xsvmshift

Context: models

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 4.16 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.