sinds 05 februari 2011 :
Weergave(s): 22 (0 ULiège)
Download(s): 0 (0 ULiège)
print        
Wolf-Rainer Hamann, Ludwig Schulz & Helge Todt

Modeling Stellar Wind Spectra from Rapidly Rotating Stars

(Volume 93 - Année 2024 — No 3 - 41st Liège International Astrophysical Colloquium)
Article
Open Access

Documenten bij dit artikel

Version PDF originale

Abstract

In post-interaction massive binaries (PIMBs) one often finds rapidly rotating objects, e.g., after one component has accreted mass and angular momentum, or after two components merged. Being hot and luminous, such objects drive stellar winds. Models for stellar atmospheres and winds usually adopt spherical symmetry. However, rapid rotation would break this symmetry.
We have developed a version of the Potsdam Wolf–Rayet (PoWR) model atmosphere code which allows to combine two different atmosphere models, e.g., one for the rapid wind over the polar regions, and a second one for the slower wind over the gravity-darkened equatorial zone.
For two examples we will demonstrate that such 1.5-D spectral simulations can explain observed wind-line profiles which otherwise cannot be reproduced.

Keywords : stars: rotation, stars: winds, stars: model atmospheres

This work is distributed under the Creative Commons CC BY 4.0 Licence.

Paper presented at the 41st Liège International Astrophysical Colloquium on “The eventful life of massive star multiples,” University of Liège (Belgium), 15–19 July 2024.

Bibliographie

Bjorkman, J. E. and Cassinelli, J. P. (1993) Equatorial disk formation around rotating stars due to ram pressure confinement by the stellar wind. ApJ, 409, 429–449. https://doi.org/10.1086/172676.

Bjorkman, J. E., Ignace, R., Tripp, T. M., and Cassinelli, J. P. (1994) Evidence for a disk in the wind of HD 93521: UV line profiles from an axisymmetric model. ApJ, 435, 416–434. https://doi.org/10.1086/174825.

Britavskiy, N., Simón-Díaz, S., Holgado, G., Burssens, S., Maíz Apellániz, J., Eldridge, J. J., Nazé, Y., Pantaleoni González, M., and Herrero, A. (2023) The IACOB project. VIII. Searching for empirical signatures of binarity in fast-rotating O-type stars. A&A, 672, A22. https://doi.org/10.1051/0004-6361/202245145.

Hamann, W.-R. and Gräfener, G. (2003) A temperature correction method for expanding atmospheres. A&A, 410(3), 993–1000. https://doi.org/10.1051/0004-6361:20031308.

Ramachandran, V., Hamann, W.-R., Oskinova, L. M., Gallagher, J. S., Hainich, R., Shenar, T., Sander, A. A. C., Todt, H., and Fulmer, L. (2019) Testing massive star evolution, star formation history, and feedback at low metallicity: Spectroscopic analysis of OB stars in the SMC Wing. A&A, 625, A104. https://doi.org/10.1051/0004-6361/201935365.

Shenar, T., Hamann, W.-R., and Todt, H. (2014) The impact of rotation on the line profiles of Wolf–Rayet stars. A&A, 562, A118. https://doi.org/10.1051/0004-6361/201322496.

von Zeipel, H. (1924) The radiative equilibrium of a rotating system of gaseous masses. MNRAS, 84, 665–683. https://doi.org/10.1093/mnras/84.9.665.

Walker, G. A. H., Kuschnig, R., Matthews, J. M., Reegen, P., Kallinger, T., Kambe, E., Saio, H., Harmanec, P., Guenther, D. B., Moffat, A. F. J., Rucinski, S. M., Sasselov, D., Weiss, W. W., Bohlender, D. A., Božić, H., Hashimoto, O., Koubský, P., Mann, R., Ruždjak, D., Škoda, P., Šlechta, M., Sudar, D., Wolf, M., and Yang, S. (2005) Pulsations of the Oe star ζ Ophiuchi from MOST satellite photometry and ground-based spectroscopy. ApJL, 623(2), L145–L148. https://doi.org/10.1086/430254.

Om dit artikel te citeren:

Wolf-Rainer Hamann, Ludwig Schulz & Helge Todt, «Modeling Stellar Wind Spectra from Rapidly Rotating Stars», Bulletin de la Société Royale des Sciences de Liège [En ligne], Volume 93 - Année 2024, No 3 - 41st Liège International Astrophysical Colloquium, 244-249 URL : https://popups.uliege.be/0037-9565/index.php?id=12330.

Over : Wolf-Rainer Hamann

Universität Potsdam, Germany
email : wrh@astro.physik.uni-potsdam.de

Over : Ludwig Schulz

Universität Potsdam, Germany

Over : Helge Todt

Universität Potsdam, Germany