Multi-temperature disk blackbody with power-law dependence of temperature on radius

NOTE: This model is now in the Xspec release and this page is superceded by the Xspec manual

A multiple blackbody disk model where local disk temperature T(r) is proportional to r^-p, where p is a free parameter. In the case of diskbb model (standard disk), p is 0.75, while p is expected to be smaller than 0.75 when radial advection is dominant. See discussion and examples in, e.g., Mineshige et al. 1994, ApJ, 426, 308, Hirano et al. 1995, ApJ, 446, 350, Watarai et al. 2000, PASJ, 52, 133, Kubota and Makishima 2004, ApJ, 601, 428, Kubota et al. 2005, ApJ, 631, 1062.

Update on 10/26/06 : the normalization was wrong in that it was 0.75/p times smaller than required. The correct normalization is obtained by multiplying 0.75/p to the normalization of the old version of the code. Since the disk radius is proportional to the square root of the normalization, and p can be as low as 0.5, the correct inner radius may be up to 1.11 time greater than the radius obtained from the old version of the code.

par1=temperature at inner disk radius (keV)
par2=exponent of the radial dependence of the disk temprature
K=((Rin/km)/(D/10kpc))^2 * cos(theta), where Rin is the inner disk radius, D the distance to the source, and theta the angle of the disk

To install this as a local model download the source, lmodel.dat description.

Keith Arnaud, Lab. for High Energy Astrophysics, NASA/Goddard Space Flight Center

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Last modified: Tuesday, 14-Feb-2023 16:42:06 EST