Instrument response function (IRF) functionality (gammapy.irf)

Introduction

gammapy.irf handles instrument response functions (IRFs):

• Effective area (AEFF)
• Energy dispersion (EDISP)
• Point spread function (PSF)

Most of the formats defined at IACT IRF are supported. Otherwise, at the moment, there is very little support for Fermi-LAT or other instruments.

Most users will not use gammapy.irf directly, but will instead use IRFs as part of their spectrum, image or cube analysis to compute exposure and effective EDISP and PSF for a given dataset.

Most (at some point maybe all) classes in gammapy.irf have an gammapy.utils.nddata.NDDataArray as data attribute to support interpolation.

Getting Started

see data_iact.html for an example how to access IACT IRFs.

Using gammapy.irf

If you’d like to learn more about using gammapy.irf, read the following sub-pages:

• IRF Theory
• Effective area
• Energy dispersion
• Point spread function

Reference/API

gammapy.irf Package

Instrument response functions (IRFs).

Functions

multi_gauss_psf_kernel(psf_parameters[, …])

Create multi-Gauss PSF kernel.

Classes

Background2D(energy_lo, energy_hi, …[, …])	Background 2D.
Background3D(energy_lo, energy_hi, detx_lo, …)	Background 3D.
EffectiveAreaTable(energy_lo, energy_hi, data)	Effective area table.
EffectiveAreaTable2D(energy_lo, energy_hi, …)	2D effective area table.
EnergyDependentMultiGaussPSF(energy_lo, …)	Triple Gauss analytical PSF depending on energy and theta.
EnergyDependentTablePSF(energy, rad[, …])	Energy-dependent radially-symmetric table PSF (gtpsf format).
EnergyDispersion(e_true_lo, e_true_hi, …)	Energy dispersion matrix.
EnergyDispersion2D(e_true_lo, e_true_hi, …)	Offset-dependent energy dispersion matrix.
GaussPSF([sigma])	Extension of Gauss2D PDF by PSF-specific functionality.
HESSMultiGaussPSF(source)	Multi-Gauss PSF as represented in the HESS software.
IRFStacker(list_aeff, list_livetime[, …])	Stack instrument response functions.
PSF3D(energy_lo, energy_hi, offset, rad_lo, …)	PSF with axes: energy, offset, rad.
PSF3DChecker(psf[, d_norm, …])	Automated quality checks for gammapy.irf.PSF3D.
PSFKing(energy_lo, energy_hi, offset, gamma, …)	King profile analytical PSF depending on energy and offset.
SherpaMultiGaussPSF(source)	Multi-Gauss PSF as represented in the Sherpa software.
TablePSF(rad, dp_domega[, spline_kwargs])	Radially-symmetric table PSF.