    The XSPEC grbjet model: Two-phase Comptonization model of soft thermal seed photons for GRB prompt emission

xsgrbjet
The xsgrbjet model is an additive model component.

The model is described at [1] .

>>> create_model_component("xsgrbjet", "mdl")
>>> print(mdl)

Create a component of the xsgrbjet model and display its default parameters. The output is:

mdl Param Type Value Min Max Units ----- ---- ----- --- --- ----- mdl.thobs frozen 5 0 30 mdl.thjet frozen 10 2 20 mdl.gamma thawed 200 1 500 mdl.r12 frozen 1 0.1 100 mdl.p1 thawed 0 -2 1 mdl.p2 thawed 1.5 1.1 10 mdl.E0 thawed 1 0.1 1000 keV mdl.delta frozen 0.2 0.01 1.5 mdl.index_pl frozen 0.8 0 1.5 mdl.ecut frozen 20 0.1 1000 keV mdl.ktbb frozen 1 0.1 1000 keV mdl.model frozen 1 -3.40282e+38 3.40282e+38 mdl.redshift frozen 2 0.001 10 mdl.norm thawed 1 0 1e+24

ATTRIBUTES

The attributes for this object are:

Attribute
Definition
thobs
The observing viewing angle in degrees.
thjet
The jet half-opening angle in degrees.
gamma
The jet gamma Lorentz factor.
r12
The jet radius in 10^12 cm.
p1
The low-energy index of the coming frame broken powerlaw spectrum.
p2
The high-energy index of the coming frame broken powerlaw spectrum.
E0
The break energy in keV.
delta
The smoothness of the transition between the two powerlaws.
index_pl
The energy index of the comoving-frame cutoff powerlaw spectrum.
ecut
The cut-off energy in keV.
ktbb
The comoving frame blackbody temperature in keV.
model
The comoving frame emissivity law: 1 is broken powerlaw, 2 is cutoff powerlaw, and 3 is blackbody.
redshift
The source redshift.
norm
The normalization of the model: see [1] for an explanation of the units.

References

[1] https://heasarc.gsfc.nasa.gov/xanadu/xspec/manual/XSmodelGrbjet.html

XSPEC version

CIAO 4.16 comes with support for version 12.13.1e of the XSPEC models. This can be checked with the following:

% python -c 'from sherpa.astro import xspec; print(xspec.get_xsversion())'12.13.1e

See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.

December 2023