diskpn: accretion disk, black hole, black body

Blackbody spectrum of an accretion disk. This is an extension of the diskbb model, including corrections for temperature distribution near the black hole. The temperature distribution was calculated in Paczynski-Wiita pseudo-Newtonian potential. An accretion rate can be computed from the maximum temperature found.  For details see Gierlinski et al., 1999, MNRAS, 309, 496. Please note that the inner disk radius (par2) can be a free parameter only close to par2 = 6; otherwise par2 is strongly correlated with K.

par1	maximum temperature in the disk (keV)
par2	inner disk radius in Rg = GM/c2 units,
norm	normalization, where M = central mass (solar masses), D distance to the source (kpc), i inclination of the disk, and b color/effective temperature ratio.