Optical spectrum of HDE 226868 = Cygnus X-1. II. Spectrophotometry and mass estimates

Journal Article · Thu May 01 04:00:00 EDT 1986 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/164171· OSTI ID:5491989

Gies, D R; Bolton, C T

In part I of this series, Gies and Bolton (1982) have presented the results of radial velocity measures of 78 high-dispersion spectrograms of HDE 226868 = Cyg X-1. For the present study, 55 of the best plates considered by Gies and Bolton were selected to form 10 average spectra. An overall mean spectrum with S/N ratio = 300 was formed by coadding the 10 averaged spectra. There is no evidence for statistically significant variations of the spectral type about the mean value of 09.7 Iab, and all the absorption line strengths are normal for the spectral type. Evidence is presented that the He II lambda 4846 emission line is formed in the stellar wind above the substellar point on the visible star. Probable values regarding the mass for the visible star and its companion are 33 and 16 solar masses, respectively. Theoretical He II lambda 4686 emission line profiles are computed for the focused stellar wind model for the Cyg X-1 system considered by Friend and Castor (1982). 105 references.

• Research Organization: David Dunlap Observatory, Richmond Hill, Canada
• OSTI ID: 5491989
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 304; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640103* -- Astrophysics & Cosmology-- Quasi-Stellar
Radio
& X-Ray Sources-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION SPECTRA
BINARY STARS
COSMIC RAY SOURCES
COSMIC X-RAY SOURCES
MASS
SPECTRA
STARS
VISIBLE SPECTRA