Implications of Plasma Beam Instabilities for the Statistics of the Fermi Hard Gamma-ray Blazars and the Origin of the Extragalactic Gamma-Ray Background

Abstract

Fermi has been instrumental in constraining the luminosity function and redshift evolution of gamma-ray bright blazars. This includes limits upon the spectrum and anisotropy of the extragalactic gamma-ray background (EGRB), redshift distribution of nearby Fermi active galactic nuclei (AGN), and the construction of a log(N)-log(S) relation. Based upon these, it has been argued that the evolution of the gamma-ray bright blazar population must be much less dramatic than that of other AGN. However, critical to such claims is the assumption that inverse Compton cascades reprocess emission above a TeV into the Fermi energy range, substantially enhancing the strength of the observed limits. Here we demonstrate that in the absence of such a process, due, e.g., to the presence of virulent plasma beam instabilities that preempt the cascade, a population of TeV-bright blazars that evolve similarly to quasars is consistent with the population of hard gamma-ray blazars observed by Fermi. Specifically, we show that a simple model for the properties and luminosity function is simultaneously able to reproduce their log(N)-log(S) relation, local redshift distribution, and contribution to the EGRB and its anisotropy without any free parameters. Insofar the naturalness of a picture in which the hard gamma-ray blazar population exhibits the strong redshift evolution observed in other tracers of the cosmological history of accretion onto halos is desirable, this lends support for the absence of the inverse Compton cascades and the existence of the beam plasma instabilities.

14 pages, 13 figures, submitted to ApJ

References in corpus (9)

• An Observational Determination of the Bolometric Quasar Luminosity Function
• The Spectrum of the Isotropic Diffuse Gamma-Ray Emission Derived From First-Year Fermi Large Area Telescope Data
• The Cosmic Evolution of Fermi BL Lacertae Objects
• The Imprint of The Extragalactic Background Light in the Gamma-Ray Spectra of Blazars
• The Fermi-LAT high-latitude Survey: Source Count Distributions and the Origin of the Extragalactic Diffuse Background
• Joint anisotropy and source count constraints on the contribution of blazars to the diffuse gamma-ray background
• Gamma-Ray and Neutrino Backgrounds as Probes of the High-Energy Universe: Hints of Cascades, General Constraints, and Implications for TeV Searches
• BL Lac Contribution to the Extragalactic Gamma-Ray Background
• The Arizona Radio Observatory CO Mapping Survey of Galactic Molecular Clouds: III. The Serpens Cloud in CO J=2-1 and 13CO J=2-1 Emission

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• Unveiling the Gamma-ray Source Count Distribution Below the Fermi Detection Limit with Photon Statistics
• The Linear Instability of Dilute Ultrarelativistic $e^{\pm }$ Pair Beams
• Using rotation measure grids to detect cosmological magnetic fields -- a Bayesian approach
• Conditions for the onset of the current filamentation instability in the laboratory
• Fermi-LAT gamma-ray anisotropy and intensity explained by unresolved Radio-Loud Active Galactic Nuclei
• The growth of the longitudinal beam-plasma instability in the presence of an inhomogeneous background
• The role of resonant plasma instabilities in the evolution of blazar induced pair beams
• Angular Power Spectra with Finite Counts
• Bow Ties in the Sky I: The Angular Structure of Inverse Compton Gamma-ray Halos in the Fermi Sky
• Lower Limits on the Anisotropy of the Extragalactic Gamma-Ray Background implied by the 2FGL and 1FHL Catalogs
• Patchy blazar heating: diversifying the thermal history of the intergalactic medium
• Suppression of the TeV pair-beam plasma instability by a tangled weak intergalactic magnetic field
• Bow Ties in the Sky II: Searching for Gamma-ray Halos in the Fermi Sky Using Anisotropy
• Constraints on the Intergalactic Magnetic Field from Bow Ties in the Gamma-ray Sky
• Constraining blazar heating with the 2<z<3 Lyman-$\alpha$ forest
• MeV cosmic-ray electrons modify the TeV pair-beam plasma instability