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 $77.2_{-9.4}^{+25.4}\%$ of this emission at energies above $\sim$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.

17 pages, 6 figures

References in corpus (14)

• The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV
• The Spectrum of the Isotropic Diffuse Gamma-Ray Emission Derived From First-Year Fermi Large Area Telescope Data
• Background model systematics for the Fermi GeV excess
• The Fermi-LAT high-latitude Survey: Source Count Distributions and the Origin of the Extragalactic Diffuse Background
• The Origin of the Extragalactic Gamma-Ray Background and Implications for Dark-Matter Annihilation
• Star-forming galaxies as the origin of diffuse high-energy backgrounds: Gamma-ray and neutrino connections, and implications for starburst history
• A Comprehensive Search for Dark Matter Annihilation in Dwarf Galaxies
• Cosmic Gamma-Ray Background from Star-Forming Galaxies
• Joint anisotropy and source count constraints on the contribution of blazars to the diffuse gamma-ray background
• Diffuse gamma-ray emission from galactic pulsars
• High-energy neutrinos from radio galaxies
• High-energy gamma-ray and neutrino backgrounds from clusters of galaxies and radio constraints
• Cross-Correlation of Cosmic Shear and Extragalactic Gamma-ray Background: Constraints on the Dark Matter Annihilation Cross-Section
• Tomography of the Fermi-LAT gamma-ray diffuse extragalactic signal via cross-correlations with galaxy catalogs

Cited by in corpus (31)

• Constraints on Decaying Dark Matter from the Isotropic Gamma-Ray Background
• Energetics of High-Energy Cosmic Radiations
• Robust Constraints and Novel Gamma-Ray Signatures of Dark Matter That Interacts Strongly With Nucleons
• The angular power spectrum of the diffuse gamma-ray emission as measured by the Fermi Large Area Telescope and constraints on its Dark Matter interpretation
• Deciphering Contributions to the Extragalactic Gamma-Ray Background from 2 GeV to 2 TeV
• Progress in high-energy cosmic ray physics
• A Case for Radio Galaxies as the Sources of IceCube's Astrophysical Neutrino Flux
• Active Galactic Nuclei and the Origin of IceCube's Diffuse Neutrino Flux
• Star-Forming Galaxies Significantly Contribute to the Isotropic Gamma-Ray Background
• Evidence of TeV Halos Around Millisecond Pulsars
• Revisiting AGN as the Source of IceCube's Diffuse Neutrino Flux
• The Extragalactic Gamma-Ray Background from Core Dominated Radio Galaxies
• Hard X-ray selected giant radio galaxies - I. The X-ray properties and radio connection
• Radio/X-ray monitoring of the broad-line radio galaxy 3C 382. High-energy view with XMM-Newton and NuSTAR
• Characterizing the local gamma-ray Universe via angular cross-correlations
• IceCube Neutrinos from Hadronically Powered Gamma-Ray Galaxies
• High energy emission component, population, and contribution to the extragalactic gamma-ray background of gamma-ray emitting radio galaxies
• Astrophysical interpretation of the anisotropies in the unresolved gamma-ray background
• How bright can the brightest neutrino source be?
• Measurement of redshift dependent cross correlation of HSC clusters and Fermi $\gamma$ rays
• Gamma Ray Signals from Cosmic Ray Scattering on Axion-Like Particles
• High-Energy Gamma Rays and Neutrinos from Nearby Radio Galaxies
• Harnessing the Population Statistics of Subhalos to Search for Annihilating Dark Matter
• Gamma-ray Production in the Extended Halo of the Galaxy and Possible Implications for the Origin of Galactic Cosmic Rays
• Gamma-Rays from Star Forming Activity Appear to Outshine Misaligned Active Galactic Nuclei
• Limits on Early Matter Domination from the Isotropic Gamma-Ray Background
• Inversion of stellar spectral radiative properties based on multiple star catalogues
• The Contribution From TeV Halos to the Isotropic Gamma-Ray Background
• A geomagnetic filter for the Fermi-LAT background
• Tracing Signatures of Modified Gravity in Redshift-Space Galaxy Bispectrum Multipoles: Prospects for Euclid
• Diffuse continuum emission and large extended sources at MeV energies