the infinite cluster T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - 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. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 980 KW - plasma-membrane KW - mechanisms KW - motion KW - nonergodicity KW - models Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-474864 SN - 1866-8372 IS - 980 SP - 30134 EP - 30147 ER - TY - JOUR A1 - Stillmark, Hans-Christian ED - Langner, Paul Martin ED - Mirecka, Agata T1 - Perturbation als Analysemethode dramatischer Texte BT - Dramaturgien der "Störung" bei Bertolt Brecht und Heiner Müller JF - Tendenzen der zeitgenössischen Dramatik N2 - Perturbation als Analysemethode für dramatische Texte wird hier am Beispiel von Brecht und Müller ausprobiert. KW - Perturbation KW - Dramatik KW - Brecht KW - Heiner Müller Y1 - 2015 SN - 978-3-631-65597-9 SP - 11 EP - 29 PB - Lang-Ed. CY - Frankfurt, M. ER - TY - JOUR A1 - Haßler, Gerda ED - McElvenny, James T1 - ‘Communicating the past to the present’ BT - Is anachronism inevitable? Desirable? JF - History and Philosophy of the Language Sciences KW - anachronism KW - conceptual history KW - Ferdinand de Saussure KW - linguistic historiography KW - Plato´s Cratylus KW - salon KW - word order Y1 - 2015 UR - http://hiphilangsci.net/2015/06/03/salon-anachronism-in-linguistic-historiography SN - 2366-2409 ER - TY - GEN A1 - Tremblay, Jean Christophe A1 - Blanco-Rey, Maria T1 - Manipulating interfacial hydrogens at palladium via STM N2 - In this contribution, we provide a detailed dynamical analysis of the interfacial hydrogen migration mediated by scanning tunneling microscopy (STM). Contributions from the STM-current and from the non-adiabatic couplings are taken into account using only first principle models. The slight asymmetry of the tunnelling rates with respect to the potential bias sign inferred from experimental observations is reproduced by weighting the contributions of the metal acceptor–donor states for the propagation of the impinging electrons. The quasi-thermal inelastic collision mechanism is treated perturbatively. The influence of hydrogen pre-coverage is also investigated using new potential energy surfaces obtained from periodic density functional theory calculations. Fully quantum dynamical simulations of the system evolution are performed by solving the Pauli master equation, providing insight into the reaction mechanism of STM manipulation of subsurface hydrogens. It is observed that the hydrogen impurity favors resurfacing over occupation of the bulk and subsurface sites whenever possible. The present simulations give strong indication that the experimentally observed protuberances after STM-excitation are due to hydrogen accumulating in the vicinity of the surface. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 291 Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-99511 ER - TY - JOUR A1 - Volger, Helmut T1 - Die Stärkung der Vertragsorgane im UN-Menschenrechtssystem JF - MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen N2 - I. Das UN-Menschenrechtsschutzsystem II. Die Menschenrechtsvertragsorgane III. Das System der Menschenrechtsvertragsorgane in der Praxis IV. Die Reform der Vertragsorgane V. Der Abschluss des Reformprozesses: Resolution 68/268 VI. Fazit Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-94938 SN - 1434-2820 VL - 20 IS - 2 SP - 107 EP - 116 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Richter, Dagmar T1 - Recht des Tieres und menschliche Interessen JF - MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen N2 - I. Einführung II. Die Kreaturwürde im schweizerischen Recht – Entstehung und Konzeption III. Inhalt und Bedeutung der Kreaturwürde IV. Die besondere Herausforderung: Würde der Pflanze V. Kreaturwürde und Menschenwürde VI. Kreaturwürde in der Gentechnologie VII. Kreaturwürde im Tierschutz VIII. Reflexion Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-94926 SN - 1434-2820 VL - 20 IS - 2 SP - 97 EP - 106 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Schmitz, Friederike T1 - Tierschutz, Tierrechte oder Tierbefreiung? JF - MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen N2 - I. Einleitung II. Ethik III. Moralische Tierrechte? IV. Die Nutzung von Tieren V. Ethik und politische Theorie der Nutztierhaltung VI. Tierrechte oder Tierbefreiung? Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-94912 SN - 1434-2820 VL - 20 IS - 2 SP - 87 EP - 96 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Ladwig, Bernd T1 - Warum manche Tiere Rechte haben - und wir nicht die einzigen sind JF - MenschenRechtsMagazin : MRM ; Informationen, Meinungen, Analysen N2 - In diesem Text soll zweierlei gezeigt werden. Erstens, weil Menschen Rechte haben, gibt es wenigstens einige Tiere, die Rechte haben (I.). Zweitens, wir können die Rechte von Tieren nicht willkürfrei auf die Art begrenzen, die wir selber bilden; Menschen sind nicht die einzigen Tiere, die Rechte haben (II.). Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-94900 SN - 1434-2820 VL - 20 IS - 2 SP - 75 EP - 86 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Blankenstein, David A1 - Savoy, Bénédicte T1 - Frontale Präsenz BT - zu einem unbekannten Porträt Alexander von Humboldts im Besitz des französischen Conseil d’État JF - HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies N2 - Ein bislang unveröffentlichtes Porträt Alexander von Humboldts aus der Hand Frédéric d’Houdetots, ein Schüler des Malers Jacques-Louis David, bereichert die Humboldt-Ikonographie um eine Darstellung, die den berühmten Reisenden und Gelehrten als jungen Mann, wenige Jahre nach seiner Rückkehr aus Amerika zeigt – beeindruckend lebendig, fokussiert und präsent. Das 1807 während der Franzosenzeit in Berlin entstandene Porträt verweist als Teil eines im Conseil d’État in Paris aufbewahrten Porträt-Albums auf die Zirkel und Beziehungen, die sich in der besetzten preußischen Hauptstadt zwischen Besatzern, jüdischen Salonkreisen und der wissenschaftlichen Community gebildet haben, ein Nährboden für den transnationalen Austausch von Vertretern einer jungen und vitalen Generation, die sich als echte Europäer verstanden. N2 - Un portrait jusqu’à présent inédit d’Alexander von Humboldt par Frédéric d’Houdetot, élève de Jacques-Louis David, enrichit l’iconographie humboldtienne d’une effigie qui donne à voir le célèbre voyageur et érudit en jeune homme, quelques années seulement après son retour des Amériques – un portrait qui frappe par sa vitalité, sa concentration et la forte présence du savant. Dessiné dans le contexte de l’occupation de Berlin par l’armée napoléonienne et conservé au Conseil d’Etat à Paris, ce portrait est issu d’un album réunissant un grand nombre d’autres portraits de Berlinois des années 1800, qui témoigne des relations étroites que l’occupant put entretenir avec les représentants de l’élite juifs de la ville et la communauté scientifique, dans une dynamique propice aux échanges transnationaux d’une génération jeune, vitale et profondément européenne. N2 - A previously unreleased portrait of Alexander von Humboldt, drawn by Jacques-Louis David’s disciple Frédéric d’Houdetot, adds a lively, focused and astonishingly present image to the iconography of Humboldt, that of the famous traveler and scholar as a young man, a few years after his return from the Americas. The effigy, traced in 1807 Berlin during the French occupation, is part of an album of portraits by Houdetot conserved in the Conseil d’État in Paris and throws some light upon the relationships that formed in the Prussian capital between members of the occupying forces, Jewish salon circles and the scientific community – a breeding ground for the transnational exchange of representatives of a young and vital generation that saw themselves as true Europeans. KW - Ikonographie KW - Frédéric d’Houdetot KW - Conseil d’État KW - besetztes Preußen KW - Preußen und Frankreich Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-89012 SN - 1617-5239 SN - 2568-3543 VL - XVI IS - 31 SP - 107 EP - 114 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Erdmann, Dominik A1 - Weber, Jutta T1 - Nachlassgeschichten BT - Bemerkungen zu Humboldts nachgelassenen Papieren in der Berliner Staatsbibliothek und der Biblioteka Jagiellońska Krakau JF - HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies N2 - Der Artikel schildert die Geschichte verschiedener Teile des Manuskriptnachlasses Alexander von Humboldts, die sich heute in der Staatsbibliothek zu Berlin – Preußischer Kulturbesitz (SBB) und in der Biblioteka Jagiellońska in Krakau (BJ) befinden. Dabei wird insbesondere auf den unterschiedlichen ‚Quellenwert‘ der drei großen Nachlassabteilungen – der amerikanischen Reisetagebücher, der Kollektaneen zum Kosmos (beide SBB) und dem sogenannten Nachlass Alexander von Humboldt (BJ) – eingegangen. N2 - The article discusses the history of different parts of Alexander von Humboldt’s estate which are kept today in the Berlin State Library (SBB) and the Jageillonian Library in Krakow (BJ). The general aim of the article is to show that – due to the specific history of each part of the handed-down papers – the three main sections of the Humboldt estate – the travel-journals from the American voyage, the Collectanea for the Kosmos (both SBB) and the so called Nachlass Alexander von Humboldt (BJ) – have a very different status as a historical source. N2 - Le présent article cherche à retracer l’histoire des différents fonds de manuscrits issus de la succession d’Alexandre de Humboldt, aujourd’hui reparti entre la Bibliothèque d’État de Berlin (SBB) et la Bibliothèque Jagiellonne de Cracovie. Le but général de l’article est de démontrer qu’en raison de leur histoire respective, les trois principaux fonds de la succession – les journaux de voyage américains, les Collectanées du Kosmos (tous deux SBB) et le dit Nachlass Alexander von Humboldt (BJ) – ont chacun une valeur très distincte comme source historique. KW - amerikanische Reisetagebücher KW - Humboldts Nachlass KW - Kollektaneen KW - Kosmos KW - Staatsbibliothek zu Berlin – Preußischer Kulturbesitz KW - Biblioteka Jagiellońska Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88997 SN - 1617-5239 SN - 2568-3543 VL - XVI IS - 31 SP - 60 EP - 79 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Kraft, Tobias T1 - Humboldts Hefte BT - Geschichte und Gegenwart von Tagebuch-Forschung und -Rezeption JF - HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies N2 - Der 2013 geglückte Ankauf der Amerikanischen Tagebücher durch ein Konsortium öffentlicher und privater Geldgeber hat es nicht nur