The XSPEC bkn2pow model: broken power law with two breaks.
xsbkn2pow The xsbkn2pow model is an additive model component.
The model is described at  .
>>> create_model_component("xsbkn2pow", "mdl") >>> print(mdl)
Create a component of the xsbkn2pow model and display its default parameters. The output is:
mdl Param Type Value Min Max Units ----- ---- ----- --- --- ----- mdl.PhoIndx1 thawed 1 -2 9 mdl.BreakE1 thawed 5 0.01 1e+06 keV mdl.PhoIndx2 thawed 2 -2 9 mdl.BreakE2 thawed 10 0.01 1e+06 keV mdl.PhoIndx3 thawed 3 -2 9 mdl.norm thawed 1 0 1e+24
The attributes for this object are:
|PhoIndx1||The power law photon index for energies less than BreakE1.|
|BreakE1||The first break energy, in keV.|
|PhoIndx2||The power law photon index for energies greater than BreakE1 but less than BreakE2.|
|BreakE2||The second break energy, in keV.|
|PhoIndx3||The power law photon index for energies greater than BreakE2.|
|norm||The normalization of the model. See  for details, as its meaning depends on whether the "POW_EMIN" or "POW_EMAX" keywords have been set with set_xsxset .|
-  https://heasarc.gsfc.nasa.gov/xanadu/xspec/manual/XSmodelBkn2pow.html
CIAO 4.13 comes with support for version 12.10.1s of the XSPEC models. This can be checked with the following:
% python -c 'from sherpa.astro import xspec; print(xspec.get_xsversion())' 12.10.1s
See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.