Last modified: December 2023

AHELP for CIAO 4.16 Sherpa


Context: models


The XSPEC diskir model: Irradiated inner and outer disk.



The xsdiskir model is an additive model component.


The model is described at [1] .

Deprecated in Sherpa 4.10.0

The lcld parameter has been renamed lcovrld to match the XSPEC definition. The name lcld can still be used to access the parameter, but this name will be removed in a future release.


>>> create_model_component("xsdiskir", "mdl")
>>> print(mdl)

Create a component of the xsdiskir model and display its default parameters. The output is:

   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.kT_disk  thawed            1         0.01            5        keV
   mdl.Gamma    thawed          1.7        1.001           10           
   mdl.kT_e     thawed          100            1         1000        keV
   mdl.LcovrLd  thawed          0.1            0           10           
   mdl.fin      frozen          0.1            0            1           
   mdl.rirr     thawed          1.2       1.0001           10           
   mdl.fout     thawed       0.0001            0          0.1           
   mdl.logrout  thawed            5            3            7           
   mdl.norm     thawed            1            0        1e+24           


The attributes for this object are:

Attribute Definition
kT_disk The temperature of the innermost part of the unilluminated disk, in keV.
Gamma The asymptotic power-law photon index.
kT_e The electron temperature (high-energy rollover) in keV.
LcovrLd The ratio of the luminosity in the Compton tail to that of the unilluminated disk.
fin The fraction of luminosity in the Compton tail which is thermalized in the inner disk. Generally fix at 0.1 as appropriate for an albedo of 0.3 and solid angle of 0.3.
rirr The radius of the Compton illuminated disk in terms of the inner disk radius.
fout The fraction of bolometric flux which is thermalized in the outer disk.
logrout The log (base 10) of the outer disk radius in terms of the inner disk radius.
norm The model normalization: it is the same definition as used for the xsdiskbb model.


XSPEC version

CIAO 4.16 comes with support for version 12.13.1e of the XSPEC models. This can be checked with the following:

% python -c 'from sherpa.astro import xspec;


See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.