Last modified: December 2023

URL: https://cxc.cfa.harvard.edu/sherpa/ahelp/xsbvapec.html
AHELP for CIAO 4.16 Sherpa

xsbvapec

Context: models

Synopsis

The XSPEC bvapec model: velocity broadened APEC thermal plasma model.

Syntax

xsbvapec

The xsbvapec model is an additive model component.

Description

The model is described at [1] , with xsbapec describing how it is implemented in Sherpa.


Example

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

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

mdl
   Param        Type          Value          Min          Max      Units
   -----        ----          -----          ---          ---      -----
   mdl.kT       thawed          6.5       0.0808       68.447        keV
   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.Al       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.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 The temperature of the plasma, in keV.
He, C, N, O, Ne, Mg, Al, Si, S, Ar, Ca, Fe, Ni The abundance of the element in solar units.
Redshift The redshift of the plasma.
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

Changes in CIAO

Changed in CIAO 4.16

The maximum for the Velocity parameter has been changed from 10^6 to 10^4 km/s.

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

Bugs

See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.

See Also

models
xsapec, xsbapec, xsbvvapec, xsvapec, xsvvapec