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. GammaLib supports So far the analysis of data obtained with CGRO/COMPTEL, Fermi/LAT, INTEGRAL/SPI and Cherenkov telescopes (CTA, H.E.S.S., MAGIC, VERITAS).

GammaLib does not rely on any third-party software with the exception of HEASARC’s cfitsio library that is the basis of the FITS file interface. All other functionalities are implemented natively.

GammaLib is developed by a team of enthousiastic gamma-ray astronomers with support from engineers.

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 Astrophysics Source Code Library (ASCL) identifier


You may also reference the software by its Digital Object Identifier (DOI) on Zenodo, which is


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.