A Robust Method for Treating Astrophysical Mismodeling in Dark Matter Annihilation Searches of Dwarf Spheroidal Galaxies

Abstract

Fermi-LAT observations have strongly constrained dark matter annihilation through the joint-likelihood analysis of dwarf spheroidal galaxies (dSphs). These constraints are expected to be robust because dSphs have measurable dark matter content and produce negligible astrophysical emission. However, each dSph is dim, with a predicted flux that typically falls below the accuracy of the background model. We show that this significantly diminishes the reliability of previous joint-likelihood algorithms, and develop an improved analysis that directly accounts for the effect of background mismodeling. This method produces more robust limits and detections of dark matter in both real and mock data. We calculate improved limits on the dark matter annihilation cross-section, which differ by nearly a factor of two from previous analyses - despite examining identical data.

6 Pages, 4 Figures (Appendix adds 4 Pages, 2 Figures)

References in corpus (37)

• Searching for Dark Matter Annihilation from Milky Way Dwarf Spheroidal Galaxies with Six Years of Fermi-LAT Data
• Precise Relic WIMP Abundance and its Impact on Searches for Dark Matter Annihilation
• Constraining Dark Matter Models from a Combined Analysis of Milky Way Satellites with the Fermi Large Area Telescope
• The Characterization of the Gamma-Ray Signal from the Central Milky Way: A Compelling Case for Annihilating Dark Matter
• Searching for Dark Matter Annihilation in Recently Discovered Milky Way Satellites with Fermi-LAT
• Detection of a Gamma-Ray Source in the Galactic Center Consistent with Extended Emission from Dark Matter Annihilation and Concentrated Astrophysical Emission
• Dark Matter Constraints from Observations of 25 Milky Way Satellite Galaxies with the Fermi Large Area Telescope
• Dark Matter and Pulsar Model Constraints from Galactic Center Fermi-LAT Gamma Ray Observations
• The Fermi Galactic Center GeV Excess and Implications for Dark Matter
• Fermi-LAT Observations of High-Energy Gamma-Ray Emission Toward the Galactic Center
• Exclusion of canonical WIMPs by the joint analysis of Milky Way dwarfs with Fermi
• Novel dark matter constraints from antiprotons in the light of AMS-02
• The Luminosity Function of Fermi-detected Flat-Spectrum Radio Quasars
• Possible dark matter annihilation signal in the AMS-02 antiproton data
• A Robust Excess in the Cosmic-Ray Antiproton Spectrum: Implications for Annihilating Dark Matter
• A Comprehensive Search for Dark Matter Annihilation in Dwarf Galaxies
• Indication of Gamma-ray Emission from the Newly Discovered Dwarf Galaxy Reticulum II
• Dark matter profiles and annihilation in dwarf spheroidal galaxies: prospectives for present and future gamma-ray observatories - I. The classical dSphs
• Spherical Jeans analysis for dark matter indirect detection in dwarf spheroidal galaxies - Impact of physical parameters and triaxiality
• Dark matter annihilation and decay from non-spherical dark halos in the Galactic dwarf satellites
• Simple J-Factors and D-Factors for Indirect Dark Matter Detection
• Dark Matter in Dwarf Spheroidal Galaxies and Indirect Detection: A Review
• Scaling Relations for Dark Matter Annihilation and Decay Profiles in Dwarf Spheroidal Galaxies
• The Origin of Segue 1
• On The Gamma-Ray Emission From Reticulum II and Other Dwarf Galaxies
• Stringent Constraints On The Dark Matter Annihilation Cross Section From Subhalo Searches With The Fermi Gamma-Ray Space Telescope
• Dark matter line search using a joint analysis of dwarf galaxies with the Fermi Gamma-ray Space Telescope
• A model-independent analysis of the Fermi Large Area Telescope gamma-ray data from the Milky Way dwarf galaxies and halo to constrain dark matter scenarios
• A critical reassessment of particle Dark Matter limits from dwarf satellites
• Star-Forming Galaxies Significantly Contribute to the Isotropic Gamma-Ray Background
• The Isotropic Radio Background and Annihilating Dark Matter
• Model-independent constraints on dark matter annihilation in dwarf spheroidal galaxies
• Indirect Dark Matter Detection for Flattened Dwarf Galaxies
• Is The Gamma-Ray Source 3FGL J2212.5+0703 A Dark Matter Subhalo?
• Estimating the GeV Emission of Millisecond Pulsars in Dwarf Spheroidal Galaxies
• Dwarf spheroidal J-factors without priors: A likelihood-based analysis for indirect dark matter searches
• Improving the Sensitivity of Gamma-Ray Telescopes to Dark Matter Annihilation in Dwarf Spheroidal Galaxies

Cited by in corpus (4)

• Annihilating Dark Matter Search with 12 Years of Fermi LAT Data in Nearby Galaxy Clusters
• MADHAT: Model-Agnostic Dark Halo Analysis Tool
• Gamma-Rays from Star Forming Activity Appear to Outshine Misaligned Active Galactic Nuclei
• Prospects for annihilating dark matter from M31 and M33 observations with the Cherenkov Telescope Array