Hensley, Brandon S. and Siegal-Gaskins, Jennifer M. and Vasiliki, Pavlidou (2010) The detectability of dark matter annihilation with fermi using the anisotropy energy spectrum of the gamma-ray background. Astrophysical Journal, 723 (1). pp. 277-284. ISSN 0004-637X. http://resolver.caltech.edu/CaltechAUTHORS:20101213-111539673
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The energy dependence of the anisotropy (the anisotropy energy spectrum) of the large-scale diffuse gamma-ray background can reveal the presence of multiple source populations. Annihilating dark matter in the substructure of the Milky Way halo could give rise to a modulation in the anisotropy energy spectrum of the diffuse gamma-ray emission measured by Fermi, enabling the detection of a dark matter signal. We determine the detectability of a dark-matter-induced modulation for scenarios in which unresolved blazars are the primary contributor to the measured emission above ~1GeV and find that in some scenarios pair-annihilation cross sections on the order of the value expected for thermal relic dark matter can produce a detectable feature. We anticipate that the sensitivity of this technique to specific dark matter models could be improved by tailored likelihood analysis methods.
|Additional Information:||© 2010 American Astronomical Society. Received 2009 December 9; accepted 2010 August 27; published 2010 October 8. We are grateful to Shin’ichiro Ando, Alessandro Cuoco, and Tonia Venters for helpful discussions, and to John Beacom and Anthony Readhead for valuable feedback. B.S.H. thanks CCAPP, and J.M.S.-G. and V.P. thank the Pauli Center for Theoretical Studies at the University of Zürich, for hospitality during the completion of this study. B.S.H. also acknowledges the Summer Undergraduate Research Fellowship (SURF) program at Caltech, and in particular Barbara and Stanley Rawn, Jr. and the Alain Porter Memorial SURF Fellowship for their support. J.S.-G. was supported in part by NSF CAREER Grant PHY- 0547102 (to John Beacom). V.P. acknowledges support for this work provided by NASA through Einstein Postdoctoral Fellowship grant number PF8-90060 awarded by the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for NASA under contract NAS8-03060. This work was partially supported by NASA through the Fermi GI Program grant number NNX09AT74G.|
|Subject Keywords:||dark matter – galaxies: active – Galaxy: structure – gamma rays: diffuse background|
|Classification Code:||PACS: 95.35.+d; 98.70.Rz; 98.35.Gi|
|Official Citation:||Brandon S. Hensley et al 2010 ApJ 723 277 doi: 10.1088/0004-637X/723/1/277|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Benjamin Perez|
|Deposited On:||13 Dec 2010 20:38|
|Last Modified:||26 Dec 2012 12:45|
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