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arXiv · 2108.11701

A New Gamma-ray Emitting Population of FR0 Radio Galaxies

Vaidehi S. Paliya
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Abstract

The enigmatic class of Fanaroff-Riley type 0 (FR0) radio galaxies is emerging as the missing link between the faint yet numerous population of compact radio sources in nearby galaxies and the canonical Fanaroff-Riley classification scheme. This letter reports the first gamma-ray identification of three FR0 galaxies above 1 GeV using more than a decade of the Fermi Large Area Telescope observations. A cumulative gamma-ray emission at >5 sigma significance was also detected from the gamma-ray unresolved FR0 sources using the stacking technique, suggesting the FR0 population to be a gamma-ray emitter as a whole. The multi-frequency properties of the gamma-ray detected sources are similar to other FR0s, thus indicating the high-energy radiation to originate from misaligned jets. Given their large abundance, FR0 radio galaxies are proposed as plausible candidates for IceCube-detected neutrinos and the results presented in this letter may provide crucial constraints on their gamma-ray production mechanism and the origin of cosmic neutrinos.

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Vaidehi S. Paliya. 2021-08-26. A New Gamma-ray Emitting Population of FR0 Radio Galaxies. https://doi.org/10.3847/2041-8213%2Fac2143

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