Last modified: December 2018

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

xsvvpshock

Context: models

Synopsis

The XSPEC vvpshock model: plane-parallel shocked plasma, constant temperature.

Syntax

xsvvpshock

The xsvvpshock 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("xsvvpshock", "mdl")
>>> print(mdl)

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

mdl
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.kT       thawed            1       0.0808         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

The temperature of the plasma, in keV.

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 plasma.

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
xspshock, xsvpshock