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Title: Anisotropy probe of galactic and extra-galactic dark matter annihilations

Abstract

We study the flux and the angular power spectrum of gamma rays produced by dark matter (DM) annihilations in the Milky Way (MW) and in extra-galactic halos. The annihilation signal receives contributions from: (a) the smooth MW halo, (b) resolved and unresolved substructures in the MW, (c) external DM halos at all redshifts, including (d) their substructures. Adopting a self-consistent description of local and extra-galactic substructures, we compute the angular power spectrum of gamma-ray anisotropies and show that, quite independently from the prescription used for the concentration parameters c(M,z), an interesting signature of DM annihilations could soon be discovered by the Fermi LAT satellite at low multipoles, l{approx}100, assuming a particle physics scenario that does not violate gamma-ray constraints from the Galactic center. The DM contribution to the angular power spectrum is dominated by MW substructures (with mass M{>=}10{sup 4}M{sub {center_dot}}), while, at least for the substructures' models that we have adopted, the contribution of extra-galactic annihilations is negligible at all scales. MW subhalos also dominate the annihilation flux in the majority of the sky, with the smooth galactic halo being brighter only in the very central region.

Authors:
; ; ;  [1]
  1. University of Padova and INFN sezione di Padova, via Marzolo 8, 35131 Padova, Italy and Institut d'Astrophysique de Paris, boulevard Arago 89bis, 75014 Paris (France)
Publication Date:
OSTI Identifier:
21316206
Resource Type:
Journal Article
Journal Name:
Physical Review. D, Particles Fields
Additional Journal Information:
Journal Volume: 80; Journal Issue: 2; Other Information: DOI: 10.1103/PhysRevD.80.023518; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0556-2821
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ANISOTROPY; ANNIHILATION; GALAXIES; GAMMA RADIATION; MASS; MILKY WAY; MULTIPOLES; NONLUMINOUS MATTER; PARTICLES; RED SHIFT; SATELLITES; SPECTRA

Citation Formats

Fornasa, Mattia, Pieri, Lidia, Bertone, Gianfranco, Branchini, Enzo, Institut d'Astrophysique de Paris, UMR 7095-CNRS, Universite Pierre et Marie Curie, boulevard Arago 89bis, 75014 Paris, and Department of Physics, Universita di Roma Tre, via della Vasca Navale 84, 00146, Rome. Anisotropy probe of galactic and extra-galactic dark matter annihilations. United States: N. p., 2009. Web. doi:10.1103/PHYSREVD.80.023518.
Fornasa, Mattia, Pieri, Lidia, Bertone, Gianfranco, Branchini, Enzo, Institut d'Astrophysique de Paris, UMR 7095-CNRS, Universite Pierre et Marie Curie, boulevard Arago 89bis, 75014 Paris, & Department of Physics, Universita di Roma Tre, via della Vasca Navale 84, 00146, Rome. Anisotropy probe of galactic and extra-galactic dark matter annihilations. United States. https://doi.org/10.1103/PHYSREVD.80.023518
Fornasa, Mattia, Pieri, Lidia, Bertone, Gianfranco, Branchini, Enzo, Institut d'Astrophysique de Paris, UMR 7095-CNRS, Universite Pierre et Marie Curie, boulevard Arago 89bis, 75014 Paris, and Department of Physics, Universita di Roma Tre, via della Vasca Navale 84, 00146, Rome. 2009. "Anisotropy probe of galactic and extra-galactic dark matter annihilations". United States. https://doi.org/10.1103/PHYSREVD.80.023518.
@article{osti_21316206,
title = {Anisotropy probe of galactic and extra-galactic dark matter annihilations},
author = {Fornasa, Mattia and Pieri, Lidia and Bertone, Gianfranco and Branchini, Enzo and Institut d'Astrophysique de Paris, UMR 7095-CNRS, Universite Pierre et Marie Curie, boulevard Arago 89bis, 75014 Paris and Department of Physics, Universita di Roma Tre, via della Vasca Navale 84, 00146, Rome},
abstractNote = {We study the flux and the angular power spectrum of gamma rays produced by dark matter (DM) annihilations in the Milky Way (MW) and in extra-galactic halos. The annihilation signal receives contributions from: (a) the smooth MW halo, (b) resolved and unresolved substructures in the MW, (c) external DM halos at all redshifts, including (d) their substructures. Adopting a self-consistent description of local and extra-galactic substructures, we compute the angular power spectrum of gamma-ray anisotropies and show that, quite independently from the prescription used for the concentration parameters c(M,z), an interesting signature of DM annihilations could soon be discovered by the Fermi LAT satellite at low multipoles, l{approx}100, assuming a particle physics scenario that does not violate gamma-ray constraints from the Galactic center. The DM contribution to the angular power spectrum is dominated by MW substructures (with mass M{>=}10{sup 4}M{sub {center_dot}}), while, at least for the substructures' models that we have adopted, the contribution of extra-galactic annihilations is negligible at all scales. MW subhalos also dominate the annihilation flux in the majority of the sky, with the smooth galactic halo being brighter only in the very central region.},
doi = {10.1103/PHYSREVD.80.023518},
url = {https://www.osti.gov/biblio/21316206}, journal = {Physical Review. D, Particles Fields},
issn = {0556-2821},
number = 2,
volume = 80,
place = {United States},
year = {Wed Jul 15 00:00:00 EDT 2009},
month = {Wed Jul 15 00:00:00 EDT 2009}
}