# unpack_arf¶

sherpa.astro.ui.unpack_arf(arg)

Create an ARF data structure.

Parameters: arg – Identify the ARF: a file name, or a data structure representing the data to use, as used by the I/O backend in use by Sherpa: a TABLECrate for crates, as used by CIAO, or a list of AstroPy HDU objects. arf a sherpa.astro.instrument.ARF1D instance

get_arf()
Return the ARF associated with a PHA data set.
load_arf()
Load an ARF from a file and add it to a PHA data set.
load_bkg_arf()
Load an ARF from a file and add it to the background of a PHA data set.
load_multi_arfs()
Load multiple ARFs for a PHA data set.
load_pha()
Load a file as a PHA data set.
load_rmf()
Load a RMF from a file and add it to a PHA data set.
set_full_model()
Define the convolved model expression for a data set.

Notes

The minimum_energy setting of the ogip section of the Sherpa configuration file determines the behavior when an ARF with a minimum energy of 0 is read in. The default is to replace the 0 by the value 1e-10, which will also cause a warning message to be displayed.

Examples

>>> arf1 = unpack_arf("arf1.fits")
>>> arf2 = unpack_arf("arf2.fits")


Read in an ARF using Crates:

>>> acr = pycrates.read_file("src.arf")
>>> arf = unpack_arf(acr)


Read in an ARF using AstroPy:

>>> hdus = astropy.io.fits.open("src.arf")
>>> arf = unpack_arf(hdus)