ermöglicht, Alexander von Humboldts Reisemanuskripte zum ersten Mal einer breiten interessierten Öffentlichkeit vorzustellen, sondern wirft auch ein besonderer Licht auf die Geschichte ihrer Rezeption und Erforschung. Welche Phasen der Arbeit und Auswertung der Tagebücher lassen sich nachzeichnen? Und an welchem Punkt steht die Humboldt-Forschung in dieser Frage heute? N2 - La compra de los diarios del viaje americano, efectuada en 2013 por un consorcio de donadores públicos y privados, no sólo permitió presentar los manuscritos del viaje de Alejandro de Humboldt por primera vez a un público más grande, sino también arroja nueva luz sobre la historia de su recepción e investigación. El artículo pone énfasis en los siguientes puntos: ¿Cuáles han sido las fases del trabajo con los diarios y de su evaluación? ¿Y en qué punto estamos hoy en los estudios sobre Humboldt? N2 - The 2013 purchase of the American Travel Journals through a joint effort of public and private donors has not only given the general public a chance to see Alexander von Humboldt’s original manuscripts. It has also shed a new light on the history of their reception and the research related to their content. The article distuinguishes different stages of work with and analysis of the journals and reflects upon their relevance for today’s research on Alexander von Humboldt. KW - amerikanische Reisetagebücher KW - Rezeptionsgeschichte KW - Editionsgeschichte KW - DDR-Forschung KW - Alexander von Humboldt-Forschungsstelle Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88986 SN - 1617-5239 SN - 2568-3543 VL - XVI IS - 31 SP - 49 EP - 59 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Bispinck-Roßbacher, Julia T1 - „Zwischen den Zeilen …“ BT - zur kodikologischen Untersuchung der Amerikanischen Reisetagebücher von Alexander von Humboldt JF - HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies N2 - Der Artikel beschäftigt sich mit dem kodikologischen Befund der Amerikanischen Reisetagebücher und materialtechnologischen Untersuchungen zu ihrem Papier und Beschreibstoffen. Der kodikologische Aspekt beinhaltet eine umfassende Erfassung aller physischen Merkmale und Besonderheiten der Tagebücher, wobei ein Fokus auf die Zusammenstellung der Lagen, auf heraus getrennten oder ganz fehlenden Seiten liegt. Dies geschieht vor dem Hintergrund, die ursprüngliche Zusammenstellung der Tagebücher zu rekonstruieren, die Genese zu erforschen und im Nachlass befindliche Teile ggf. fehlenden Blättern oder Fragmenten in den Tagebüchern zuzuordnen. Wasserzeichenaufnahmen mit der Thermographiekamera und Tintenanlaysen mithilfe der Röntgenfluoreszenztechnik können dabei helfen aufzuzeigen, wie die Tagebücher entstanden sind und wie sie bis zum Tod Alexander von Humboldts von ihm als Arbeitsinstrument genutzt wurden. N2 - El artículo trata de los resultados codicológicos y exámenes tecnológicos sobre los aspectos materiales (papeles, tintas) de los Diarios del viaje americano. El aspecto codicológico incluye una revisión extensa de las características y particularidades materiales de los diarios, enfocando las encuadernaciones y las páginas separadas o faltantes. La revisión tiene como fin de reconstruir la compilación original de los diarios, de explorar su génesis y de adjudicar partes (fragmentos, folios faltantes) del legado a los diarios tal como los tenemos hoy. Las marcas de agua se registran con la cámara termográfica, el análisis de las tintas usadas se realiza con ayuda de un sistema de medida por fluorescencia de rayos X. Esto contribuirá a mostrar como evolucionaron los diarios de viaje y como fueron usadas por Alejandro de Humboldt a lo largo de su vida y hasta antes de su muerte. N2 - The American Travel Diaries’ paper and writing materials have been examined under codicological aspects as well as in terms of material based technologies. The report on the codicology includes a comprehensive survey of all physical features and specifics within the diaries. The examination is focused on the structure of the gatherings and cut-out or missing leafs. This is done in order to reconstruct the original compilation of the diaries, to research on their genesis and to possibly allocate parts of the bequest to missing pages or fragments in the diaries. Images taken of watermarks with the help of a thermographical camera and the analysis of the inks with the X-ray fluorescence method can help to show how the Travel Diaries were created in the first place and how they have been used by Alexander von Humboldt as a continuous working-tool until his death. KW - amerikanische Reisetagebücher KW - Kodikologie KW - Materialwissenschaften KW - Lagenaufstellung KW - Wasserzeichen KW - Tintenanalysen Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88978 SN - 1617-5239 SN - 2568-3543 VL - XVI IS - 31 SP - 43 EP - 48 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Bredekamp, Horst T1 - Die Amerikanischen Reisetagebücher BT - ein erster Zugang JF - HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies N2 - Die Reisetagebücher der Amerika-Reise (1799-1804) stellen ein Kompendium an schriftlichen Einträgen, Tabellen, Diagrammen und Zeichnungen dar, das in der Tradition römischer Papiermuseen des 17. Jhs. steht. Sie können als Mikrokosmen kleiner Kunstkammern aufgefasst werden, in