Other
Scientific paper
Apr 2007
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007iaus..238..389k&link_type=abstract
Black Holes from Stars to Galaxies -- Across the Range of Masses. Edited by V. Karas and G. Matt. Proceedings of IAU Symposium #
Other
Scientific paper
Selected results of multi-year optical photometric and high-resolution spectral observations including obtained in the frame of coordinated CIS countries campaign "Optical Monitoring of Unique Astrophysical Objects" are briefly reviewed. Comparison with ASM/RXTE X-ray data is used. Besides of orbital variations different kinds of flares, dips and so-called precession period 147/294 days were revealed. The observational evidences of instability of matter flowing from one component to another have been appeared. Cross-correlation analysis yielded the lags between the optical and X-ray (2-10 keV) long time variations with the delaying of the last ones on 7d in 1996 and 12d in 1997-1998. The very same lags were revealed between the optical and X-ray flares in these years. So the characteristic time of the matter transfer through the accretion disk was about 7 days in Summer and Autumn 1996 and about 12 days in 1997-1998 and alpha-model of accretion disc does not work. Optical spectral line profile variations were found during X-ray flare. The comparison of observed and non-LTE model profiles for HI, HeI and MgII is given taking into account tidal distortion of Cyg X-1 optical component and its illumination by X-ray emission of secondary one. We set limits on the optical component main characteristics T[eff] = 30400±500K, log g = 3.31±0.07 and overabundance of He and Mg: [He/H] = 0.43±0.06 dex, [Mg/H] = 0.75±0.15 dex by using spectra of 2003-2004. The Doppler images were reconstructed by an improved Doppler tomography method on the base of 9 HeIIλ4686Å profiles of 2003 ("soft" X-ray state) and 6 profiles of 2004 ("hard" X-ray state). It allowed putting a limitation on the black hole to supergiant mass ratio 1/4 ≤ M[X]/M[O] ≤ 1/3. The photometric and spectral variations point to the supergiant parameters changes on the time scale of tens of years. Line profile non-LTE simulations lead to the conclusion that the star radius has grown about 1-4% from 1997 to 2003-2004 and the temperature decreased by 1300-2400K.
No associations
LandOfFree
The results of X-ray binary Cyg X-1 investigations based on the optical photometry and high-resolution spectroscopy does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The results of X-ray binary Cyg X-1 investigations based on the optical photometry and high-resolution spectroscopy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The results of X-ray binary Cyg X-1 investigations based on the optical photometry and high-resolution spectroscopy will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1082901