xspowerlaw

Context: models

Synopsis

The XSPEC powerlaw model: power law photon spectrum.

Syntax

xspowerlaw

The xspowerlaw model is an additive model component.

Description

The model is described at [1] .

Example

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

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

mdl
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.PhoIndex thawed            1           -3           10           
   mdl.norm     thawed            1            0        1e+24

ATTRIBUTES

The attributes for this object are:

Attribute	Definition
PhoIndex	The power law photon index.
norm	The normalization of the model. See [1] for details, as its meaning depends on whether the "POW_EMIN" or "POW_EMAX" keywords have been set with set_xsxset .

References

[1] https://heasarc.gsfc.nasa.gov/xanadu/xspec/manual/XSmodelPowerlaw.html

XSPEC version

CIAO 4.17 comes with support for version 12.14.0k of the XSPEC models. This can be checked with the following:

% python -c 'from sherpa.astro import xspec;
print(xspec.get_xsversion())'
12.14.0k

Bugs

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