xsbvnpshock

Context: models

Synopsis

The XSPEC bvnpshock model: shocked plasma, plane parallel, separate ion, electron temperatures.

Syntax

xsbvnpshock

The xsbvnpshock model is an additive model component.

Description

The model is described at [1] . The set_xsxset and get_xsxset functions are used to set and query the XSPEC XSET parameters, in particular the keyword "NEIVERS".

Example

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

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

mdl
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.kT_a     thawed            1       0.0808         79.9        keV
   mdl.kT_b     thawed          0.5         0.01         79.9        keV
   mdl.H        frozen            1            0            1           
   mdl.He       frozen            1            0        10000           
   mdl.C        frozen            1            0        10000           
   mdl.N        frozen            1            0        10000           
   mdl.O        frozen            1            0        10000           
   mdl.Ne       frozen            1            0        10000           
   mdl.Mg       frozen            1            0        10000           
   mdl.Si       frozen            1            0        10000           
   mdl.S        frozen            1            0        10000           
   mdl.Ar       frozen            1            0        10000           
   mdl.Ca       frozen            1            0        10000           
   mdl.Fe       frozen            1            0        10000           
   mdl.Ni       frozen            1            0        10000           
   mdl.Tau_l    frozen            0            0        5e+13     s/cm^3
   mdl.Tau_u    thawed        1e+11        1e+08        5e+13     s/cm^3
   mdl.Redshift frozen            0       -0.999           10           
   mdl.Velocity frozen            0            0        10000       km/s
   mdl.norm     thawed            1            0        1e+24

ATTRIBUTES

The attributes for this object are:

Attribute	Definition
kT_a	The mean shock temperature, in keV.
kT_b	The electron temperature immediately behind the shock front, in keV. See [1] for a discussion of the behavior of kT_a and kT_b.
H	H abundance (set to 0 for no free-free continuum, otherwise 1).
He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Fe, Ni	The abundance relative to Solar.
Tau_l	The lower limit on the ionization timescale in s/cm^3.
Tau_u	The upper limit on the ionization timescale in s/cm^3.
redshift	The redshift of the source.
Velocity	The gaussian sigma of the velocity broadening, in km/s.
norm	The normalization of the model: see [1] for an explanation of the units.

References

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

Changes in CIAO

Added in CIAO 4.17

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.