denen Naturobjekte, Kunstwerke und Arbeitsmittel einen gemeinsamen Reflexionsraum bilden. Im Zentrum des vorliegenden Beitrags steht Humboldts Auffassung einer gestalteten Bestimmung von Landschaft vermittels besonders einprägsamer Bildformen. Auf erstaunliche Weise nähert sich Humboldts Ästhetik der Gesamtsicht von Natur Charles Darwins Begriff der natürlichen Schönheit an. In den Reisetagebüchern zeigt sich ein heterogener, von Lebendigkeit zeugender Charakter, der sowohl durch das unterschiedliche Format der einzelnen Hefte, als auch durch die inkonsistente Behandlung des Papiers erreicht wird. Dieser bewegliche Zug setzt sich in zahlreichen Zetteln, Briefen und weiteren Texten fort als ein eigenes Prinzip von Evolution. N2 - The travel diaries of Humboldt’s journey to the Americas (1799-1804) form a corpus of research in the form of written entries, tables, diagrams and sketches and serve as a continuation of the Roman “paper museums” of the 17th century. They can be seen as microcosms of small Kunstkammern (cabinets of curiosity) in which specimens from nature, artworks and working materials are documented and presented together in a common space for reflection and contemplation. The focus of this paper is Humboldt’s conception of a “designed determination” through particularly memorable images and forms. His aesthetic of an overall vision of nature bears a striking similarity to Charles Darwin’s theory of natural beauty. His travel diaries reveal a heterogeneous character, imbued with a vibrancy that is attained through both the various formats of different notebooks, as well as by the inconsistent treatment of the of the booklet’s paper. In the form of countless notes, letters and further texts, this dynamic process establishes the framework for its own principal of evolution. N2 - I Reisetagebücher („diari di viaggio“) scrisse durante il suo viaggio in America del Sud (1799-1804) costituiscono un compendio di annotazioni scritte, tabelle, diagrammi e disegni, che appare legato alla tradizione dei musei cartacei romani del Settecento. Questi diari possono essere considerati delle Kunstkammern in miniatura, in cui oggetti della natura, opere d’arte e strumenti di lavoro formano uno spazio di riflessione comune. Al centro dell’attenzione del presente contributo è l’idea humboldtiana di una determinazione del paesaggio attraverso immagini particolarmente facili da ricordare. In modo sorprendente, la riflessione estetica di Humboldt sul panorama naturale si avvicina all’idea di bellezza della natura di Charles Darwin. I Reisetagebücher mostrano un carattere eterogeneo e vivo, che si manifesta sia nel diverso formato dei quaderni, sia attraverso il trattamento inconsistente della carta. Questa dinamicità continua poi nei numerosi foglietti, nelle lettere, e in altri testi di Humboldt, e costituisce il principio di evoluzione a loro proprio. KW - amerikanische Reisetagebücher KW - Kunstgeschichte KW - Bildwissenschaft KW - Landschaft KW - Charles Darwin Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88963 SN - 1617-5239 SN - 2568-3543 VL - XVI IS - 31 SP - 26 EP - 42 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Schwarz, Ingo T1 - „etwas hervorzubringen, was meines Königs und meines Vaterlandes werth sein kann“ BT - Briefe von Alexander von Humboldt an Friedrich Wilhelm III., 1805 JF - HiN : Alexander von Humboldt im Netz ; International Review for Humboldtian Studies KW - Briefwechsel KW - Friedrich Wilhelm III. KW - König von Preußen KW - Italien KW - wissenschaftliche Sammlungen KW - Wilhelm von Humboldt Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88904 SN - 1617-5239 SN - 2568-3543 VL - XVI IS - 31 SP - 5 EP - 20 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Pflüger, Georg A. ED - Bauer, Hartmut ED - Büchner, Christiane ED - Markmann, Friedrich T1 - Erfahrungsbericht der Schulgenossenschaft F. W. Raiffeisen- Schule e. G. Wetzlar JF - Schulen im kommunalen Bildungsmanagement Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88648 SP - 149 EP - 155 ER - TY - JOUR A1 - Thies, Heike ED - Bauer, Hartmut ED - Büchner, Christiane ED - Markmann, Friedrich T1 - Kooperationsoptionen zwischen öffentlichen und privaten Schulen BT - Chancen und Probleme JF - Schulen im kommunalen Bildungsmanagement Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88637 SP - 135 EP - 148 ER - TY - JOUR A1 - Große, Gerrit ED - Bauer, Hartmut ED - Büchner, Christiane ED - Markmann, Friedrich T1 - Privatschulen in der kommunalen Bildungslandschaft JF - Schulen im kommunalen Bildungsmanagement Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88626 SP - 129 EP - 133 ER - TY - JOUR A1 - Rombey, Wolfgang ED - Bauer, Hartmut ED - Büchner, Christiane ED - Markmann, Friedrich T1 - Erfolgsfaktoren einer kommunalen Bildungslandschaft BT - Eine Handreichung zum Aufbau eines kommunalen Bildungsnetzwerkes JF - Schulen im kommunalen Bildungsmanagement Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88604 SP - 100 EP - 126 ER - TY - JOUR A1 - Kluth, Winfried ED - Bauer, Hartmut ED - Büchner, Christiane ED - Markmann, Friedrich T1 - Rechtliche Rahmenbedingungen für interkommunale Kooperation im Schulsektor JF - Schulen im kommunalen Bildungsmanagement Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88592 SP - 83 EP - 98 ER - TY - JOUR A1 - Glittenberg, Barbara ED - Bauer, Hartmut ED - Büchner, Christiane ED - Markmann, Friedrich T1 - E-Learning BT - Erfahrungen und Perspektiven JF - Schulen im kommunalen Bildungsmanagement Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88581 SP - 67 EP - 80 ER - TY - JOUR A1 - Wichmann, Maren ED - Bauer, Hartmut ED - Büchner, Christiane ED - Markmann, Friedrich T1 - Zukunftsmodell Ganztagsschule JF - Schulen im kommunalen Bildungsmanagement Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88548 SP - 27 EP - 42 ER - TY - JOUR A1 - Sugawara, Y. A1 - Tsuboi, Y. A1 - Maeda, Y. A1 - Pollock, A. M. T. A1 - Williams, P. M. T1 - The Swift monitoring of the colliding wind binary WR 21a JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - 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. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88517 SP - 366 ER - TY - JOUR A1 - Ro, S. A1 - Matzner, C. D. T1 - Envelope Inflation or Stellar Wind? JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - We an optically-thick, transonic, steady wind model for a H-free Wolf-Rayet star. A bifurcation is found across a critical mass loss rate Mb. Slower winds M < Mb extend by several hydrostatic stellar radii, reproduce features of envelope in ation from Petrovic et al. (2006) and Gräfener et al. (2012), and are energetically unbound. This work is of particular interest for extended envelopes and winds, radiative hydrodynamic instabilities (eg. wind stagnation, clumping, etc.), and NLTE atmospheric models. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88491 SP - 364 ER - TY - JOUR A1 - Reyes-Iturbide, J. A1 - Velázquez, Pablo F. A1 - Rosado, M. T1 - 3D numerical model for NGC 6888 Nebula JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - We present 3D numerical simulations of the NGC6888 nebula considering the proper motion and the evolution of the star, from the red supergiant (RSG) to the Wolf-Rayet (WR) phase. Our simulations reproduce the limb-brightened morphology observed in [OIII] and X-ray emission maps. The synthetic maps computed by the numerical simulations show filamentary and clumpy structures produced by instabilities triggered in the interaction between the WR wind and the RSG shell. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88485 SP - 363 ER - TY - JOUR A1 - Ramírez Alegría, S. A1 - Chené, A.-N. A1 - Borissova, J. A1 - Kurtev, R. A1 - Navarro, C. A1 - Kuhn, M. A1 - Carballo-Bello, J. A. T1 - A not so massive cluster hosting a very massive star JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - We present the first physical characterization of the young open cluster VVVCL041. We spectroscopically observed the cluster main-sequence stellar population and a very-massive star candidate: WR62-2. CMFGEN modelling to our near-infrared spectra indicates that WR62-2 is a very luminous (10^6.4±0.2 L⊙)and massive (∼ 80M⊙) star. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88477 SP - 362 ER - TY - JOUR A1 - Maryeva, O. A1 - Polcaro, V. F. A1 - Rossi, C. A1 - Viotti, R. T1 - Modeling of spectral variability of Romano's star JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - We present results of investigation of spectral variability of one of the most interesting massive stars, Romano's star (M33/V532 or GR290), located in the M33 galaxy. Brightness of the star changes together with its spectral class, which varies from WN11 to WN8. Using CMFGEN code we estimated parameters of stellar atmosphere and found that during last ten years bolometric luminosity of the star changed synchronously with stellar magnitude. Our calculations argue in favor of the hypothesis of a post-LBV status of GR290. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88462 SP - 361 ER - TY - JOUR A1 - Kochiashvili, N. A1 - Beradze, S. A1 - Kochiashvili, I. A1 - Natsvlishvili, R. A1 - Vardosanidze, M. T1 - New Photometric Observations of P Cygni JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - We present the results of the new photometric observations of the famous hypergiant PCygni. New observations were obtained in 2014 using the 48 cm Cassegrain telescope of the Abastumani Astrophysical Observatory, Georgia. We reveal some interesting behaviors of the B,V,R,I light curves, and also report new results on the periodicity of PCygni's variation. The latter result is based on the analysis of the photometric data (U,B,V filters) collected at the Abastumani Observatory between 1937 and 1983. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88452 SP - 360 ER - TY - JOUR A1 - Kanarek, G. A1 - Shara, M. A1 - Faherty, J. A1 - Zurek, D. A1 - Moffat, Anthony F. J. T1 - New Galactic Wolf-Rayet Stars JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - 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. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88448 SP - 359 ER - TY - JOUR A1 - Gormaz-Matamala, A. C. A1 - Hervé, A. A1 - Chené, A.-N. A1 - Curé, M. A1 - Mennickent, R. E. T1 - Results Of The Spectroscopic Analysis Of WR6 Using CMFGEN JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - 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. