Data Formats¶

Note

Since November 2015 there is the Data formats for gamma-ray astronomy project. This page contains extra information about which formats we support in Gammapy and which class corresponds to which format.

Where available and useful existing standards are used, e.g. for spectral data the X-ray community has developed the PHA, ARF and RMF file formats and they have developed powerful tools to work with data in that format.

Overview¶

Here’s an overview of the file formats supported by Gammapy and Gammalib:

Type

Format Name

Gammapy

Gammalib

Events

EVENTS

EventList

GEventList

Effective area

AEFF_2D

EffectiveAreaTable2D

GCTAAeff2D

Effective area

ARF

EffectiveAreaTable

GCTAAeffArf

Energy dispersion

EDISP_2D

EnergyDispersion2D

GCTAEdisp2D

Energy dispersion

RMF

EDispKernel

GCTAEdispRMF

PSF

PSF_2D_GAUSS

EnergyDependentMultiGaussPSF

GCTAPsf2D

PSF

PSF_2D_KING

PSFKing

GCTAPsfKing

PSF

no spec available

TablePSF

GCTAPsfVector

PSF

gtpsf output

EnergyDependentTablePSF

N/A

PSF

psf_table

PSF3D

GCTAPsfTable

PSF

no spec available

N/A

GCTACubePsf

Background

BACKGROUND_3D

Background3D

GCTABackground3D

Background

BACKGROUND_2D

Background2D

N/A

Background

no spec available

N/A

Background

no spec available

N/A

GCTACubeBackground

Exposure

EXPOSURE_3D

Map

GCTACubeExposure

Counts

3D

Map

GCTAEventCube

Counts

Image

Map

GSkyMap

Counts

PHA

RegionNDMap

GPha

Notes¶

• The Gammalib docs contain a nice overview of IRFs here and detailed explanations of some IRF here.

• We probably should unify / shorten the IRF class names in Gammapy.

• There’s quite a few classes in Gammapy that don’t have a well-defined format. We should add a way to serialise every class and document the format for easier interop.

• Maybe add info which format is used by Fermi, HESS HD/PA, CTA?

• For every format there should be one or several test data files. This could even be in a repo that’s shared by Gammalib / Gammapy.