Last modified: December 2020

URL: https://cxc.cfa.harvard.edu/sherpa/ahelp/xszigm.html
AHELP for CIAO 4.13 Sherpa v1

xszigm

Context: models

Synopsis

The XSPEC zigm model: UV/Optical attenuation by the intergalactic medium.

Syntax

xszigm

The xszigm model is a multiplicative model component.

Description

The model is described at [1] .


Example

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

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

mdl
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.redshift frozen            0 -3.40282e+38  3.40282e+38           
   mdl.model    frozen            0 -3.40282e+38  3.40282e+38           
   mdl.lyman_limit frozen            1 -3.40282e+38  3.40282e+38           

ATTRIBUTES

The attributes for this object are:

Attribute Definition
redshift The redshift of the absorber. This parameter can not be thawed.
model The model to use: 0 is Madau, 1 is Meiksin. This parameter can not be thawed.
lyman_limit Should photoelectric absorption be included (1), or not (0). This parameter can not be thawed.

References

XSPEC version

CIAO 4.13 comes with support for version 12.10.1s of the XSPEC models. This can be checked with the following:

% python -c 'from sherpa.astro import xspec;
print(xspec.get_xsversion())'
12.10.1s

Bugs

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