Optical Observations of GRO J1655?40 in Quiescence. I. A Precise Mass for the Black Hole Primary

摘要: We report photometric and spectroscopic observations of the black hole binary GRO J1655-40 in complete quiescence. In contrast to 1995 photometry, light curves from 1996 are almost completely dominated by ellipsoidal modulations secondary star. Model fits curves, which take into account temperature profile accretion disk eclipse effects, yield an inclination i = 6950 ? 008 a mass ratio Q M1/M2 2.99 0.08. The precision our determinations allow us determine accuracy 4% (M1 7.02 0.22 M?). star's is M2 2.34 0.12 M?. position on Hertzsprung-Russell diagram consistent with that 2.3 M? star has evolved off main sequence halfway start giant branch. Using new spectra, we present improved value period (P 262157 000015), radial velocity semiamplitude (K 228.2 2.2 km s-1), function [f(M) 3.24 0.09 M?]. Based spectra source several MK spectral type standards, classify as F3 IV-F6 IV. Evolutionary models suggest average transfer rate for such system ${u{M}{"705F}}$ --> -->2=3.4?10 -->?9 yr-1 2.16 1017 g s-1, much larger than rates implied other six transient systems but still barely below critical required stability.