get_bkg_arf
- sherpa.astro.ui.get_bkg_arf(id=None)
Return the background ARF associated with a PHA data set.
This is for the case when there is only one background component and one background response. If this does not hold, use
get_arf
and use thebkg_id
andresp_id
arguments.- 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
.- Returns:
arf – This is a reference to the ARF, rather than a copy, so that changing the fields of the object will change the values in the data set.
- Return type:
a
sherpa.astro.instrument.ARF1D
instance
See also
fake_pha
Simulate a PHA data set from a model.
load_bkg_arf
Load an ARF from a file and add it to the background of a PHA data set.
load_pha
Load a file as a PHA data set.
set_full_model
Define the convolved model expression for a data set.
set_arf
Set the ARF for use by a PHA data set.
set_rmf
Set the RMF for use by a PHA data set.
unpack_arf
Read in an ARF from a file.
Examples
Return the exposure field of the ARF from the background of the default data set:
>>> get_bkg_arf().exposure
Copy the ARF from the default data set to data set 2, as the first component:
>>> arf1 = get_bkg_arf() >>> set_arf(2, arf1, bkg_id=1)