Last modified: December 2019

AHELP for CIAO 4.12 Sherpa v1


Context: models


The XSpec convolution models *Experimental*.


The sherpa_contrib.xspec.xsconvolve module provides an *experimental* interface to the X-Spec convolution models. Please contact the CXC HelpDesk if you have problems with these models.

Convolution components apply a convolution operator to an input model flux calculated from a source (additive) model, as modified by other components (multiplicative factors or other convolution operators). They differ from multiplicative components, which only apply a bin-wise multiplicative factor, by allowing transformations of the flux across energy bins.

Commands to create convolution models

Name Description
load_xscflux calculate flux
load_xslumin calculate luminosity
load_xscpflux calculate photon flux
load_xsgsmooth gaussian smoothing
load_xsireflect reflection from ionized material
load_xskdblur convolve with the laor model shape
load_xskdblur2 convolve with the laor2 model shape
load_xskerrconv accretion disk line shape with BH spin as free parameter
load_xskyconv convolution using a relativistic line from axisymmetric accretion disk
load_xslsmooth lorentzian smoothing
load_xspartcov partial covering
load_xsrdblur convolve with the diskline model shape
load_xsreflect reflection from neutral material
load_xsrfxconv reflection from an ionized disk
load_xsrgsxsrc convolve an RGS spectrum for extended emission
load_xssimpl comptonization of a seed spectrum
load_xsvashift Velocity shift an additive model
load_xsvmshift Velocity shift a multiplicative model
load_xsxilconv reflection from an ionized disk
load_xszashift Redshift an additive model
load_xszmshift Redshift a multiplicative model

Loading the X-Spec convolution models

To use these model, the xsconvolve module from the CIAO contributed package must be installed. The relevant load routine can then be loaded with a command like

sherpa> from sherpa_contrib.xspec.xsconvolve import load_xscflux

or all models loaded by saying

sherpa> from sherpa_contrib.xspec.xsconvolve import *

The load command can then be used to create a component in the same manner as load_conv, namely

sherpa> load_zashift("zas")
sherpa> set_source( * zas( +
sherpa> zas.redshift = 0.23

which applies a local absorption model to the redshifted power law and gaussian componente.


XSpec version

This information is taken from the XSpec User's Guide. Version 12.10.1n of the XSpec models is supplied with CIAO 4.12.

Changes in the scripts 4.12.1 (December 2019) release

The kyconv model from XSPEC 12.10.1 has been added (note that the relconv set of models are not supported since they were removed in XSPEC 12.10.1m and CIAO includes XSPEC 12.10.1n).

Changes in the scripts 4.11.1 (December 2018) release

The supported models have expanded to include models added in XSPEC 12.10.0.

Changes in the scripts 4.9.2 (April 2017) release

The XSPEC convolution models now work again (an update in CIAO 4.8 had broken them).

Changes in the scripts 4.6.6 (September 2014) release

The sherpa_contrib.xspec.xsconvolve module is new in this release.

About Contributed Software

This script is not an official part of the CIAO release but is made available as "contributed" software via the CIAO scripts page. Please see this page for installation instructions - such as how to ensure that the parameter file is available.


For a list of known bugs and issues with the XSPEC models, please visit the XSPEC bugs page.

See Also

list_model_components, list_models, load_xscflux, load_xsclumin, load_xscpflux, load_xsgsmooth, load_xsireflect, load_xskdblur, load_xskdblur2, load_xskerrconv, load_xslsmooth, load_xspartcov, load_xsrdblur, load_xsreflect, load_xsrfxconv, load_xsrgsxsrc, load_xssimpl, load_xsvashift, load_xsvmshift, load_xsxilconv, load_xszashift, load_xszmshift, models, tablemodel, xs