Last modified: December 2018

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

xsvpshock

Context: models

Synopsis

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

Syntax

xsvpshock

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

Create a component of the xsvpshock 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            1           
   mdl.He       frozen            1            0         1000           
   mdl.C        frozen            1            0         1000           
   mdl.N        frozen            1            0         1000           
   mdl.O        frozen            1            0         1000           
   mdl.Ne       frozen            1            0         1000           
   mdl.Mg       frozen            1            0         1000           
   mdl.Si       frozen            1            0         1000           
   mdl.S        frozen            1            0         1000           
   mdl.Ar       frozen            1            0         1000           
   mdl.Ca       frozen            1            0         1000           
   mdl.Fe       frozen            1            0         1000           
   mdl.Ni       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, C, N, O, Ne, Mg, Si, S, Ar, Ca, Fe, Ni

The abundance of the element in solar units.

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, xsvvpshock