The throughput calibration of the VERITAS telescopes

The VERITAS Collaboration

Research output: Contribution to journalConference articlepeer-review


Imaging atmospheric Cherenkov telescopes are continuously exposed to varying weather conditions that have short and long-term effects on their response to Cherenkov light from extensive air showers. This work presents the implementation of a throughput calibration method for the VERITAS telescopes taking into account changes in the optical response and detector performance over time. Different methods to measure the total throughput of the instrument, which depend on mirror reflectivites and PMT camera gain and efficiency, are discussed as well as the effect of its evolution on energy thresholds, effective collection areas, and energy reconstruction. The application of this calibration in the VERITAS data analysis chain is discussed, including the validation using Monte Carlo simulations and observations of the Crab Nebula.

Original languageEnglish (US)
Article number721
JournalProceedings of Science
StatePublished - Mar 18 2022
Event37th International Cosmic Ray Conference, ICRC 2021 - Virtual, Berlin, Germany
Duration: Jul 12 2021Jul 23 2021

Bibliographical note

Funding Information:
This research is supported by grants from the U.S. Department of Energy Office of Science, the U.S. National Science Foundation and the Smithsonian Institution, by NSERC in Canada, and by the Helmholtz Association in Germany. This research used resources provided by the Open Science Grid, which is supported by the National Science Foundation and the U.S. Department of Energy’s Office of Science, and resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility operated under Contract No. DE-AC02-05CH11231. We acknowledge the excellent work of the technical support staff at the Fred Lawrence Whipple Observatory and at the collaborating institutions in the construction and operation of the instrument.

Publisher Copyright:
© 2021 Copyright owned by the author(s) under the terms of the Creative Commons.


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