Parameters of V404 Cyg—A black-hole binary
摘要
We present the results of spectroscopic observations of the X-ray binary V404 Cyg obtained on the 6-m telescope of the Special Astrophysical Observatory in 2001–2002. We have used a statistical approach to interpret the radial-velocity curve of V404 Cyg. We derived the dependence of the mass of the X-ray emitting component m x on the mass of the optical component m v via an analysis of the radial-velocity curve based on profiles of the CaI 6439.075 Å absorption line synthesized in a Roche model. Using the orbital inclination estimated from the ellipticity of the optical component, i=54°–64°, and the component-mass ratio q=m x/m v=16.7 found from the rotational broadening of the spectral lines, we obtain m s =10.65±1.95M ⊙ for the mass of the black hole.