Last modified: December 2018

AHELP for CIAO 4.11 Sherpa v1


Context: models


lorentzian smoothing. XSpec convolution model *Experimental*.


Lorentzian smoothing with a variable width, which varies as the Index power of the energy. The width at 6 keV is set with the SigAt6keV parameter.

dC(E) = n(E) S(E) A(X) dX

n(E) = 1.0 / ( 2 pi [ (E-X)^2 + (S(E)/2)^2 ] )

S(E) = SigAt6keV (E/6)^Index

xslsmooth Parameters

Number Name Description
1 SigAt6keV The sigma for the lorentzian at 6 keV (in keV)
2 Index Power of energy for sigma variation

Loading the X-Spec convolution models

Please see ahelp xsconvolve for information on how to load the model.


XSpec version

This information is taken from the XSpec User's Guide. Version 12.10.0e of the XSpec models is supplied with CIAO 4.11.


sherpa> from sherpa_contrib.xspec.xsconvolve import load_xslsmooth
sherpa> load_xslsmooth("lsm")
sherpa> set_source(lsm(
sherpa> lsm.index = 1.5
sherpa> lsm.sigat6kev = 0.5

The powerlaw is convolved by a lorentzian whose sigma varies as Energy^1.5 and is 0.5 keV at 6 keV.

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_xspartcov, load_xsrdblur, load_xsreflect, load_xsrfxconv, load_xsrgsxsrc, load_xssimpl, load_xsvashift, load_xsvmshift, load_xsxilconv, load_xszashift, load_xszmshift, models, tablemodel, xs, xsconvolve