GammaLib is a versatile toolbox for the scientific analysis of astronomical gamma-ray data. It consists of a C++ library and a Python module that exposes the full functionality of the library to Python. The library provides an abstract data analysis framework that is independent of any specific gamma-ray telescope. Instrument specific aspects, such as handling of data formats and response functions, are implemented as isolated and well defined modules sharing an identical abstract interface. This enables a joint multi-instrument analysis of data, allowing for consistent broad-band spectral fitting or imaging. So far, GammaLib supports analysis of data obtained with CGRO/COMPTEL, Fermi/LAT, INTEGRAL/SPI and Cherenkov telescopes (CTA, H.E.S.S., MAGIC, VERITAS).

Except for HEASARC’s cfitsio library that is used to implement the FITS interface, GammaLib does not rely on any third-party software. All functionalities are implemented natively.

GammaLib is developed by a team of enthousiastic gamma-ray astronomers with support from engineers. We regularily organise coding sprints where key developers but also newcomers meet to discuss the developments and next steps, and advance with the coding of the software.

Acknowledging or citing GammaLib

If you use GammaLib for work/research presented in a publication we ask you to include the formal reference

in your paper as well as the identifier ascl:1110.007 of the code in the Astrophysics Source Code Library (ASCL). You can also reference GammaLib via


In addition please add the following acknowledgment:

This research made use of GammaLib, a community-developed toolbox for the scientific analysis of astronomical gamma-ray data.

If the journal allows this, you can also include a link to http://cta.irap.omp.eu/gammalib/ in addition to the above text.

If you are giving a presentation or talk featuring work/research that makes use of GammaLib, we suggest using this logo on your title slide:


And to see who published an article using GammaLib you may check the following link.


GammaLib is free software distributed under the GNU GPL license version 3.