The Return of the Templates: Revisiting the Galactic Center Excess with Multi-Messenger Observations

Abstract

The Galactic center excess (GCE) remains one of the most intriguing discoveries from the Fermi Large Area Telescope (LAT) observations. We revisit the characteristics of the GCE by first producing a new set of high-resolution galactic diffuse gamma-ray emission templates, which are ultimately due to cosmic-ray interactions with the interstellar medium. Using multi-messenger observations we constrain the properties of the galactic diffuse emission. The broad properties of the GCE that we find in this work are qualitatively unchanged despite the introduction of this new set of templates, though its quantitative features appear mildly different than those obtained in previous analyses. In particular, we find a high-energy tail at higher significance than previously reported. This tail is very prominent in the northern hemisphere, and less so in the southern hemisphere. This strongly affects one prominent interpretation of the excess: known millisecond pulsars are incapable of producing this high-energy emission, even in the relatively softer southern hemisphere, and are therefore disfavored as the sole explanation of the GCE. The annihilation of dark matter particles of mass $40_{-7}^{+10}$ GeV (95$\%$ CL) to $b$ quarks with a cross-section of $\sigma v=1.4_{-0.3}^{+0.6}\times 10^{-26}$ cm${}^3$s${}^{-1}$ provides a good fit to the excess especially in the relatively cleaner southern sky. Dark matter of the same mass range annihilating to $b$ quarks or heavier dark matter particles annihilating to heavier Standard Model bosons can combine with millisecond pulsars to provide a good fit to the southern hemisphere emission. As part of this paper, we make publicly available all of our templates and the data covariance matrix we have generated to account for systematic uncertainties.[abridged]

arXiv commentv1: 41 pages, 23 figures and 9 tables. v2: 42 pages 24 figures and 9 tables. Reflects PRD final version with an additional figure. Diffuse flux maps available at https://zenodo.org/record/6423495#.YogWjS-ZPGI

References in corpus (161)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• emcee: The MCMC Hammer
• The Structure of Cold Dark Matter Halos
• MultiNest: an efficient and robust Bayesian inference tool for cosmology and particle physics
• dynesty: A Dynamic Nested Sampling Package for Estimating Bayesian Posteriors and Evidences
• Fermi Large Area Telescope Fourth Source Catalog
• Searching for Dark Matter Annihilation from Milky Way Dwarf Spheroidal Galaxies with Six Years of Fermi-LAT Data
• Propagation of cosmic-ray nucleons in the Galaxy
• Giant Gamma-ray Bubbles from Fermi-LAT: AGN Activity or Bipolar Galactic Wind?
• The Second Fermi Large Area Telescope Catalog of Gamma-ray Pulsars
• The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV
• Dark Matter Annihilation in The Galactic Center As Seen by the Fermi Gamma Ray Space Telescope
• Precise Relic WIMP Abundance and its Impact on Searches for Dark Matter Annihilation
• Fermi-LAT Observations of the Diffuse Gamma-Ray Emission: Implications for Cosmic Rays and the Interstellar Medium
• Update on scalar singlet dark matter
• Diffuse Galactic continuum gamma rays. A model compatible with EGRET data and cosmic-ray measurements
• On The Origin Of The Gamma Rays From The Galactic Center
• Acceleration of petaelectronvolt protons in the Galactic Centre
• The Characterization of the Gamma-Ray Signal from the Central Milky Way: A Compelling Case for Annihilating Dark Matter
• Solar Modulation of Cosmic Rays
• 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
• A novel determination of the local dark matter density
• The Nuclear Bulge of the Galaxy. III. Large-Scale Physical Characteristics of Stars and Interstellar Matter
• NE2001.I. A New Model for the Galactic Distribution of Free Electrons and its Fluctuations
• Background model systematics for the Fermi GeV excess
• Secondary antiprotons and propagation of cosmic rays in the Galaxy and heliosphere
• Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Galactic Foreground Emission
• Dark Matter and Pulsar Model Constraints from Galactic Center Fermi-LAT Gamma Ray Observations
• Planck 2018 results. IV. Diffuse component separation
• The Fermi Galactic Center GeV Excess and Implications for Dark Matter
