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
- [1] https://heasarc.gsfc.nasa.gov/xanadu/xspec/manual/XSmodelZigm.html
XSPEC version
CIAO 4.17 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.