DARK MATTER SEARCHES IN THE GAMMA-RAY EXTRAGALACTIC BACKGROUND VIA CROSS-CORRELATIONS WITH GALAXY CATALOGS

Journal Article · Tue Dec 15 04:00:00 EST 2015 · Astrophysical Journal, Supplement Series

DOI:https://doi.org/10.1088/0067-0049/221/2/29· OSTI ID:22520052

Cuoco, Alessandro; Regis, Marco; Fornengo, Nicolao ^[1]; Xia, Jun-Qing ^[2]; Branchini, Enzo ^[3]; Viel, Matteo ^[4]

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1. Dipartimento di Fisica, Università di Torino, via P. Giuria 1, I-10125 Torino (Italy)
2. Department of Astronomy, Beijing Normal University, Beijing 100875 (China)
3. Dipartimento di Matematica e Fisica, Università degli Studi “Roma Tre,” via della Vasca Navale 84, I-00146 Roma (Italy)
4. INAF Osservatorio Astronomico di Trieste, Via G. B. Tiepolo 11, I-34141, Trieste (Italy)

We compare the measured angular cross-correlation between the Fermi-Large Area Telescope γ-ray sky and catalogs of extragalactic objects with the expected signal induced by weakly interacting massive particle (WIMP) dark matter (DM). We include a detailed description of the contribution of astrophysical γ-ray emitters such as blazars, misaligned active galactic nucleus (AGN), and star-forming galaxies, and perform a global fit to the measured cross-correlation. Five catalogs are considered: Sloan Digital Sky Survey (SDSS)-DR6 quasars, Two Micron All Sky Survey galaxies, NRAO VLA Sky Survey radio galaxies, SDSS-DR8 Luminous Red Galaxies, and the SDSS-DR8 main galaxy sample. To model the cross-correlation signal, we use the halo occupation distribution formalism to estimate the number of galaxies of a given catalog in DM halos and their spatial correlation properties. We discuss uncertainties in the predicted cross-correlation signal arising from the DM clustering and WIMP microscopic properties, which set the DM γ-ray emission. The use of different catalogs probing objects at different redshifts significantly reduces, though not completely, the degeneracy among the different γ-ray components. We find that the presence of a significant WIMP DM signal is allowed by the data but not significantly preferred by the fit, although this is mainly due to a degeneracy with the misaligned AGN component. With modest substructure boost, the sensitivity of this method excludes thermal annihilation cross sections at 95% level for WIMP masses up to few tens of GeV. Constraining the low-redshift properties of astrophysical populations with future data will further improve the sensitivity to DM.

• OSTI ID: 22520052
• Journal Information: Astrophysical Journal, Supplement Series, Journal Name: Astrophysical Journal, Supplement Series Journal Issue: 2 Vol. 221; ISSN 0067-0049; ISSN APJSA2
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ANNIHILATION
ASTROPHYSICS
CATALOGS
COMPARATIVE EVALUATIONS
CORRELATIONS
COSMOLOGY
CROSS SECTIONS
GALAXY NUCLEI
GAMMA RADIATION
GEV RANGE
NONLUMINOUS MATTER
PROBES
QUASARS
RADIO GALAXIES
RED SHIFT
STARS
TELESCOPES
UNIVERSE
WIMPS