• A New $\Sigma -D$ Relation and Its Application to the Galactic Supernova Remnant Distribution
• The dark matter density at the Sun's location
• Fermi-LAT Observations of High-Energy Gamma-Ray Emission Toward the Galactic Center
• Astrophysical and Dark Matter Interpretations of Extended Gamma-Ray Emission from the Galactic Center
• Strong support for the millisecond pulsar origin of the Galactic center GeV excess
• Constraints on cosmic-ray propagation models from a global Bayesian analysis
• The Spectrum and Morphology of the Fermi Bubbles
• The Vertical Structure of Warm Ionised Gas in the Milky Way
• Dynamic nested sampling: an improved algorithm for parameter estimation and evidence calculation
• A Tale of Tails: Dark Matter Interpretations of the Fermi GeV Excess in Light of Background Model Systematics
• Evidence for Unresolved Gamma-Ray Point Sources in the Inner Galaxy
• The Fermi Haze: A Gamma-Ray Counterpart to the Microwave Haze
• GALPROP WebRun: an internet-based service for calculating galactic cosmic ray propagation and associated photon emissions
• Novel dark matter constraints from antiprotons in the light of AMS-02
• Galactic Searches for Dark Matter
• Science with e-ASTROGAM (A space mission for MeV-GeV gamma-ray astrophysics)
• The Fermi Bubbles: Giant, Multi-Billion-Year-Old Reservoirs of Galactic Center Cosmic Rays
• Inverse Compton Origin of the Hard X-Ray and Soft Gamma-Ray Emission from the Galactic Ridge
• Simplified Dark Matter Models for the Galactic Center Gamma-Ray Excess
• Scalar Simplified Models for Dark Matter
• A Renormalizable Model for the Galactic Center Gamma Ray Excess from Dark Matter Annihilation
• Detection of large-scale X-ray bubbles in the Milky Way halo
• Extended Anomalous Foreground Emission in the WMAP 3-Year Data
• Possible Evidence For Dark Matter Annihilation In The Inner Milky Way From The Fermi Gamma Ray Space Telescope
• The Consistency of Fermi-LAT Observations of the Galactic Center with a Millisecond Pulsar Population in the Central Stellar Cluster
• The Fermi Bubbles. I. Possible Evidence for Recent AGN Jet Activity in the Galaxy
• Search for Gamma-Ray Emission from DES Dwarf Spheroidal Galaxy Candidates with Fermi-LAT Data
• An Updated Analysis of Inert Higgs Doublet Model in light of the Recent Results from LUX, PLANCK, AMS-02 and LHC
• Improved GRAVITY astrometric accuracy from modeling of optical aberrations
• The distribution of cosmic-ray sources in the Galaxy, gamma-rays, and the gradient in the CO-to-H2 relation
• Bayesian analysis of cosmic-ray propagation: evidence against homogeneous diffusion
• GeV excess in the Milky Way: The Role of Diffuse Galactic gamma ray Emission template
• Galactic synchrotron emission with cosmic ray propagation models
• Evidence for dark matter contraction and a Salpeter IMF in a massive early-type galaxy
• Inverse Compton Emission from Galactic Supernova Remnants: Effect of the Interstellar Radiation Field
• Cosmic Ray Protons in the Inner Galaxy and the Galactic Center Gamma-Ray Excess
• Limits on Dark Matter Annihilation Signals from the Fermi LAT 4-year Measurement of the Isotropic Gamma-Ray Background
• Pulsars Cannot Account for the Inner Galaxy's GeV Excess
• A Robust Excess in the Cosmic-Ray Antiproton Spectrum: Implications for Annihilating Dark Matter
• Extended gamma-ray emission from Coy Dark Matter
• Interpretation of AMS-02 electrons and positrons data
• HAWC Observations Strongly Favor Pulsar Interpretations of the Cosmic-Ray Positron Excess
• Solution of heliospheric propagation: unveiling the local interstellar spectra of cosmic ray species
• Hidden On-Shell Mediators for the Galactic Center Gamma-Ray Excess
• A Comprehensive Search for Dark Matter Annihilation in Dwarf Galaxies
• The Fermi Bubbles: Supersonic AGN Jets with Anisotropic Cosmic Ray Diffusion
• Indication of Gamma-ray Emission from the Newly Discovered Dwarf Galaxy Reticulum II
• Galactic Bulge Preferred Over Dark Matter for the Galactic Center Gamma-Ray Excess
• Disrupted Globular Clusters Can Explain the Galactic Center Gamma Ray Excess
• WIMPs at the Galactic Center
• Model-Independent Indirect Detection Constraints on Hidden Sector Dark Matter
• Fitting the Galactic Center Gamma-Ray Excess with Cascade Annihilations
• Galactic Center gamma-ray "excess" from an active past of the Galactic Centre?
