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Title: What the Milky Way’s dwarfs tell us about the Galactic Center extended gamma-ray excess

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.

Authors:
 [1];  [1];  [1];  [2];  [3]
  1. Univ. of California, Irvine, CA (United States). Dept. of Physics and Astronomy
  2. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Center for Theoretical Physics
  3. Univ. of Michigan, Ann Arbor, MI (United States). Michigan Center for Theoretical Physics. Dept. of Physics
Publication Date:
Research Org.:
Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP)
OSTI Identifier:
1541170
Alternate Identifier(s):
OSTI ID: 1436829
Grant/Contract Number:  
SC0013999; SC0012567; DESC00012567; DESC0013999
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 97; Journal Issue: 10; Journal ID: ISSN 2470-0010
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS

Citation Formats

Keeley, Ryan E., Abazajian, Kevork N., Kwa, Anna, Rodd, Nicholas L., and Safdi, Benjamin R. What the Milky Way’s dwarfs tell us about the Galactic Center extended gamma-ray excess. United States: N. p., 2018. Web. doi:10.1103/physrevd.97.103007.
Keeley, Ryan E., Abazajian, Kevork N., Kwa, Anna, Rodd, Nicholas L., & Safdi, Benjamin R. What the Milky Way’s dwarfs tell us about the Galactic Center extended gamma-ray excess. United States. https://doi.org/10.1103/physrevd.97.103007
Keeley, Ryan E., Abazajian, Kevork N., Kwa, Anna, Rodd, Nicholas L., and Safdi, Benjamin R. 2018. "What the Milky Way’s dwarfs tell us about the Galactic Center extended gamma-ray excess". United States. https://doi.org/10.1103/physrevd.97.103007. https://www.osti.gov/servlets/purl/1541170.
@article{osti_1541170,
title = {What the Milky Way’s dwarfs tell us about the Galactic Center extended gamma-ray excess},
author = {Keeley, Ryan E. and Abazajian, Kevork N. and Kwa, Anna and Rodd, Nicholas L. and Safdi, Benjamin R.},
abstractNote = {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.},
doi = {10.1103/physrevd.97.103007},
url = {https://www.osti.gov/biblio/1541170}, journal = {Physical Review D},
issn = {2470-0010},
number = 10,
volume = 97,
place = {United States},
year = {Thu May 10 00:00:00 EDT 2018},
month = {Thu May 10 00:00:00 EDT 2018}
}

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Cited by: 7 works
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Works referenced in this record:

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Works referencing / citing this record:

Handling the uncertainties in the Galactic Dark Matter distribution for particle Dark Matter searches
journal, March 2019


A global analysis of dark matter signals from 27 dwarf spheroidal galaxies using 11 years of Fermi-LAT observations
journal, February 2020