Synopsis
The XSPEC vphabs model: photoelectric absorption.
Syntax
xsvphabs The xsvphabs model is a multiplicative model component.
Description
The model is described at [1] .
Example
>>> create_model_component("xsvphabs", "mdl")
>>> print(mdl)Create a component of the xsvphabs 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 mdl.He frozen 1 0 1000 mdl.C frozen 1 0 1000 mdl.N frozen 1 0 1000 mdl.O frozen 1 0 1000 mdl.Ne frozen 1 0 1000 mdl.Na frozen 1 0 1000 mdl.Mg frozen 1 0 1000 mdl.Al frozen 1 0 1000 mdl.Si frozen 1 0 1000 mdl.S frozen 1 0 1000 mdl.Cl frozen 1 0 1000 mdl.Ar frozen 1 0 1000 mdl.Ca frozen 1 0 1000 mdl.Cr frozen 1 0 1000 mdl.Fe frozen 1 0 1000 mdl.Co frozen 1 0 1000 mdl.Ni frozen 1 0 1000
ATTRIBUTES
The attributes for this object are:
| Attribute | Definition |
|---|---|
| nH | The equivalent hydrogen column (in units of 10^22 atoms/cm^2). |
| He, C, N, O, Ne, Na, Mg, Al, Si, S, Cl, Ar, Ca, Cr, Fe, Co, Ni | The abundance of the element in solar units. |
Notes
The `set_xsxsect` function changes the cross sections used by this model. The `set_xsabund` function changes the relative abundances of the elements.
References
- [1] https://heasarc.gsfc.nasa.gov/xanadu/xspec/manual/XSmodelPhabs.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.