• Millisecond pulsars and the Galactic Center gamma-ray excess: the importance of luminosity function and secondary emission
• Radial distribution of the diffuse gamma-ray emissivity in the galactic disk
• Flavored Dark Matter and the Galactic Center Gamma-Ray Excess
• Sensitivity Projections for Dark Matter Searches with the Fermi Large Area Telescope
• Origin of the Fermi Bubble
• Fermi gamma-ray `bubbles' from stochastic acceleration of electrons
• A Unified Model of the Fermi Bubbles, Microwave Haze, and Polarized Radio Lobes: Reverse Shocks in the Galactic Center's Giant Outflows
• The characteristics of the Galactic center excess measured with 11 years of Fermi-LAT data
• The Fermi-LAT GeV Excess Traces Stellar Mass in the Galactic Bulge
• The Galactic Center GeV Excess from a Series of Leptonic Cosmic-Ray Outbursts
• Dark Matter Strikes Back at the Galactic Center
• The Effective Hooperon
• Scrutinizing the evidence for dark matter in cosmic-ray antiprotons
• Fermi Large Area Telescope Fourth Source Catalog Data Release 2
• Anisotropic inverse Compton scattering in the Galaxy
• Indications for a high-rigidity break in the cosmic-ray diffusion coefficient
• Pseudoscalar Portal Dark Matter
• 3D Distribution of Molecular Gas in the Barred Milky Way
• Hidden Sector Dark Matter Models for the Galactic Center Gamma-Ray Excess
• A Predictive Analytic Model for the Solar Modulation of Cosmic Rays
• Challenges in Explaining the Galactic Center Gamma-Ray Excess with Millisecond Pulsars
• Imprints of Cosmic Rays in Multifrequency Observations of the Interstellar Emission
• Cosmic Ray Electrons, Positrons and the Synchrotron emission of the Galaxy: consistent analysis and implications
• TeV Halos are Everywhere: Prospects for New Discoveries
• Updated cosmic-ray and radio constraints on light dark matter: Implications for the GeV gamma-ray excess at the Galactic center
• Prospects to verify a possible dark matter hint in cosmic antiprotons with antideuterons and antihelium
• Dark Matter Interpretation of the Fermi-LAT Observation Toward the Galactic Center
• Z-portal dark matter
• What Does The PAMELA Antiproton Spectrum Tell Us About Dark Matter?
• The Fermi Bubbles. II. The Potential Roles of Viscosity and Cosmic Ray Diffusion in Jet Models
• The Fermi Bubbles as Starburst Wind Termination Shocks
• Foreground Mismodeling and the Point Source Explanation of the Fermi Galactic Center Excess
• Antiproton constraints on the GeV gamma-ray excess: a comprehensive analysis
• Prospects for indirect dark matter searches with MeV photons
• Radio detection prospects for a bulge population of millisecond pulsars as suggested by Fermi LAT observations of the inner Galaxy
• On The Gamma-Ray Emission From Reticulum II and Other Dwarf Galaxies
• Deciphering the local Interstellar spectra of secondary nuclei with GALPROP/HelMod framework and a hint for primary lithium in cosmic rays
• The High-Energy Tail of the Galactic Center Gamma-Ray Excess
• Galactic halo size in the light of recent AMS-02 data
• Spurious Point Source Signals in the Galactic Center Excess
• Extracting limits on Dark Matter annihilation from gamma-ray observations towards dwarf spheroidal galaxies
• Very local interstellar spectra for galactic electrons, protons and helium
• A Search for Dark Matter Annihilation in Galaxy Groups
• Towards a realistic astrophysical interpretation of the gamma-ray Galactic center excess
• A signature of anisotropic cosmic-ray transport in the gamma-ray sky
• Search for Gamma-ray Emission from Dark Matter Annihilation in the Large Magellanic Cloud with the Fermi Large Area Telescope
• The Enigmatic Galactic Center Excess: Spurious Point Sources and Signal Mismodeling
• Secondary antiprotons as a Galactic Dark Matter probe
• A New Mask for An Old Suspect: Testing the Sensitivity of the Galactic Center Excess to the Point Source Mask
• Distinguishing Dark Matter from Unresolved Point Sources in the Inner Galaxy with Photon Statistics
• Power requirements for cosmic ray propagation models involving diffusive reacceleration; estimates and implications for the damping of interstellar turbulence
• Dark matter for excess of AMS-02 positrons and antiprotons
• The GCE in a New Light: Disentangling the $\gamma$-ray Sky with Bayesian Graph Convolutional Neural Networks
• Millisecond Pulsars, TeV Halos, and Implications For The Galactic Center Gamma-Ray Excess
• A neural simulation-based inference approach for characterizing the Galactic Center $\gamma$-ray excess
• Young Pulsars and the Galactic Center GeV Gamma-ray Excess
• Galactic dark matter search via phenomenological astrophysics modeling
• Dissecting the Gamma-Ray Background in Search of Dark Matter
