Last modified: December 2025

URL: https://cxc.cfa.harvard.edu/sherpa/ahelp/xstbabs.html
AHELP for CIAO 4.18 Sherpa

xstbabs

Context: models

Synopsis

The XSPEC TBabs model: ISM grain absorption.

Syntax

xstbabs

The xstbabs model is a multiplicative model component.

Description

The model is described at [1] .


Example

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

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

mdl
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.nH       thawed            1            0        1e+06 10^22 atoms / cm^2

ATTRIBUTES

The attribute for this object is:

Attribute Definition
nH The equivalent hydrogen column (in units of 10^22 atoms/cm^2).

Notes

The `set_xsabund` function changes the relative abundances of the elements, in particular the "wilm" setting.

References

[1]

XSPEC version

CIAO 4.18 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.

See Also

models
xstbfeo, xstbgas, xstbgrain, xstbpcf, xstbrel, xstbvarabs, xsztbabs