Synopsis
The XSPEC vmshift convolution model: velocity shift a multiplicative model.
Syntax
xsvmshift The xsvmshift model is a convolution model component.
Description
The model is described at [1] .
Example
>>> create_model_component("xsvmshift", "mdl")
>>> print(mdl)Create a component of the xsvmshift model and display its default parameters. The output is:
mdl Param Type Value Min Max Units ----- ---- ----- --- --- ----- mdl.Velocity frozen 0 -10000 10000 km/s
ATTRIBUTES
The attribute for this object is:
| Attribute | Definition |
|---|---|
| Velocity | The velocity, in km/s. |
Notes
Unlike XSPEC, the convolution model is applied directly to the model, or models, rather than using the multiplication symbol.
References
- [1] https://heasarc.gsfc.nasa.gov/xanadu/xspec/manual/XSmodelVmshift.html
Changes in CIAO
Changed in CIAO 4.14
The Velocity parameter was incorrectly labelled as Redshift: both names can be used to access this parameter.
Added in CIAO 4.13
XSPEC version
CIAO 4.17 comes with support for version 12.14.0k of the XSPEC models. This can be checked with the following:
% python -c 'from sherpa.astro import xspec; print(xspec.get_xsversion())' 12.14.0k
Bugs
See the bugs pages on the Sherpa website for an up-to-date listing of known bugs.