Variability of the Hα emission of Cygnus X-1 and its connection with the soft X-ray radiation
| Autor: | V. M. Lyuty, C. Brocksopp, A. E. Tarasov |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Physics
Soft x ray Astrophysics::High Energy Astrophysical Phenomena Conjunction (astronomy) Astrophysics (astro-ph) FOS: Physical sciences Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Photoionization Astrophysics Radiation Orbital period Spectral line Wind model Space and Planetary Science Astrophysics::Solar and Stellar Astrophysics Supergiant Astrophysics::Galaxy Astrophysics |
| Zdroj: | Astronomy & Astrophysics. 402:237-246 |
| ISSN: | 1432-0746 0004-6361 1996-2002 |
| DOI: | 10.1051/0004-6361:20030148 |
| Popis: | High-resolution Halpha monitoring of Cyg X-1, HD226868 was carried out during 1996-2002 and the resultant spectra analysed in conjunction with 1.5-12 keV X-ray monitoring. We demonstrate that the Halpha line-profiles have complex variability on different timescales, controlled in particular by the orbital period and the focused wind model of mass loss. We find that long-term variability of the mass loss by the supergiant and short-term variability due to clumpy structure of the stellar wind dominate during the low/hard X-ray state and that X-ray photoionization has a relatively small influence on the line-profile shape and EW variability. During the high/soft X-ray state and flaring the effect of photoionization the line-profile and EW of Halpha increases but is still unable to describe the loose anti-correlation between EW and the low energy X-ray emission. We propose that variability of the mass loss by the supergiant can change wind velocities in the Stromgren zone around the accretion disc of the secondary, leading to an increase in accretion rate through the disc. Comment: Accepted for publication in A&A |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|