Sherpa Models

Sherpa | Sherpa (optical) | XSPEC | Other

The models available in Sherpa are listed below. The full list may be accessed within Sherpa using the list_models() command.

Sherpa models

Sherpa optical models

The following Sherpa models are designed for use with spectra or SEDs at optical wavelengths, which means that where relevant, position, line width, and other similar model parameters have units of Angstroms.

absorptionedge
absorptiongaussian
absorptionlorentz
absorptionvoigt has been removed in CIAO 4.13; please use voigt1d or pseudovoigt1d
accretiondisk
blackbody
bremsstrahlung
brokenpowerlaw
ccm
emissiongaussian
emissionlorentz
emissionvoigt has been removed in CIAO 4.13; please use voigt1d or pseudovoigt1d
fm
lmc
logabsorption
logemission
opticalgaussian
polynomial
powerlaw
recombination
seaton
sm
smc
xgal

Models from XSPEC

Sherpa 4.17 includes the "additive", "multiplicative", and "convolution" models of XSpec version 12.14.0k. The XSpec model names have the prefix "xs", e.g. XSpec phabs model is called "xsphabs"; see "ahelp xs" for general information on the XSpec models in Sherpa.

The load_xstable_model function is used to read in XSPEC table models. Do not use load_table_model for this. The sherpa.astro.io.xstable module contains code that can be used to create your own XSPEC table model. Please contact the CXC Helpdesk if you are interested in using this code!

XSPEC user models can be converted using the convert_xspec_user_model script.

Other models

Models can also be created using Python code with the commands load_user_model and add_user_pars, or the add_model function which is used to add a model class to Sherpa (in which case the model behaves like the in-built Sherpa models.

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