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

xsvvnpshock
The xsvvnpshock model is an additive model component.

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".

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

Create a component of the xsvvnpshock 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 1000 mdl.He frozen 1 0 1000 mdl.Li frozen 1 0 1000 mdl.Be frozen 1 0 1000 mdl.B frozen 1 0 1000 mdl.C frozen 1 0 1000 mdl.N frozen 1 0 1000 mdl.O frozen 1 0 1000 mdl.F frozen 1 0 1000 mdl.Ne frozen 1 0 1000 mdl.Na frozen 1 0 1000 mdl.Mg frozen 1 0 1000 mdl.Al frozen 1 0 1000 mdl.Si frozen 1 0 1000 mdl.P frozen 1 0 1000 mdl.S frozen 1 0 1000 mdl.Cl frozen 1 0 1000 mdl.Ar frozen 1 0 1000 mdl.K frozen 1 0 1000 mdl.Ca frozen 1 0 1000 mdl.Sc frozen 1 0 1000 mdl.Ti frozen 1 0 1000 mdl.V frozen 1 0 1000 mdl.Cr frozen 1 0 1000 mdl.Mn frozen 1 0 1000 mdl.Fe frozen 1 0 1000 mdl.Co frozen 1 0 1000 mdl.Ni frozen 1 0 1000 mdl.Cu frozen 1 0 1000 mdl.Zn frozen 1 0 1000 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.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
The H abundance: it should be set to 0 to switch on and 1 to switch off the free-free continuum.
He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn
The abundance of the element, with respect 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.
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

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