Mar 18 – 22, 2019
MPI for Nuclear Physics
Europe/Berlin timezone

GammaLib and ctools: A Framework for the Analysis of Astronomical Gamma-ray Datasets

Mar 20, 2019, 2:30 PM
MPI for Nuclear Physics

MPI for Nuclear Physics

Saupfercheckweg 1, 69117 Heidelberg
Talk Wednesday


Josh Cardenzana


ctools is an open source data analysis package targeted towards the upcoming Cherenkov Telescope Array. The tools employ both a three-dimensional likelihood analysis similar to that used in the Fermi Science Tools, and a standard On/Off analysis typical of current generation atmospheric Cherenkov telescopes. Built on top of the GammaLib software, ctools is designed to be easily adapted for use with data from past, present, and future high energy photon-counting detectors. Already, the tools have been applied to H.E.S.S., Fermi-LAT, and COMPTEL data as well as simulated CTA observations. Data from multiple instruments can also be fit simultaneously, an important feature for understanding astrophysical processes across a broad energy range. In terms of the software, GammaLib exists primarily in C++ to optimize computation speed. Python wrappers are used to provide a user-friendly interface to the GammaLib classes. ctools consists of both Python modules and C++ classes that can be accessed via Python wrappers. At a higher level, the individual tools are also designed to be run directly from the command-line. This modular aspect of ctools means it can adapt to suit a range of different analyses workflows. This contribution will focus on the design and development principles behind the ctools and GammaLib software. A demonstration of the capabilities of ctools will also be presented using test data recently released by the H.E.S.S. collaboration.

Primary author

Presentation materials