Slim disk: Viscosity prescriptions and observational implications

We examine how different viscosity prescriptions and magnitudes affect the structure of the slim disk. Unlike the case with a standard disk, radiation from the slim disk is influenced by the viscosity parameter, alpha, in suc h a way that the estimated maximum effective temperature of the disk slight ly increases as alpha increases. This is because the larger is alpha, the l arger does the accretion velocity become and, hence, the more enhanced does the advective energy transport become, which means less efficient radiativ e cooling and thus higher temperatures. Furthermore, we checked different v iscosity prescriptions with the form of the viscous stress tensor of t(r ph i) = -alpha beta (mu)p(total), where beta is the ratio of the gas pressure to the total pressure, and mu is a parameter (0 less than or equal to mu le ss than or equal to 1). In contrast with the case with It = 0, which shows significant decrease in the inner-edge radius and the flattering of the eff ective temperature profile at high luminosities, for large mu, say mu simil ar to 0.5, neither of the inner-edge of the disk nor temperature profiles d oes not appreciably change even at the Eddington luminosity. We can rule ou t a case with large mu (similar to 0.5), since it would not be able to prod uce a drop in the inner-edge radius of an increase in the luminosity, as wa s observed in an ultraluminous X-ray source, IC 342, source 1.