Ground-based gamma-ray astronomy: history and development of techniques

Abstract

Very High Energy (VHE) gamma rays constitute one of the main pillars of high energy astrophysics. Gamma rays are produced under extreme relativistic conditions in the Universe. VHE gamma$ rays can be detected indirectly on the ground. Detection of these energetic photons poses several technological challenges. Firstly, even though gamma rays are highly penetrative, the Earth's atmosphere is opaque to them. Secondly, these gamma rays are to be detected against the overwhelming background of cosmic rays. When a VHE gamma ray arrives at the top of the atmosphere it produces charged secondaries. These charged particles produce Cherenkov flashes in the optical band. Even though the first attempts to detect these Cherenkov flashes were made almost 70 years ago, it took several decades of relentless efforts to streamline the technique. Ground-based VHE gamma-ray astronomy has now established itself as one of the crucial branches of conventional high energy astronomy to study the relativistic Universe. In this article we look back and present a historical perspective followed by a discussion on the current status and finally what lies ahead.

35 pages, 30 figures, accepted for publication in The European Physical Journal Special Topics

References in corpus (13)

• Observations of the Crab Nebula with H.E.S.S
• The major upgrade of the MAGIC telescopes, Part II: A performance study using observations of the Crab Nebula
• Teraelectronvolt emission from the $\gamma$-ray burst GRB 190114C
• A connection between star formation activity and cosmic rays in the starburst galaxy M 82
• The major upgrade of the MAGIC telescopes, Part I: The hardware improvements and the commissioning of the system
• Implementation of the Random Forest Method for the Imaging Atmospheric Cherenkov Telescope MAGIC
• Observation of Pulsed Gamma-rays Above 25 GeV from the Crab Pulsar with MAGIC
• Spatially Resolving the Very High Energy emission from MGRO J2019+37 with VERITAS
• The Sensitivity of HAWC to High-Mass Dark Matter Annihilations
• The TACTIC atmospheric Cherenkov Imaging telescope
• Mrk 421, Mrk 501, and 1ES 1426+428 at 100 GeV with the CELESTE Cherenkov Telescope
• A new solution for mirror coating in $\gamma$-ray Cherenkov Astronomy
• Observations of AGNs using PACT