Galactic Center gamma-ray "excess" from an active past of the Galactic Centre?

Abstract

Several groups have recently claimed evidence for an unaccounted gamma-ray excess over {the} diffuse backgrounds at few GeV in {the} Fermi-LAT data in a region around the Galactic Center, consistent with a dark matter annihilation origin. We demonstrate that the main spectral and angular features of this excess can be reproduced if they are mostly due to inverse Compton emission from high-energy electrons injected in a burst event of ~10^52 - 10^53erg roughly O(10^6) years ago. We consider this example as a proof of principle that time-dependent phenomena need to be understood and accounted for - together with detailed diffuse foregrounds and unaccounted "steady state" astrophysical sources - before any robust inference can be made about dark matter signals at the Galactic Center. In addition, we point out that the timescale suggested by our study, which controls both the energy cutoff and the angular extension of the signal, intriguingly matches (together with the energy budget) what is indirectly inferred by other evidences suggesting a very active Galactic Center in the past, for instance related to intense star formation and accretion phenomena.

arXiv comment6 pages, 4 figures. Minor scale correction plus a typo in a figure label. Conclusions unchanged

References in corpus (24)

• The Galactic Center Massive Black Hole and Nuclear Star Cluster
• Giant Gamma-ray Bubbles from Fermi-LAT: AGN Activity or Bipolar Galactic Wind?
• Dark Matter Annihilation in The Galactic Center As Seen by the Fermi Gamma Ray Space Telescope
• Fermi-LAT Observations of the Diffuse Gamma-Ray Emission: Implications for Cosmic Rays and the Interstellar Medium
• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• On The Origin Of The Gamma Rays From The Galactic Center
• Detection of a Gamma-Ray Source in the Galactic Center Consistent with Extended Emission from Dark Matter Annihilation and Concentrated Astrophysical Emission
• Dark Matter and Pulsar Model Constraints from Galactic Center Fermi-LAT Gamma Ray Observations
• Astrophysical and Dark Matter Interpretations of Extended Gamma-Ray Emission from the Galactic Center
• Multi-frequency analysis of neutralino dark matter annihilations in the Coma cluster
• Testing Properties of the Galactic Center Black Hole Using Stellar Orbits
• A comment on the emission from the Galactic Center as seen by the Fermi telescope
• A lower limit of 50 microgauss for the magnetic field near the Galactic Centre
• 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
• Pulsars Cannot Account for the Inner Galaxy's GeV Excess
• The Contribution of Cosmic Rays Interacting With Molecular Clouds to the Galactic Center Gamma-Ray Excess
• A RIAF Interpretation for the Past Higher Activity of the Galactic Center Black Hole and the 511 keV Annihilation Emission
• Millisecond pulsar interpretation of the Galactic center gamma-ray excess
• Traces of past activity in the Galactic Centre
• Bremsstrahlung gamma rays from light Dark Matter
• A Multiwavelength View of a Mass Outflow from the Galactic Center
• Sgr A*: The Optimal Testbed of Strong-Field Gravity
• The Cosmic Ray Population of the Galactic Central Molecular Zone

Cited by in corpus (119)

