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ezdiskbb: multiple blackbody disk model with zero-torque inner boundary

A multi-temperature blackbody model for a thin, steady-state, Newtonian accretion disk, assuming zero torque at the inner boundary for the disk at radius $R_{in}$. The temperature of the disk as a function of radius is assumed to be $T(r) = T_* r^{-3/4} (1-r^{-1/2})^{1/4}$, where $r = R/R_{in}$ and $T_* = f(3GM\dot{M}/8\pi R_{in}^3\sigma)^{1/4}$. The maximum temperature in the disk is given by $T_{max} = 0.488 T_*$.

This model is an alternative to diskbb, which assumes a non-zero torque at the inner edge and a temperature profile $T(r) = T_* r^{-3/4}$, and it should be used to fit spectra of disks when the zero-torque inner boundary condition is appropriate. For details see Zimmerman et al. (2005).

par1 maximum temperature in the disk (keV)
norm normalization = $(1/f^4) (R_{in}/D)^2 cos i$, where $R_{in}$ is the inner radius of the disk in km, $D$ is the distance to the source in units of 10 kpc, $i$ is the inclination, and $f$ is the color to effective temperature ratio.