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:
The power law photon index for energies less than BreakE1.
The first break energy, in keV.
The power law photon index for energies greater than BreakE1 but less than BreakE2.
The second break energy, in keV.
The power law photon index for energies greater than BreakE2.
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 4.12 comes with support for version 12.10.1n of the XSPEC models. This can be checked with the following:
% python -c 'from sherpa.astro import xspec; print(xspec.get_xsversion())' 12.10.1n
See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.