The anisotropy of the Fermi-LAT extragalactic sky: still blazars.
ORAL
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 goal is to dissect the composition of the gamma-ray sky and establish the relevance of different classes of source populations in determining the observed UGRB anisotropy level, 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 (FSRQ) at low energies and BL Lacs (BLL) at high energies. The inferred luminosity functions agree well with the extrapolation of the FSRQ and BLL ones obtained from the 4FLG catalog. Bounds on an additional gamma-ray emission due to annihilating dark matter are also derived.
*This work is supported by: `Departments of Excellence 2018-2022' grant awarded by the Italian Ministry of Education, University and Research (\textsc{miur}) L.\ 232/2016; Research grant `The Anisotropic Dark Universe' No.\ CSTO161409, funded by Compagnia di Sanpaolo and University of Turin; Research grant TAsP (Theoretical Astroparticle Physics) funded \textsc{infn}; Research grant `The Dark Universe: A Synergic Multimessenger Approach' No.\ 2017X7X85K funded by \textsc{miur}; Research grant ``Deciphering the high-energy sky via cross correlation'' funded by the agreement ASI-INAF n. 2017-14-H.0; Research grant ``From Darklight to Dark Matter: understanding the galaxy/matter connection to measure the Universe'' No. 20179P3PKJ funded by MIUR; the material is based upon work supported by NASA under award number 80GSFC21M0002.
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Presenters
Michela Negro
University of Maryland, Baltimore County
Authors
Michela Negro
University of Maryland, Baltimore County
Michael Korsmeier
The Oskar Klein Centre, Department of Physics, Stockholm University