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88422 SP - 357 ER - TY - JOUR A1 - Calderón, D. A1 - Ballone, A. A1 - Cuadra, J. A1 - Schartmann, M. A1 - Burkert, Andreas A1 - Gillessen, S. T1 - Formation of the infalling Galactic Centre cloud G2 by collision of stellar winds JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - The gas cloud G2 is currently being tidally disrupted by the Galactic Centre super-massive black hole, Sgr A*. The region around the black hole is populated by ∼ 30 Wolf-Rayet stars, which produce strong outflows. Here we explore the possibility that gas clumps like G2 originate from the collision of stellar winds via the non-linear thin shell instability. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88412 SP - 356 ER - TY - JOUR A1 - Bibby, J. A1 - Shara, M. A1 - Zurek, D. A1 - Crowther, P. A. A1 - Moffat, Anthony F. J. A1 - Drissen, L. A1 - Wilde, M. T1 - The Distribution of Massive Stars in M101 JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - 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. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88402 SP - 355 ER - TY - JOUR A1 - Bestenlehner, J. M. T1 - Stellar parameters from photometric data for fainter and more distant Wolf-Rayet stars JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - 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. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88390 SP - 354 ER - TY - JOUR A1 - Beradze, S. A1 - Kochiashvili, N. A1 - Natsvlishvili, R. A1 - Kochiashvili, I. A1 - Janiashvili, E. A1 - Urushadze, T. A1 - Vardosanidze, M. T1 - P Cygni and its Observations at the Abastumani Observatory JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - We found original observations of PCygni by E. Kharadze and N. Magalashvili in the archives of the Abastumani Observatory. These observations were carried out in the period 1951–1983. Initially they used 29 Cygni as a comparison star, and all observations of PCygni were processed using this star. On the basis of their calculations, the authors decided that PCygni may be a WUMa type binary with an orbital period of 0.500565 d, but this hypothesis was not confirmed. The only observations that have been published in the Bulletin of the Abastumani Astrophysical Observatory were those of of 1951–1955. There are whole sets of observational data not only for PCygni and 29 Cygni, but in the majority of cases also for 36 Cygni in the archives. We recalculated all data (where it was possible) using 36 Cygni as a comparison star. We are presenting UBV light curves of the variable, and also observations made by V. Nikonov in Abastumani in the period 1935–1937 Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88389 SP - 353 ER - TY - JOUR A1 - Conti, P. S. T1 - Concluding Remarks JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - Selected remarks concerning Wolf-Rayet (W-R) stars in the framework of this workshop are given. The rich history of international conferences over the past four or so decades is summarized, important issues concerning W-R stars are considered, and some outstanding problems are reviewed. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88347 SP - 347 EP - 350 ER - TY - JOUR A1 - Walsh, J. R. A1 - Monreal-Ibero, A. A1 - Vílchez, J. M. A1 - Pérez-Montero, E. A1 - Iglesias-Páramo, J. A1 - Sandin, C. A1 - Relano, M. A1 - Amorín, R. T1 - The Wolf-Rayet Population and ISM Interaction in Nearby Starbursts JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - 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. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88339 SP - 341 EP - 344 ER - TY - JOUR A1 - Sokal, K. R. A1 - Johnson, K. E. A1 - Massey, P. A1 - Indebetouw, R. T1 - The importance of Wolf-Rayet ionization and feedback on super star cluster evolution JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - The feedback from massive stars is important to super star cluster (SSC) evolution and the timescales on which it occurs. SSCs form embedded in thick material, and eventually, the cluster is cleared out and revealed at optical wavelengths – however, this transition is not well understood. We are investigating this critical SSC evolutionary transition with a multi-wavelength observational campaign. Although previously thought to appear after the cluster has fully removed embedding natal material, we have found that SSCs may host large populations of Wolf-Rayet stars. These evolved stars provide ionization and mechanical feedback that we hypothesize is the tipping point in the combined feedback processes that drive a SSC to emerge. Utilizing optical spectra obtained with the 4m Mayall Telescope at Kitt Peak National Observatory and the 6.5m MMT, we have compiled a sample of embedded SSCs that are likely undergoing this short-lived evolutionary phase and in which we confirm the presence of Wolf-Rayet stars. Early results suggest that WRs may accelerate the cluster emergence. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88325 SP - 337 EP - 340 ER - TY - JOUR A1 - Toalá, Jesús Alberto A1 - Guerrero, Martín A. A1 - Chu, Y.