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URN: urn:nbn:de:kobv:517-opus-18133
URL: http://opus.kobv.de/ubp/volltexte/2008/1813/


Oskinova, Lidia M. ; Hamann, Wolf-Rainer ; Feldmeier, Achim

X-raying clumped stellar winds

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Dokument 1.pdf (233 KB)


Kurzfassung in Englisch

X-ray spectroscopy is a sensitive probe of stellar winds. X-rays originate from optically thin shock-heated plasma deep inside the wind and propagate outwards throughout absorbing cool material. Recent analyses of the line ratios from He-like ions in the X-ray spectra of O-stars highlighted problems with this general paradigm: the measured line ratios of highest ions are consistent with the location of the hottest X-ray emitting plasma very close to the base of the wind, perhaps indicating the presence of a corona, while measurements from lower ions conform with the wind-embedded shock model. Generally, to correctly model the emerging Xray spectra, a detailed knowledge of the cool wind opacities based on stellar atmosphere models is prerequisite. A nearly grey stellar wind opacity for the X-rays is deduced from the analyses of high-resolution X-ray spectra. This indicates that the stellar winds are strongly clumped. Furthermore, the nearly symmetric shape of X-ray emission line profiles can be explained if the wind clumps are radially compressed. In massive binaries the orbital variations of X-ray emission allow to probe the opacity of the stellar wind; results support the picture of strong wind clumping. In high-mass X-ray binaries, the stochastic X-ray variability and the extend of the stellar-wind part photoionized by X-rays provide further strong evidence that stellar winds consist of dense clumps.

RVK - Regensburger Verbundklassifikation: US 1999.07
Collection 1: Universität Potsdam / Tagungen / Clumping in hot-star winds: International Workshop, Potsdam, Germany, 18. - 22. June 2007 / Talks and Discussions (organized by sections) / X-rays
Collection 2: Universität Potsdam / Tagungen / Clumping in hot-star winds: International Workshop, Potsdam, Germany, 18. - 22. June 2007 / Talks and Discussions (in alphabetical order)
Collection 3: Universität Potsdam / Tagungen / Clumping in hot-star winds: International Workshop, Potsdam, Germany, 18. - 22. June 2007
Institut: Institut für Physik und Astronomie
DDC-Sachgruppe: Astronomie
Dokumentart: c InProceedings (Aufsatz / Paper einer Konferenz etc.)
Sprache: Englisch
Erstellungsjahr: 2007
Publikationsdatum: 25.04.2008
Bemerkung:
The complete edition of the proceedings "Clumping in hot-star winds" is available:
urn:nbn:de:kobv:517-opus-13981
Lizenz: Diese Nutzungsbedingung gilt nicht, wenn in den Metadaten eine modifizierende Lizenz genannt ist. Keine Nutzungslizenz vergeben - es gilt das deutsche Urheberrecht


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