On the Temperature Profile of Radiatively Efficient Geometrically Thin Disks in Black Hole Binaries with theASCAGIS

X-ray spectra of black hole binaries(BHBs) in the high/soft state werestudied comprehensively by using ASCA GIS data, and partially RXTE PCA data. Amathematical disk model was applied to several BHBs to see if the observedaccretion disk temperature profile was consistent with that expected from thestandard accretion disk model. This model is called p-free disk, and assumesthat the spectrum is composed of multi-temperature blackbody emission of whichthe local temperature T(r) at radius r is given by T(r) ~ r^-p with p being apositive free parameter. The standard disk roughly requires p~3/4, while asmall deviation is expected depending on the inner boundary conditions, generalrelativistic effects and disk vertical structures.Our sample objects includedLMC X-1, LMC X-3, XTE J2012+381, and GRO J1655-40. During the ASCAobservations, these BHBs showed characteristics of the standard high/softstate. Under the standard modeling of high-state black hole binaries, thesources show Tin=0.76-1.17keV, the disk fraction to the total 0.7-10keV flux of54-98%, and Nh=(0.7--12)E21/cm^2. The best-fit p-values were found in 0.6-0.8,and the standard value of p=3/4 was accepted for all the sources.The obtainedp-values are also compared with those expected for the standard accretion diskin the Schwarzschild metric, and they were consistent with those expected fromthe standard accretion disk.Comment: 25 pages, 20 figures, resubmitted to ApJ by taking referee's comments into accoun