• Possible Evidence for the Stochastic Acceleration of Secondary Antiprotons by Supernova Remnants
• Evidence of TeV Halos Around Millisecond Pulsars
• Implications on cosmic ray injection and propagation parameters from Voyager/ACE/AMS-02 nucleus data
• Studying the Milky Way Pulsar Population with Cosmic-Ray Leptons
• Comparing the Galactic Bulge and Galactic Disk Millisecond Pulsars
• Investigating the Uniformity of the Excess Gamma rays towards the Galactic Center Region
• Dim but not entirely dark: Extracting the Galactic Center Excess' source-count distribution with neural nets
• Time-dependent AMS-02 electron-positron fluxes in an extended force-field model
• Analyzing the Gamma-ray Sky with Wavelets
• Pevatron at the Galactic Center: Multi-Wavelength Signatures from Millisecond Pulsars
• Searching For Pulsars Associated With the Fermi GeV Excess
• Anti-Deuterons and Anti-Helium Nuclei from Annihilating Dark Matter
• Millisecond Pulsars Modify the Radio-SFR Correlation in Quiescent Galaxies
• The Milky Way, Coming into Focus: Precision Astrometry Probes its Evolution, and its Dark Matter
• Bayesian analysis of the hardening in AMS-02 nuclei spectra
• A Compound Poisson Generator approach to Point-Source Inference in Astrophysics
• Origin of Cosmic Ray Electrons and Positrons
• Search for TeV emission from the Fermi Bubbles at low Galactic latitudes with H.E.S.S. inner Galaxy survey observations
• Constraining the Charge-Sign and Rigidity-Dependence of Solar Modulation

Cited by in corpus (36)

• Exploring dark matter spike distribution around the Galactic centre with stellar orbits
• Explaining the GeV antiproton/$\gamma -$ray excesses and W-boson mass anomaly in an inert two Higgs doublet model
• Dark Matter Candidates and Searches
• Robust inference of the Galactic centre gamma-ray excess spatial properties
• Constraints on dark matter annihilation and decay from the large-scale structure of the nearby universe
• A Phantom Menace: On the Morphology of the Galactic Center Excess
• The Sensitivity of Future Gamma-Ray Telescopes to Primordial Black Holes
• Robustness of the Galactic Center Excess Morphology Against Masking
• Constraints on dark matter annihilation from the FAST observation of the Coma Berenices dwarf galaxy
• Probing the pulsar explanation of the Galactic-Center GeV excess using continuous gravitational-wave searches
• Updated constraints on WIMP dark matter annihilation by radio observations of M31
• Mind the gap: The discrepancy between simulation and reality drives interpretations of the Galactic Center Excess
• On the gamma-ray emission from the core of the Sagittarius dwarf galaxy
• A New Determination of the Millisecond Pulsar Gamma-Ray Luminosity Function and Implications for the Galactic Center Gamma-Ray Excess
• Multi-Component Imaging of the Fermi Gamma-ray Sky in the Spatio-spectral Domain
• Revisiting GeV-scale annihilating dark matter with the AMS-02 positron fraction
• Towards resolving the Galactic center GeV excess with millisecond-pulsar-like sources using machine learning
• Constraining the Charge-, Time- and Rigidity-Dependence of Cosmic-Ray Solar Modulation with AMS-02 Observations during Solar Cycle 24
• Observing Signals of Spectral Features in the Cosmic-Ray Positrons and Electrons from Milky Way Pulsars
• Dark Matter Is The New BBN
• The Cherenkov Telescope Array Will Test Whether Pulsars Generate the Galactic Center Gamma-Ray Excess
• Applying Simulation-Based Inference to Spectral and Spatial Information from the Galactic Center Gamma-Ray Excess
• Reanalysis of the Systematic Uncertainties in Cosmic-Ray Antiproton Flux
• Search for GeV-scale Dark Matter from the Galactic Center with IceCube-DeepCore
• Detectability of dark matter density distribution via gravitational waves from binary black holes in the Galactic center
• Dark Matter and Electroweak Baryogenesis with Spontaneous $CP$ Violation in the Early Universe
• Observations of the Fermi bubbles and the Galactic center excess with the DArk Matter Particle Explorer
• Search for dark matter with IACTs and the Cherenkov Telescope Array
• Possible counterpart signal of the Fermi bubbles at the cosmic-ray positrons
• Characterizing the Expected Behavior of Non-Poissonian Template Fitting
• GammaBayes: a Bayesian pipeline for dark matter detection with CTA
• Millisecond Pulsars in Globular Clusters and Implications for the Galactic Center Gamma-Ray Excess
• On the Energy Distribution of the Galactic Center Excess' Sources
• The contribution to Galactic Centre γ-ray excess from cluster-born millisecond pulsars. Constraints from direct N-body simulations
• High Energy Emission from the Galactic Center
• A GeV Gamma-Ray Spectral Excess in the Fermi Blazar 4FGL J0136.5+3906