Nature of the low-energy, γ-like background for the Cherenkov Telescope Array
arXiv:1710.06980 · doi:10.1016/j.astropartphys.2017.10.005
Abstract
The upcoming Cherenkov Telescope Array (CTA) project is expected to provide unprecedented sensitivity in the low-energy (<~100 GeV) range for Cherenkov telescopes. Most of the remaining background in this energy range results from misidentified hadron showers. In order to fully exploit the potential of the telescope systems it is worthwhile to look for ways to further improve the available analysis methods for γ/hadron separation. We study the composition of the background for the planned CTA-North array by identifying events composed mostly of a single electromagnetic subcascade or double subcascade from a π0 (or another neutral meson) decay. We apply the standard simulation chain and state-of-the-art analysis chain of CTA to evaluate the potential of the standard analysis to reject such events. Simulations show a dominant role of such single subcascade background for CTA up to energies ~70 GeV. We show that a natural way of rejection of such events stems from a shifted location of the shower maximum, and that the standard stereo reconstruction method used by CTA already exploits most of expected separation.
11 pages, 13 figures, accepted for publication in Astroparticle Physics
References in corpus (9)
- 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
- 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
- Gamma-Hadron Separation in Very-High-Energy gamma-ray astronomy using a multivariate analysis method
- Gamma-Hadron Separation Methods for the VERITAS Array of Four Imaging Atmospheric Cherenkov Telescopes
- Cosmic-Ray Events as Background in Imaging Atmospheric Cherenkov Telescopes
- Monte Carlo Studies of Geomagnetic Field Effects on the Imaging Air Cherenkov Technique for the MAGIC Telescope Site
- Natural limit on the gamma/hadron separation for a stand alone air Cherenkov telescope