• The Dawn of FIMP Dark Matter: A Review of Models and Constraints
• Background model systematics for the Fermi GeV excess
• Strong support for the millisecond pulsar origin of the Galactic center GeV excess
• A Tale of Tails: Dark Matter Interpretations of the Fermi GeV Excess in Light of Background Model Systematics
• A review of indirect searches for particle dark matter
• Evidence for Unresolved Gamma-Ray Point Sources in the Inner Galaxy
• The e-ASTROGAM mission (exploring the extreme Universe with gamma rays in the MeV-GeV range)
• Status of the scalar singlet dark matter model
• Dark Nuclei I: Cosmology and Indirect Detection
• Disrupted Globular Clusters Can Explain the Galactic Center Gamma Ray Excess
• 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
• The Galactic Center GeV Excess from a Series of Leptonic Cosmic-Ray Outbursts
• The characteristics of the Galactic center excess measured with 11 years of Fermi-LAT data
• Dark Matter Strikes Back at the Galactic Center
• Challenges in Explaining the Galactic Center Gamma-Ray Excess with Millisecond Pulsars
• Updated cosmic-ray and radio constraints on light dark matter: Implications for the GeV gamma-ray excess at the Galactic center
• Dark Matter Interpretation of the Fermi-LAT Observation Toward the Galactic Center
• Multi-Step Cascade Annihilations of Dark Matter and the Galactic Center Excess
• Multimessenger constraints on the dark matter interpretation of the Fermi-LAT Galactic center excess
• Simulated Milky Way analogues: implications for dark matter indirect searches
• Antiproton constraints on the GeV gamma-ray excess: a comprehensive analysis
• Dark Matter in Dwarf Spheroidal Galaxies and Indirect Detection: A Review
• The Return of the Templates: Revisiting the Galactic Center Excess with Multi-Messenger Observations
• 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
• The High-Energy Tail of the Galactic Center Gamma-Ray Excess
• Probing dark matter annihilation in the Galaxy with antiprotons and gamma rays
• The inert doublet model in the light of Fermi-LAT gamma-ray data: a global fit analysis
• Towards a realistic astrophysical interpretation of the gamma-ray Galactic center excess
• Z' Mediated Dark Matter Models for the Galactic Center Gamma-Ray Excess
• A description of the Galactic Center excess in the Minimal Supersymmetric Standard Model
• Search for Gamma-ray Emission from Dark Matter Annihilation in the Large Magellanic Cloud with the Fermi Large Area Telescope
• Galactic Center Excess in Gamma Rays from Annihilation of Self-Interacting Dark Matter
• Nonthermal Two Component Dark Matter Model for Fermi-LAT $\gamma$-ray excess and 3.55 keV X-ray Line
• WIMP searches with gamma rays in the Fermi era: challenges, methods and results
• VERITAS Observations of the Galactic Center Region at Multi-TeV Gamma-Ray Energies
• Distinguishing Dark Matter from Unresolved Point Sources in the Inner Galaxy with Photon Statistics
• Particle Dark Matter Constraints: the Effect of Galactic Uncertainties
• The GCE in a New Light: Disentangling the $\gamma$-ray Sky with Bayesian Graph Convolutional Neural Networks
• Model-independent analysis of the DAMPE excess
• Improved Cosmic-Ray Injection Models and the Galactic Center Gamma-Ray Excess
• A global fit of the $\gamma$-ray galactic center excess within the scalar singlet Higgs portal model
• Dark matter annihilation radiation in hydrodynamic simulations of Milky Way haloes
• Multimediator models for the galactic center gamma ray excess
• SUSY Implications from WIMP Annihilation into Scalars at the Galactic Centre
• Millisecond pulsar origin of the Galactic center excess and extended gamma-ray emission from Andromeda - a closer look
• Search for Gamma-ray Emission from Dark Matter Annihilation in the Small Magellanic Cloud with the Fermi Large Area Telescope
• Discovery of a New Galactic Center Excess Consistent with Upscattered Starlight
• Gamma-ray and X-ray emission from the Galactic Centre: hints on the nuclear star cluster formation history
• Les Houches Lectures on Indirect Detection of Dark Matter
• Constraining Dark Matter Interactions with Pseudoscalar and Scalar Mediators Using Collider Searches for Multi-jets plus Missing Transverse Energy
• The $\text{Fermi}$-LAT gamma-ray excess at the Galactic Center in the singlet-doublet fermion dark matter model
• The Effective J-Factor of the Galactic Center for Velocity-Dependent Dark Matter Annihilation
• Search for $\gamma$-ray emission from dark matter particle interactions from Andromeda and Triangulum Galaxies with the Fermi Large Area Telescope
• Putting Things Back Where They Belong: Tracing Cosmic-Ray Injection with H2
• Is The Gamma-Ray Source 3FGL J2212.5+0703 A Dark Matter Subhalo?
• Gamma rays from the Galactic Centre region: a review
• Dark matter subhalos and unidentified sources in the Fermi 3FGL source catalog
