kerrd: optically thick accretion disk around a Kerr black hole

Optically thick extreme-Kerr disk model based on the same tranfer-function used in the laor Kerr disk-line model. Local emission is simply assumed to be the diluted blackbody. See Laor (1991) for an explanation of the transfer function. See Ebisawa et al. (2003) for examples of using this model.

par1 distance (kpc)
par2 spectral hardening factor, Tcol/Teff. Should be greater than 1.0, and considered to be 1.5-1.9 for accretion disks around a stellar-mass black hole. See, e.g., Shimura & Takahara (1995) 445, 780
par3 mass of the central object (solar unit)
par4 mass accretion rate ($10^{18}$ g/s)
par5 disk inclination angle (deg; 0 for face-on)
par6 inner radius (units of $GM/c^2$). 1.235 is the last stable orbit.
par7 outer radius (units of $GM/c^2$)
K normalization factor. should be fixed to 1.