What the Milky Way’s dwarfs tell us about the Galactic Center extended gamma-ray excess
Name
PhysRevD.97.103007.pdf
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Author(s)
Keeley, Ryan E.
Abazajian, Kevork N.
Kwa, Anna
Safdi, Benjamin R.
Rodd, Nicholas Llewellyn
Date Issued
May 2018
Journal
Physical Review D
Publisher
American Physical Society
Citation
Keeley, Ryan E. et al. "What the Milky Way’s dwarfs tell us about the Galactic Center extended gamma-ray excess." Physical Review D 97, 10 (May 2018): 103007 © 2018 American Physical Society
Version
Final published version
Abstract
The Milky Way’s Galactic Center harbors a gamma-ray excess that is a candidate signal of annihilating dark matter. Dwarf galaxies remain predominantly dark in their expected commensurate emission. In this work we quantify the degree of consistency between these two observations through a joint likelihood analysis. In doing so we incorporate Milky Way dark matter halo profile uncertainties, as well as an accounting of diffuse gamma-ray emission uncertainties in dark matter annihilation models for the Galactic Center extended gamma-ray excess (GCE) detected by the Fermi Gamma-Ray Space Telescope. The preferred range of annihilation rates and masses expands when including these unknowns. Even so, using two recent determinations of the Milky Way halo’s local density leaves the GCE preferred region of single-channel dark matter annihilation models to be in strong tension with annihilation searches in combined dwarf galaxy analyses. A third, higher Milky Way density determination, alleviates this tension. Our joint likelihood analysis allows us to quantify this inconsistency. We provide a set of tools for testing dark matter annihilation models’ consistency within this combined data set. As an example, we test a representative inverse Compton sourced self-interacting dark matter model, which is consistent with both the GCE and dwarfs.
MIT Department
Massachusetts Institute of Technology. Center for Theoretical Physics
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1103/PhysRevD.97.103007
