Last modified: December 2018

URL: http://cxc.harvard.edu/sherpa/ahelp/xszigm.html
AHELP for CIAO 4.11 Sherpa v1

xszigm

Context: models

Synopsis

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

Syntax

xszigm

The xszigm model is a multiplivative 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:

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 4.11 comes with support for version 12.10.0e of the XSPEC models. This can be checked with the following:

% python -c 'from sherpa.astro import xspec;
print(xspec.get_xsversion())'
12.10.0e

Bugs

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