Journal article
Gamma-ray observations under bright moonlight with VERITAS
Astroparticle physics, Vol.91(C), pp.34-43
05/2017
DOI: 10.1016/j.astropartphys.2017.03.001
Abstract
Imaging atmospheric Cherenkov telescopes (IACTs) are equipped with sensitive photomultiplier tube (PMT) cameras. Exposure to high levels of background illumination degrades the efficiency of and potentially destroys these photo-detectors over time, so IACTs cannot be operated in the same configuration in the presence of bright moonlight as under dark skies. Since September 2012, observations have been carried out with the VERITAS IACTs under bright moonlight (defined as about three times the night-sky-background (NSB) of a dark extragalactic field, typically occurring when Moon illumination > 35%) in two observing modes, firstly by reducing the voltage applied to the PMTs and, secondly, with the addition of ultra-violet (UV) bandpass filters to the cameras. This has allowed observations at up to about 30 times previous NSB levels (around 80% Moon illumination), resulting in 30% more observing time between the two modes over the course of a year. These additional observations have already allowed for the detection of a flare from the 1ES 1727 + 502 and for an observing program targeting a measurement of the cosmic-ray positron fraction. We provide details of these new observing modes and their performance relative to the standard VERITAS observations.
Details
- Title: Subtitle
- Gamma-ray observations under bright moonlight with VERITAS
- Creators
- S Archambault - McGill UniversityA Archer - University of WashingtonW Benbow - Harvard UniversityR Bird - University of California, BerkeleyE Bourbeau - McGill UniversityA Bouvier - University of California, BerkeleyM Buchovecky - University of California, BerkeleyV Bugaev - University of WashingtonJ.V Cardenzana - Iowa State UniversityM Cerruti - Harvard UniversityL Ciupik - Adler PlanetariumM.P Connolly - Ollscoil na Gaillimhe – University of GalwayW Cui - Purdue University West LafayetteM.K Daniel - Harvard UniversityM Errando - University of WashingtonA Falcone - Pennsylvania State UniversityQ Feng - McGill UniversityJ.P Finley - Purdue University West LafayetteH Fleischhack - DESY, Platanenallee 6, 15738 Zeuthen, GermanyL Fortson - University of MinnesotaA Furniss - California State University, East BayG.H Gillanders - Ollscoil na Gaillimhe – University of GalwayS Griffin - McGill UniversityD Hanna - McGill UniversityO Hervet - University of California, BerkeleyJ Holder - University of DelawareG Hughes - Harvard UniversityT.B Humensky - Columbia UniversityM Hütten - DESY, Platanenallee 6, 15738 Zeuthen, GermanyC.A Johnson - University of California, BerkeleyP Kaaret - University of IowaP Kar - University of UtahM Kertzman - DePauw UniversityD Kieda - University of UtahM Krause - DESY, Platanenallee 6, 15738 Zeuthen, GermanyM.J Lang - Ollscoil na Gaillimhe – University of GalwayT.T.Y Lin - McGill UniversityG Maier - DESY, Platanenallee 6, 15738 Zeuthen, GermanyS McArthur - Purdue University West LafayetteP Moriarty - Ollscoil na Gaillimhe – University of GalwayR Mukherjee - Columbia UniversityD Nieto - Columbia UniversityS O’Brien - University College DublinR.A Ong - University of California, BerkeleyA.N Otte - Georgia Institute of TechnologyN Park - University of ChicagoM Pohl - University of PotsdamA Popkow - University of California, BerkeleyE Pueschel - University College DublinJ Quinn - University College DublinK Ragan - McGill UniversityP.T Reynolds - Cork Institute of TechnologyG.T Richards - Georgia Institute of TechnologyE Roache - Harvard UniversityC Rulten - University of MinnesotaI Sadeh - DESY, Platanenallee 6, 15738 Zeuthen, GermanyG.H Sembroski - Purdue University West LafayetteK Shahinyan - University of MinnesotaD Staszak - University of ChicagoI Telezhinsky - University of PotsdamS Trepanier - McGill UniversityS.P Wakely - University of ChicagoA Weinstein - Iowa State UniversityP Wilcox - University of IowaD.A Williams - University of California, BerkeleyB Zitzer - McGill University
- Resource Type
- Journal article
- Publication Details
- Astroparticle physics, Vol.91(C), pp.34-43
- DOI
- 10.1016/j.astropartphys.2017.03.001
- ISSN
- 0927-6505
- eISSN
- 1873-2852
- Publisher
- Elsevier B.V
- Grant note
- DOI: 10.13039/100006132, name: U.S. Department of Energy Office of Science; DOI: 10.13039/100000001, name: U.S. National Science Foundation; DOI: 10.13039/100000014, name: Smithsonian Institution; DOI: 10.13039/501100000038, name: NSERC; name: DGPP; DOI: 10.13039/501100008530, name: European Regional Development Fund (ERDF)
- Language
- English
- Date published
- 05/2017
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984199845102771
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