Last modified: December 2021

URL: https://cxc.cfa.harvard.edu/sherpa/ahelp/xsxscat.html
AHELP for CIAO 4.14 Sherpa

xsxscat

Context: models

Synopsis

The XSPEC xscat model: dust scattering.

Syntax

xsxscat

The xsxscat model is a multiplicative model component.

Description

The model is described at [1] .


Example

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

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

mdl
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.NH       thawed            1            0         1000      10^22
   mdl.Xpos     thawed          0.5            0        0.999           
   mdl.Rext     frozen           10            0          240     arcsec
   mdl.DustModel frozen            1 -3.40282e+38  3.40282e+38           

ATTRIBUTES

The attributes for this object are:

Attribute Definition
NH Interstellar hydrogen column density (in units of 10^22 atoms/cm^2).
Xpos The relative position of the dust along the line of sight. A value of 0 means the dust is at the observer, and of 0.95 means that the dust is 5% from the source.
Rext The radius of the circular extraction region, in arcsec.
DustModel The dust model used: see [1] for more information.

References

XSPEC version

CIAO 4.14 comes with support for version 12.12.0 of the XSPEC models. This can be checked with the following:

% python -c 'from sherpa.astro import xspec;
print(xspec.get_xsversion())'
12.12.0

Bugs

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