Radio Galaxies Dominate the High-Energy Diffuse Gamma-Ray Background
Abstract
It has been suggested that unresolved radio galaxies and radio quasars (sometimes referred to as misaligned active galactic nuclei) could be responsible for a significant fraction of the observed diffuse gamma-ray background. In this study, we use the latest data from the Fermi Gamma-Ray Space Telescope to characterize the gamma-ray emission from a sample of 51 radio galaxies. In addition to those sources that had previously been detected using Fermi data, we report here the first statistically significant detection of gamma-ray emission from the radio galaxies 3C 212, 3C 411, and B3 0309+411B. Combining this information with the radio fluxes, radio luminosity function, and redshift distribution of this source class, we find that radio galaxies dominate the diffuse gamma-ray background, generating of this emission at energies above 1 GeV. We discuss the implications of this result and point out that it provides support for scenarios in which IceCube's high-energy astrophysical neutrinos also originate from the same population of radio galaxies.
Cite
@article{arxiv.1604.08505,
title = {Radio Galaxies Dominate the High-Energy Diffuse Gamma-Ray Background},
author = {Dan Hooper and Tim Linden and Alejandro Lopez},
journal= {arXiv preprint arXiv:1604.08505},
year = {2016}
}
Comments
17 pages, 6 figures