2015/12/31 by Yoshiyuki Inoue, Yasuyuki T. Tanaka · 9 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Background radiation #Blazar #COSMIC cancer database #Cosmic background radiation #Cosmic infrared background #Cosmic ray #Dark Matter and Cosmic Phenomena #Extragalactic background light #Flux (metallurgy) #Galaxy #Particle physics theoretical and experimental studies #astro-ph.CO #astro-ph.HE
paper · pdf · doi:10.3847/0004-637x/818/2/187
published in The Astrophysical Journal 818(2), 187 (IOP Publishing) · 6 pages, 4 figures, 2 tables, accepted for publication in ApJ
arxiv created 2016/01/17 · openalex publication_date 2016/02/18 · arxiv updated 2016/03/09 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
ABSTRACT The Fermi gamma-ray space telescope has revolutionized our understanding of the cosmic gamma-ray background radiation in the GeV band. However, investigation on the cosmic TeV gamma-ray background radiation still remains sparse. Here, we report the lower bound on the cosmic TeV gamma-ray background spectrum placed by the cumulative flux of individual detected extragalactic TeV sources including blazars, radio galaxies, and starburst galaxies. The current limit on the cosmic TeV gamma-ray background above 0.1 TeV is obtained as 2.8 × 10 −8 ( E /100 GeV) −0.55 exp(− E /2100GeV)[GeV cm −2 s −1 sr −1 ] < E 2 dN / dE < 1.1 × 10 −7 ( E /100 GeV) −0.49 [GeV cm −2 s −1 sr −1 ], where the upper bound is set by requirement that the cascade flux from the cosmic TeV gamma-ray background radiation can not exceed the measured cosmic GeV gamma-ray background spectrum. Two nearby blazars, Mrk 421 and Mrk 501, explain ∼70% of the cumulative background flux at 0.8–4 TeV, while extreme blazars start to dominate at higher energies. We also provide the cumulative background flux from each population, i.e., blazars, radio galaxies, and starburst galaxies which will be the minimum requirement for their contribution to the cosmic TeV gamma-ray background radiation.