Synopsis
The XSPEC TBgrain model: ISM grain absorption.
Syntax
xstbgrain The xstbgrain model is a multiplicative model component.
Description
The model is described at [1] .
Example
>>> create_model_component("xstbgrain", "mdl") >>> print(mdl)
Create a component of the xstbgrain 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.h2 frozen 0.2 0 1 mdl.rho frozen 1 0 5 g/cm^3 mdl.amin frozen 0.025 0 0.25 mum mdl.amax frozen 0.25 0 1 mum mdl.PL frozen 3.5 0 5
ATTRIBUTES
The attributes for this object are:
Attribute | Definition |
---|---|
nH | The equivalent hydrogen column (in units of 10^22 atoms/cm^2). |
h2 | The equivalent molecular hydrogen column (in units of 10^22 atoms/cm^2). |
rho | The grain density, in g/cm^3. |
amin | The minimum grain size, in micro-meters. |
amax | The maximum grain size, in micro-meters. |
PL | The power-law index of grain sizes. |
Notes
The `set_xsabund` function changes the relative abundances of the elements, in particular the "wilm" setting.
References
- [1] https://heasarc.gsfc.nasa.gov/xanadu/xspec/manual/XSmodelTbabs.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.