sherpa.astro.ui.load_xstable_model(modelname, filename, etable=False)

Load a XSPEC table model.

Create an additive (‘atable’, [1]), multiplicative (‘mtable’, [2]), or exponential (‘etable’, [3]) XSPEC table model component. These models may have multiple model parameters.

Changed in version 4.16.0: Parameters with negative DELTA values are now made frozen, to match XSPEC. Support for models which use the ESCALE keyword has been added.

Changed in version 4.14.0: The etable argument has been added to allow exponential table models to be used.

  • modelname (str) – The identifier for this model component.

  • filename (str) – The name of the FITS file containing the data, which should match the XSPEC table model definition [4].

  • etable (bool, optional) – Set if this is an etable (as there’s no way to determine this from the file itself). Defaults to False.


See also


Load a 1D convolution model.


Create a PSF model


Load a set of templates and use it as a model component.


Load tabular or image data and use it as a model component.


Set the source model expression for a data set.


Define the convolved model expression for a data set.


There is no support for table models that provide multiple spectra per parameter: that is, those with the NXFLTEXP keyword set.

NASA’s HEASARC site contains a link to community-provided XSPEC table models.


  1. https://heasarc.gsfc.nasa.gov/docs/xanadu/xspec/manual/XSmodelAtable.html

  2. https://heasarc.gsfc.nasa.gov/docs/xanadu/xspec/manual/XSmodelMtable.html

  3. https://heasarc.gsfc.nasa.gov/docs/xanadu/xspec/manual/XSmodelEtable.html

  4. K. A. Arnaud, I. M. George & A. F. Tennant, “The OGIP Spectral File Format”


Load in the XSPEC table model from the file ‘bbrefl_1xsolar.fits’ and create a model component labelled ‘xtbl’, which is then used in a source expression:

>>> load_xstable_model('xtbl', 'bbrefl_1xsolar.fits')
>>> set_source(xsphabs.gal * xtbl)
>>> print(xtbl)

Load in an XSPEC etable model:

>>> load_xstable_model('etbl', 'etable.mod', etable=True)