Last modified: December 2023

URL: https://cxc.cfa.harvard.edu/sherpa/ahelp/xsbexrav.html
AHELP for CIAO 4.16 Sherpa

xsbexrav

Context: models

Synopsis

The XSPEC bexrav model: reflected e-folded broken power law, neutral medium.

Syntax

xsbexrav

The xsbexrav model is an additive model component.

Description

The model is described at [1] .


Example

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

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

mdl
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.Gamma1   thawed            2          -10           10           
   mdl.breakE   thawed           10          0.1         1000        keV
   mdl.Gamma2   thawed            2          -10           10           
   mdl.foldE    thawed          100            1        1e+06        keV
   mdl.rel_refl thawed            0            0           10           
   mdl.cosIncl  frozen         0.45         0.05         0.95           
   mdl.abund    frozen            1            0        1e+06           
   mdl.Fe_abund frozen            1            0        1e+06           
   mdl.redshift frozen            0       -0.999           10           
   mdl.norm     thawed            1            0        1e+24           

ATTRIBUTES

The attributes for this object are:

Attribute Definition
Gamma1 The power-law index of the first power-law component.
breakE The break energy, in keV.
Gamma2 The power-law index of the second power-law component.
foldE The e-folding energy (Ec) in keV. If zero there is no cut off.
rel_refl The reflection scaling parameter (a value of 1 for an isotropic source above the disk).
cosIncl The cosine of the inclination angle.
abund The abundance of the elements heavier than He relative to their solar abundance, as set by the set_xsabund function.
Fe_abund The iron abundance relative to the solar abundance, as set by the set_xsabund function.
redshift The redshift of the source.
norm The normalization of the model: see [1] for an explanation of the units.

Notes

The precision of the numerical integration can be changed by using the set_xsxset function to set the value of the BEXRAV_PRECISION keyword, which defines the fractional precision. The default is 0.01 (1%).

References

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;
print(xspec.get_xsversion())'
12.13.1e

Bugs

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

See Also

models
xsbexriv, xsreflect