Very high energy emission sources beyond the Galaxy

Abstract

Abstract. Active Galactic Nuclei (AGN) are considered as potential extragalactic sources of very and ultra high energy cosmic rays. According to theoretical predictions cosmic ray acceleration can take place at the shock created by the expanding cocoons around active galactic nuclei as well as at AGN jets. The measurements of AGN TeV spectra, the variability time scale of TeV emission can provide essential information on the dynamics of AGN jets, the localization of acceleration region and an estimation of its size. SHALON observations yielded data on extragalactic sources of different AGN types in the energy range of 800 GeV-100 TeV. The data from SHALON observations are compared with those from other experiments at high and very high energies.

Probing of extragalactic background light with TeV gamma‐ray observations

“…Among them are BL Lac type, Seyfert Galaxy, BLRG, and FSRQs (Table 1). The energy spectra, emission maps, and spectral energy distributions at E > 800 GeV for each of sources (Sinitsyna 2000; Sinitsyna et al 2016, 2017; Sinitsyna & Sinitsyna 2013) are obtained. The redshifts of SHALON TeV γ ‐ray AGNi range from 0.018 to 1.375.…”