Flat spectrum radio quasars and BL Lacs dominate the anisotropy of the unresolved gamma-ray background
Loading...
Links to Files
Permanent Link
Author/Creator
Author/Creator ORCID
Date
Type of Work
Department
Program
Citation of Original Publication
Rights
This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.
Attribution 4.0 International (CC BY 4.0)
Attribution 4.0 International (CC BY 4.0)
Subjects
Abstract
We analyze the angular power spectrum (APS) of the unresolved gamma-ray background (UGRB)
emission and combine it with the measured properties of the resolved gamma-ray sources of the Fermi LAT 4FGL catalog. Our goals are to dissect the composition of the gamma-ray sky and to establish the
relevance of different classes of source populations of active galactic nuclei in determining the observed
size of the UGRB anisotropy, especially at low energies. We find that, under physical assumptions for
the spectral energy dispersion, two populations are required to fit APS data, namely flat spectrum
radio quasars (FSRQs) at low energies and BL Lacs (BLLs) at higher energies. The inferred luminosity
functions agree well with the extrapolation of the FSRQ and BLL ones obtained from the 4FLG catalog.
We use these luminosity functions to calculate the UGRB intensity from blazars, finding a contribution
of 20% at 1GeV and 30% above 10 GeV. Finally, bounds on an additional gamma-ray emission due to
annihilating dark matter are derived