-H. A1 - Arthur, S. J. A1 - Gruendl, R. A. T1 - Diffuse X-ray Emission within Wolf-Rayet Nebulae JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - We discuss our most recent findings on the diffuse X-ray emission within Wolf-Rayet (WR) nebulae. The best-quality X-ray observations of these objects are those performed by XMM- Newton and Chandra towards S 308, NGC 2359, and NGC 6888. Even though these three WR nebulae might have different formation scenarios, they all share similar characteristics: i) the main plasma temperatures of the X-ray-emitting gas is found to be T =[1–2]×^K, ii) the diffuse X-ray emission is confined inside the [O iii] shell, and iii) their X-ray luminosities and electron densities in the 0.3–2.0 keV energy range are LX ≈10^33–10^34 erg s-1 and ne ≈0.1–1 cm^-3 . These properties and the nebular-like abundances of the hot gas suggest mixing and/or thermal conduction is taking an important rôle reducing the temperature of the hot bubble. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88316 SP - 333 EP - 336 ER - TY - JOUR A1 - Dwarkadas, Vikram V. A1 - Rosenberg, D. T1 - X-ray Emission from Ionized Wind-Bubbles around Wolf-Rayet Stars JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - 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.∗ Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88301 SP - 329 EP - 332 ER - TY - JOUR A1 - Mesa-Delgado, A. A1 - Esteban, C. A1 - García-Rojas, J. T1 - Ring Nebulae BT - Tracers of the CNO Nucleosynthesis JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - Preliminary results are presented from spectroscopic data in the optical range of the Galactic ring nebulae NGC 6888, G2:4+1:4, RCW 58 and Sh2-308. Deep observations with long exposure times were carried out at the 6.5m Clay Telescope and at the 10.4m Gran Telescopio Canarias. In NGC 6888, recombination lines of C ii, O ii and N ii are detected with signal-to-noise ratios higher than 8. The chemical content of NGC 6888 is discussed within the chemical enrichment predicted by evolution models of massive stars. For all nebulae, a forthcoming work will content in-depth details about observations, analysis and final results (Esteban et al. 2015, in prep.). Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88299 SP - 325 EP - 328 ER - TY - JOUR A1 - Reyes-Pérez, J. A1 - Morisset, C. A1 - Pena, M. A1 - Mesa-Delgado, A. T1 - A consistent spectral model of WR 136 and its associated bubble NGC 6888 JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - 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. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88274 SP - 321 EP - 324 ER - TY - JOUR A1 - Arthur, S. J. T1 - Wolf-Rayet nebulae and the wind-interstellar medium interaction JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - 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. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88267 SP - 315 EP - 320 ER - TY - JOUR A1 - Russell, C. M. P. A1 - Corcoran, M. F. A1 - Cuadra, J. A1 - Owocki, S. P. A1 - Wang, Q. D. A1 - Hamaguchi, K. A1 - Sugawara, Y. A1 - Pollock, A. M. T. A1 - Kallman, T. R. T1 - Hydrodynamic and radiative transfer modeling of X-ray emission from colliding WR winds BT - WR 140 & the Galactic center JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - Colliding Wolf-Rayet (WR) winds produce thermal X-ray emission widely observed by X-ray telescopes. In wide WR+O binaries, such as WR 140, the X-ray flux is tied to the orbital phase, and is a direct probe of the winds’ properties. In the Galactic center, ~30 WRs orbit the super massive black hole (SMBH) within ~10”, leading to a smorgasbord of wind-wind collisions. To model the X-ray emission of WR 140 and the Galactic center, we perform 3D hydrodynamic simulations to trace the complex gaseous flows, and then carry out 3D radiative transfer calculations to compute the variable X-ray spectra. The model WR 140 RXTE light curve matches the data well for all phases except the X-ray minimum associated with periastron, while the model spectra agree with the RXTE hardness ratio and the shape of the Suzaku observations throughout the orbit. The Galactic center model of the Chandra flux and spectral shape match well in the region r ≤ 3”, but the model flux falls off too rapidly beyond this radius. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88255 SP - 309 EP - 312 ER - TY - JOUR A1 - Gosset, E. T1 - Studies of WR+O colliding-wind binaries JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - 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. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88247 SP - 305 EP - 308 ER - TY - JOUR A1 - Falceta-Goncalves, D. T1 - Magnetic fields, non-thermal radiation and particle acceleration in colliding winds of WR-O stars JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - 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. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88211 SP - 289 EP - 292 ER - TY - JOUR A1 - Mohamed, S. A1 - Mackey, J. A1 - Langer, N. A1 - Podsiadlowski, Ph. T1 - Shaping the outflows of Wolf-Rayet stars JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - Wolf-Rayet (WR) stars lose copious amounts of mass and momentum through dense stellar winds. The interaction of these outflows with their surroundings results in highly structured and complex circumstellar environments, often featuring knots, arcs, shells and spirals. Recent improvements in computational power and techniques have led to the development of detailed, multi-dimensional simulations that have given new insight into the origin of these structures, and better understanding of the physical mechanisms driving their formation. We review three of the main mechanisms that shape the outflows of WR stars: • interaction with the interstellar medium (ISM), i.e., wind-ISM interactions; • interaction with a stellar wind, either from a previous phase of evolution or the wind from a companion star, i.e., wind-wind interactions; • and interaction with a companion star that has a weak or insignificant outflow (e.g., a compact companion such as a neutron star or black hole), i.e.,wind-companion interactions. We also highlight the broader implications and impact of these circumstellar structures for related phenomena, e.g., for X-ray binaries and Gamma-ray bursts. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88200 SP - 283 EP - 288 ER - TY - JOUR A1 - Hendrix, T. A1 - Keppens, R. T1 - Modelling colliding wind binaries in 2D JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - We look at how the dynamics of colliding wind binaries (CWB) can be investigated in 2D, and how several parameters influence the dynamics of the small scale structures inside the colliding wind and the shocked regions, as well as in how the dynamics influence the shape of the collision region at large distances. The parameters we adopt are based on the binary system WR98a, one of the few Wolf-Rayet (WR) dusty pinwheels known. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88198 SP - 279 EP - 282 ER - TY - JOUR A1 - Williams, P. M. A1 - van der Hucht, K. A. T1 - The colliding-wind WC9+OB system WR 65 and dust formation by WR stars JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - Observations of the WC9+OB system WR65 in the infrared show variations of its dust emission consistent with a period near 4.8 yr, suggesting formation in a colliding-wind binary (CWB) having an elliptical orbit. If we adopt the IR maximum as zero phase, the times of X-ray maximum count and minimum extinction to the hard component measured by Oskinova & Hamann fall at phases 0.4–0.5, when the separation of the WC9 and OB stars is greatest. We consider WR65 in the context of other WC8–9+OB stars showing dust emission. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88188 SP - 275 EP - 278 ER - TY - JOUR A1 - Cherchneff, I. T1 - Dust formation in carbon-rich Wolf-Rayet colliding winds JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - Carbon-rich Wolf-Rayet stars are efficient carbon dust makers. Despite the strong evidence for dust formation in these objects provided by infrared thermal emission from dust, the routes to nucleation and condensation and the physical conditions required for dust production are still poorly understood. We discuss here the potential routes to carbon dust and the possible locations conducive to dust formation in the colliding winds of WC binaries. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88177 SP - 269 EP - 274 ER - TY - JOUR A1 - Guerrero, Martín A. T1 - Planetary nebulae and Their Central Stars in X-rays JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - Two types of X-ray sources are mostly found in planetary nebulae (PNe): point sources at their central stars and diffuse emission inside hot bubbles. Here we describe these two types of sources based on the most recent observations obtained in the framework of the Chandra Planetary Nebula Survey, ChanPlaNS, an X-ray survey targeting a volume-limited sample of PNe. Diffuse X-ray emission is found preferentially in young PNe with sharp, closed inner shells. Point sources of X-ray emission at the central stars reveal magnetically active binary companions and shock-in stellar winds. Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88160 SP - 263 EP - 266 ER - TY - JOUR A1 - Miszalski, B. A1 - Manick, R. A1 - McBride, V. T1 - Post-common-envelope Wolf-Rayet central stars of planetary nebulae JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015 N2 - Nearly 50 post-common-envelope (post-CE) close binary central stars of planetary nebulae (CSPNe) are now known. Most contain either main sequence or white dwarf (WD) companions that orbit the WD primary in around 0.1–1.0 days. Only PN G222.8–04.2 and NGC 5189 have post-CE CSPNe with a Wolf-Rayet star primary (denoted [WR]), the low-mass analogues of massive Wolf-Rayet stars. It is not well understood how H-deficient [WR] CSPNe form, even though they are relatively common, appearing in over 100 PNe. The discovery and characterisation of post-CE [WR] CSPNe is essential to determine whether proposed binary formation scenarios are feasible to explain this enigmatic class of stars. The existence of post-CE [WR] binaries alone suggests binary mergers are not necessarily a pathway to form [WR] stars. Here we give an overview of the initial results of a radial velocity monitoring programme of [WR] CSPNe to search for new binaries. We discuss the motivation for the survey and the associated strong selection effects. The mass functions determined for PN G222.8–04.2 and NGC 5189, together with literature photometric variability data of other [WR] CSPNe, suggest that of the post-CE [WR] CSPNe yet to be found, most will have WD or subdwarf O/B-type companions in wider orbits than typical post-CE CSPNe (several days or months c.f. less than a day). Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88156 SP - 259 EP - 262 ER -