# get_bkg_model¶

sherpa.astro.ui.get_bkg_model(id=None, bkg_id=None)

Return the model expression for the background of a PHA data set.

This returns the model expression for the background of a data set, including the instrument response (e.g. ARF and RMF), whether created automatically or explicitly, with set_bkg_full_model.

Parameters
• id (int or str, optional) – The data set to use. If not given then the default identifier is used, as returned by get_default_id.

• bkg_id (int or str, optional) – Identify the background component to use, if there are multiple ones associated with the data set.

Returns

This can contain multiple model components and any instrument response. Changing attributes of this model changes the model used by the data set.

Return type

instance

delete_bkg_model()

Delete the background model expression for a data set.

get_bkg_source()

Return the model expression for the background of a PHA data set.

list_model_ids()

List of all the data sets with a source expression.

set_bkg_model()

Set the background model expression for a PHA data set.

set_bkg_full_model()

Define the convolved background model expression for a PHA data set.

show_bkg_model()

Display the background model expression for a data set.

Examples

Return the background model expression for the default data set, including any instrument response:

>>> bkg = get_bkg_model()