Last modified: December 2018

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

xsvvnpshock

Context: models

Synopsis

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

Syntax

xsvvnpshock

The xsvvnpshock 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("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:

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

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
xsnpshock, xsvnpshock