Narayan, Ramesh2019-09-221996Narayan, Ramesh. 1996. “Advection-Dominated Models of Luminous Accreting Black Holes.” The Astrophysical Journal 462 (May): 136. https://doi.org/10.1086/177136.0004-637X1538-4357http://nrs.harvard.edu/urn-3:HUL.InstRepos:41384902It has been found that a class of optically thin two-temperature advection-dominated accretion solutions explains many observations of low-luminosity accreting black holes. Here it is shown that these models give a satisfactory description also of higher luminosity systems, provided the viscosity parameter a is large. The models reproduce the spectra of black hole X-ray binaries in the low state and explain the transition from the low state to the high state at a critical mass accretion rate. The models also show that the X-ray/gamma-ray spectra of X-ray binaries and active galactic nuclei should be similar, as confirmed by observations.en-USJournal Article2019-09-2210.1086/177136