GammaLib and ctools

A software framework for the analysis of astronomical gamma-ray data

¹ Institut de Recherche en Astrophysique et Planétologie, 9 avenue Colonel-Roche, 31028 Toulouse Cedex 4, France
² Department of Physics, Humboldt University Berlin, Newtonstr. 15, 12489 Berlin, Germany
³ Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany
⁴ Deutsches Elektronen-Synchrotron, Platanenallee 6, 15738 Zeuthen, Germany
⁵ AGH University of Science and Technology, ACC Cyfronet AGH, ul. Nawojki 11, PO Box 386, 30-950 Kraków 23, Poland
⁶ CEA/IRFU/SAp, CEA Saclay, Bat 709, Orme des Merisiers, 91191 Gif-sur-Yvette, France
⁷ Laboratoire d’Annecy-le-Vieux de Physique des Particules, 9 chemin de Bellevue, BP 110, 74941 Annecy-le-Vieux Cedex, France
⁸ Institut de Fisica d’Altes Energies, The Barcelona Institute of Science and Technology, Campus UAB, 08193 Bellaterra, Spain

Received: 29 April 2016
Accepted: 1 June 2016

Abstract

The field of gamma-ray astronomy has seen important progress during the last decade, yet to date no common software framework has been developed for the scientific analysis of gamma-ray telescope data. We propose to fill this gap by means of the GammaLib software, a generic library that we have developed to support the analysis of gamma-ray event data. GammaLib was written in C++ and all functionality is available in Python through an extension module. Based on this framework we have developed the ctools software package, a suite of software tools that enables flexible workflows to be built for the analysis of Imaging Air Cherenkov Telescope event data. The ctools are inspired by science analysis software available for existing high-energy astronomy instruments, and they follow the modular ftools model developed by the High Energy Astrophysics Science Archive Research Center. The ctools were written in Python and C++, and can be either used from the command line via shell scripts or directly from Python. In this paper we present the GammaLib and ctools software versions 1.0 that were released at the end of 2015. GammaLib and ctools are ready for the science analysis of Imaging Air Cherenkov Telescope event data, and also support the analysis of Fermi-LAT data and the exploitation of the COMPTEL legacy data archive. We propose using ctools as the science tools software for the Cherenkov Telescope Array Observatory.