Synopsis
The XSPEC grbcomp model: Comptonization for GRB prompt emission.
Syntax
xsgrbcomp The xsgrbcomp model is an additive model component.
Description
The model is described at [1] .
Example
>>> create_model_component("xsgrbcomp", "mdl")
>>> print(mdl)Create a component of the xsgrbcomp model and display its default parameters. The output is:
mdl Param Type Value Min Max Units ----- ---- ----- --- --- ----- mdl.kTs thawed 1 0 20 keV mdl.gamma thawed 3 0 10 mdl.kTe thawed 100 0.2 2000 keV mdl.tau thawed 5 0 200 mdl.beta thawed 0.2 0 1 mdl.fbflag frozen 0 0 1 mdl.log_A frozen 5 -8 8 mdl.z frozen 0 0 10 mdl.a_boost frozen 5 0 30 mdl.norm thawed 1 0 1e+24
ATTRIBUTES
The attributes for this object are:
| Attribute | Definition |
|---|---|
| kTs | Temperature of the seed blackbody spectrum in keV. |
| gamma | If set to 3 the seed soft spectrum is a blackbody, otherwise it approximates a modified blackbody. |
| kTe | Electron temperature of the subrelativistic outflow in keV. |
| tau | Radial optical depth of the subrelativistic outflow. |
| beta | Bulk outflow velocity of the thermal electrons. |
| fbflag | If set to 0 then only the first-order bulk Comptonization term is considered, otherwise if set to 1 then the second-order term is computed (see [1] for more details). |
| log_A | The geometrical covering factor which determines the relative weights of the seed and comptonized spectra to the total flux. |
| z | Redshift. |
| a_boost | The energy index of the Green's function with which the formerly comptonization spectrum is convolved. |
| norm | The normalization of the model: see [1] for an explanation of the units. |
References
- [1] https://heasarc.gsfc.nasa.gov/xanadu/xspec/manual/XSmodelGrbcomp.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.