Modifications of a method for low energy gamma-ray incident angle reconstruction in the GAMMA-400 gamma-ray telescope

[摘要] The GAMMA-400 gamma-ray telescope is designed to measure the gamma-ray fluxes in the energy range from ∼20 MeV to ∼1 TeV, performing a sensitive search for high-energy gamma-ray emission when annihilating or decaying dark matter particles. Such measurements will be also associated with the following scientific goals: searching for new and studying known Galactic and extragalactic discrete high-energy gamma-ray sources (supernova remnants, pulsars, accreting objects, microquasars, active galactic nuclei, blazars, quasars). It will be possible to study their structure with high angular resolution and measuring their energy spectra and luminosity with high-energy resolution; identify discrete gamma-ray sources with known sources in other energy ranges. The major advantage of the GAMMA-400 instrument is excellent angular and energy resolutions for gamma rays above 10 GeV. The gamma-ray telescope angular and energy resolutions for the main aperture at 100-GeV gamma rays are ∼0.01% and ∼1%, respectively. The motivation of presented results is to improve physical characteristics of the GAMMA-400 gamma-ray telescope in the energy range of ∼20-100 MeV, most unexplored range today. Such observations are crucial today for a number of high-priority problems faced by modern astrophysics and fundamental physics, including the origin of chemical elements and cosmic rays, the nature of dark matter, and the applicability range of the fundamental laws of physics. To improve the reconstruction accuracy of incident angle for low-energy gamma rays the special analysis of topology of pair-conversion events in thin layers of converter performed. Choosing the pair-conversion events with more precise vertical localization allows us to obtain significantly better angular resolution in comparison with previous and current space and ground-based experiments. For 50-MeV gamma rays the GAMMA-400 gamma-ray telescope angular resolution is better than 50.

[发布机构] National Research Nuclear University MEPhI, Moscow Engineering Physics Institute, Kashirskoe highway 31, Moscow; 115409, Russia^1;Lebedev Physical Institute, Russian Academy of Sciences, Leninskiy pr. 53, Moscow; 119991, Russia^2;Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Via Valerio, 2, Trieste; 34127, Italy^3;Istituto Nazionale di Fisica Nucleare, Sezione di Firenze, Via G. Sansone 1, Firenze; 50019, Italy^4;Scientific Research Institute for System Analysis, Russian Academy of Sciences, Nakhimovskiy pr. 36, Moscow; 117218, Russia^5;Taras Shevchenko National University, Volodymyrska Street, 64/13, Kyiv; 01601, Ukraine^6;Lviv Center of Institute of Space Research, Naukova Street, 5-A, Lviv, Ukraine^7;CRESST/GSFC, University of Maryland, College Park; MD; 20742, United States^8;Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 450 Serra Mall, Stanford; 94305, United States; (10) Istituto Nazionale di Fisica Nucleare, Sezione di Roma 2, Physics Department, University of Rome Tor Vergata, Via della Ricerca Scientifica, 1, Rome; 00133, Italy; (11) Istituto Nazionale di Astrofisica IASF, Physics Department, University of Rome Tor Vergata, Area della Ricerca-via Piero Gobetti, 101, Bologna; 40129, Italy^9

[效力级别] 天文学 [学科分类] 天文学(综合)

[关键词] Active galactic nuclei;Dark matter particles;High angular resolutions;High-energy resolution;Low energy gamma ray;Physical characteristics;Reconstruction accuracy;Vertical localization