Last modified: December 2023

AHELP for CIAO 4.16 Sherpa


Context: models


The XSPEC laor2 model: accretion disk with broken-power law emissivity profile, black hole emission line.



The xslaor2 model is an additive model component.


The model is described at [1] .

Deprecated in Sherpa 4.10.0

The ring and routg parameters have been renamed to rin_g and rout_g respectively to match the XSPEC definition. The names ring and routg can still be used to access the parameters, but they will be removed in a future release.


>>> create_model_component("xslaor2", "mdl")
>>> print(mdl)

Create a component of the xslaor2 model and display its default parameters. The output is:

   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.lineE    thawed          6.4            0          100        keV
   mdl.Index    frozen            3          -10           10           
   mdl.Rin_G    frozen        1.235        1.235          400           
   mdl.Rout_G   frozen          400        1.235          400           
   mdl.Incl     frozen           30            0           90        deg
   mdl.Rbreak   frozen           20        1.235          400           
   mdl.Index1   frozen            3          -10           10           
   mdl.norm     thawed            1            0        1e+24           


The attributes for this object are:

Attribute Definition
lineE The rest-frame line energy, in keV.
Index The power law dependence of emissivity (scales as R^-Index).
Rin_G The inner radius, in units of GM/c^2.
Rout_G The outer radius, in units of GM/c^2.
Incl The disk inclination angle, in degrees. A face-on disk has Incl=0.
Rbreak The radius at which the emissivity power-law index changes.
Index1 The emissivity power-law index for r>Rbreak.
norm The flux in the line, in units of photon/cm^2/s.


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.

See Also

xskdblur2, xslaor