MULTITEMPERATURE BLACKBODY SPECTRA OF THIN ACCRETION DISKS WITH AND WITHOUT A ZERO-TORQUE INNER BOUNDARY CONDITION

摘要: The standard spectral model for analyzing the soft component of thermal emission from a thin accretion disk around black hole is multitemperature blackbody model. widely used implementation this model, which known as diskbb, assumes nonzero torque at inner edge disk. This assumption contrary to classic and current literature on thin-disk accretion, advocates use zero-torque boundary condition. Consequently, we have written code ezdiskbb, compare nonzero-torque diskbb by fitting Rossi X-Ray Timing Explorer spectra three well-known binaries: 4U 1543-47, XTE J1550-564, GRO J1655-40. chief difference find that gives value radius ≈2.2 times smaller than given diskbb. result has important implications, especially determination angular momentum mass rate.