• Investigating the Uniformity of the Excess Gamma rays towards the Galactic Center Region
• Gamma Rays From Dark Matter Subhalos Revisited: Refining the Predictions and Constraints
• Dim but not entirely dark: Extracting the Galactic Center Excess' source-count distribution with neural nets
• Fermionic Semi-Annihilating Dark Matter
• Active Galactic Nuclei: Boon or Bane for Biota?
• p-wave Annihilating Dark Matter from a Decaying Predecessor and the Galactic Center Excess
• The Spatial Morphology of the Secondary Emission in the Galactic Center Gamma-Ray Excess
• Boxes, Boosts, and Energy Duality: Understanding the Galactic-Center Gamma-Ray Excess through Dynamical Dark Matter
• A Systematic Study of Hidden Sector Dark Matter: Application to the Gamma-Ray and Antiproton Excesses
• Prospects for annihilating Dark Matter towards Milky Way's dwarf galaxies by the Cherenkov Telescope Array
• Analyzing the Gamma-ray Sky with Wavelets
• Confronting Galactic center and dwarf spheroidal gamma-ray observations with cascade annihilation models
• AMS-02 Positron Excess and Indirect Detection of Three-body Decaying Dark Matter
• Pevatron at the Galactic Center: Multi-Wavelength Signatures from Millisecond Pulsars
• Identification of point sources in gamma rays using U-shaped convolutional neural networks and a data challenge
• Saving the MSSM from the Galactic Center Excess
• Light weakly interacting massive particles
• Known Radio Pulsars Do Not Contribute to the Galactic Center Gamma-Ray Excess
• Cosmic-Ray Models of the Ridge-Like Excess of Gamma Rays in the Galactic Center
• Testing Type II Radiative Seesaw Model: from Dark Matter Detection to LHC Signatures
• Dark Higgs Channel for FERMI GeV $\gamma$-ray Excess
• Cosmic-ray antiprotons in the AMS-02 era: A sensitive probe of dark matter
• Robustness of dark matter constraints and interplay with collider searches for New Physics
• Muon g-2 and galactic centre $\gamma$-ray excess in a scalar extension of the 2HDM type-X
• Constraints on dark matter annihilation and decay from the large-scale structure of the nearby universe
• Lepton-Flavor Violating Mediators
• Novel Collider and Dark Matter Phenomenology of a Top-philic Z'
• Wavelet-Based Techniques for the Gamma-Ray Sky
• Dark Matter, Shared Asymmetries, and Galactic Gamma Ray Signals
• Tau Portal Dark Matter models at the LHC
• Robustness of the Galactic Center Excess Morphology Against Masking
• Di-photon excess at LHC and the gamma ray excess at the Galactic Centre
• On the GeV excess in the diffuse γ-ray emission towards the Galactic Center
• Muonphilic Dark Matter explanation of gamma-ray galactic center excess: a comprehensive analysis
• Dark matter implications of the WMAP-Planck Haze
• Probing the Fermi-LAT GeV excess with gravitational waves
• Dark matter substructure cannot explain properties of the Fermi Galactic Centre excess
• Probing the pulsar explanation of the Galactic-Center GeV excess using continuous gravitational-wave searches
• Comparing Galactic Center MSSM dark matter solutions to the Reticulum II gamma-ray data
• What the Milky Way's Dwarfs tell us about the Galactic Center extended excess
• Mind the gap: The discrepancy between simulation and reality drives interpretations of the Galactic Center Excess
• How to calculate dark matter direct detection exclusion limits that are consistent with gamma rays from annihilation in the Milky Way halo
• The Galactic Center Excess from Z3 Scalar Semi-Annihilations
• Interpreting the Fermi-LAT gamma ray excess in the simplified framework
• Towards resolving the Galactic center GeV excess with millisecond-pulsar-like sources using machine learning
• Hidden Higgs Portal Vector Dark Matter for the Galactic Center Gamma-Ray Excess from the Two-Step Cascade Annihilation, and Muon g-2
• Interpretations of galactic center gamma-ray excess confronting the PandaX-II constraints on dark matter-neutron spin-dependent scatterings in the NMSSM
• When Dark Matter interacts with Cosmic Rays or Interstellar Matter: A Morphological Study
• Gamma-ray line constraints on Coy Dark Matter
• Investigating the Fermi Large Area Telescope sensitivity of detecting the characteristics of the Galactic center excess
• Neutrino Mass, Coupling Unification, Verifiable Proton Decay, Vacuum Stability and WIMP Dark Matter in SU(5)
• Galactic Centre as an efficient source of cosmic rays
• Soft Gamma Rays from Heavy WIMPs
• Signatures of Dark Matter in Cosmic-Ray Observations
• Dark matter, extra-terrestrial gamma-rays and the MSSM: a viability study
• Search for dark matter with IACTs and the Cherenkov Telescope Array
• The Galactic Isotropic $\gamma$-ray Background and Implications for Dark Matter
• Possible counterpart signal of the Fermi bubbles at the cosmic-ray positrons
• A Fermi-LAT Study of Globular Cluster Dynamical Evolution in the Milky Way: Millisecond Pulsars as the Probe
• Dark matter properties implied by gamma ray interstellar emission models