Constraints on the galactic halo dark matter from fermi-lat diffuse measurements
2012 (English)In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 761, no 2, 91- p.Article in journal (Refereed) Published
We have performed an analysis of the diffuse gamma-ray emission with the Fermi Large Area Telescope (LAT) in the Milky Way halo region, searching for a signal from dark matter annihilation or decay. In the absence of a robust dark matter signal, constraints are presented. We consider both gamma rays produced directly in the dark matter annihilation/decay and produced by inverse Compton scattering of the e(+)/e(-) produced in the annihilation/decay. Conservative limits are derived requiring that the dark matter signal does not exceed the observed diffuse gamma-ray emission. A second set of more stringent limits is derived based on modeling the foreground astrophysical diffuse emission using the GALPROP code. Uncertainties in the height of the diffusive cosmic-ray halo, the distribution of the cosmic-ray sources in the Galaxy, the index of the injection cosmic-ray electron spectrum, and the column density of the interstellar gas are taken into account using a profile likelihood formalism, while the parameters governing the cosmic-ray propagation have been derived from fits to local cosmic-ray data. The resulting limits impact the range of particle masses over which dark matter thermal production in the early universe is possible, and challenge the interpretation of the PAMELA/Fermi-LAT cosmic ray anomalies as the annihilation of dark matter.
Place, publisher, year, edition, pages
2012. Vol. 761, no 2, 91- p.
dark matter, Galaxy: halo, gamma rays: diffuse background, methods: statistical
IdentifiersURN: urn:nbn:se:kth:diva-110056DOI: 10.1088/0004-637X/761/2/91ISI: 000312090300010ScopusID: 2-s2.0-84870842972OAI: oai:DiVA.org:kth-110056DiVA: diva2:585710
FunderKnut and Alice Wallenberg Foundation
QC 201301102013-01-102013-01-102013-01-10Bibliographically approved