Auxiliary Response File (ARF)

The Auxiliary Response File (frequenty referred to simply as ARF) defines the telescope efficiency as a function of energy. This is typically a 1D file with units of [cm^2 counts / photon] as a function of photon energy. See the CXC documentation page on ARFs

class pyxsis.xrayspectrum1d.ARF(e_low, e_high, eff_area, exposure=None, fracexpo=1.0)

apply_arf(model, exposure=None)

Fold the spectrum through the auxiliary response file (ARF). The ARF is a single vector encoding the effective area information about the detector. A such, applying the ARF is a simple multiplication with the input spectrum.

Parameters

modelnumpy.ndarray

The model spectrum to which the arf will be applied

exposurefloat, default None

Value for the exposure time. By default, apply_arf will use the exposure keyword from the ARF file. If this exposure time is not correct (for example when simulated spectra use a different exposure time and the ARF from a real observation), one can override the default exposure by setting the exposure keyword to the correct value.

Returns

s_arfnumpy.ndarray

The (model) spectrum after folding, in counts/s/channel

static read(filename, block='SPECRESP')

Load an ARF object from FITS file.

Inputs

filenamestr

Path to the FITS file

blockstr

FITS file block keyword, if the spectral response is stored under an extension other than “SPECRESP”

Returns

The ARF object that is represented by the FITS file