Last modified: December 2018

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

xsgrbcomp

Context: models

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:

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.

New in CIAO 4.11

The xsgrbcomp model (added in XSPEC 12.10.0) is new in CIAO 4.11

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.

See Also

models
xsgrbm