Towards a realistic astrophysical interpretation of the gamma-ray Galactic center excess

Abstract

A spherical-symmetric gamma-ray emission from the central region of the Galaxy has been recently identified in Fermi-LAT data, and initially associated to dark matter particle annihilations. Guided by the evidence for a high gas density in the inner kpc of the Galaxy correlated with a very large Supernova rate, and hence with ongoing cosmic-ray acceleration, we investigate instead the possibility of addressing this excess in terms of ordinary cosmic-ray sources and standard steady-state diffusion. We alter the source term, and consistently the correlated gamma-ray emissions, in the context of a template-fitting analysis. We focus on a region of interest (ROI) defined as: $|l|<20^{\circ };2^{\circ }<|b|<20^{\circ },$ with $l$ and $b$ the Galactic longitude and latitude coordinates. We analyze in detail the overall goodness of the fit of our framework, and perform a detailed direct comparison against data examining profiles in different directions. Remarkably, the test statistic of the fit related to our scenario turns out to be as good as the Dark Matter one in the ROI here considered.

25 pages, 10 figures in Journal of Cosmology and Astroparticle Physics, Volume 2015, December 2015

References in corpus (42)

• Searching for Dark Matter Annihilation from Milky Way Dwarf Spheroidal Galaxies with Six Years of Fermi-LAT Data
• Giant Gamma-ray Bubbles from Fermi-LAT: AGN Activity or Bipolar Galactic Wind?
• The spectrum of isotropic diffuse gamma-ray emission between 100 MeV and 820 GeV
• The Parkes multibeam pulsar survey: VI. Discovery and timing of 142 pulsars and a Galactic population analysis
• Background model systematics for the Fermi GeV excess
• The Spectrum and Morphology of the Fermi Bubbles
• A Tale of Tails: Dark Matter Interpretations of the Fermi GeV Excess in Light of Background Model Systematics
• Simplified Dark Matter Models for the Galactic Center Gamma-Ray Excess
• A Renormalizable Model for the Galactic Center Gamma Ray Excess from Dark Matter Annihilation
• Spatial distribution of interstellar gas in the innermost 3 kpc of our Galaxy
• GeV excess in the Milky Way: The Role of Diffuse Galactic gamma ray Emission template
• Cosmic Ray Protons in the Inner Galaxy and the Galactic Center Gamma-Ray Excess
• Hidden On-Shell Mediators for the Galactic Center Gamma-Ray Excess
• WIMPs at the Galactic Center
• Fitting the Galactic Center Gamma-Ray Excess with Cascade Annihilations
• Galactic Center gamma-ray "excess" from an active past of the Galactic Centre?
• Flavored Dark Matter and the Galactic Center Gamma-Ray Excess
• Gamma-ray sky points to radial gradients in cosmic-ray transport
• Higgs portal vector dark matter for $\mathrm{GeV}$ scale $\gamma$-ray excess from galactic center
• Wild at Heart:-The Particle Astrophysics of the Galactic Centre
• Dark Matter Complementarity and the Z${}^{\prime }$ Portal
• Not so Coy Dark Matter explains DAMA (and the Galactic Center excess)
• The Galactic Center GeV Excess from a Series of Leptonic Cosmic-Ray Outbursts
• The Effective Hooperon
• Pseudoscalar Portal Dark Matter
• A weighty interpretation of the Galactic Centre excess
• Hidden Sector Dark Matter Models for the Galactic Center Gamma-Ray Excess
• NMSSM Interpretation of the Galactic Center Excess
• Cosmic Ray Electrons, Positrons and the Synchrotron emission of the Galaxy: consistent analysis and implications
• The Galactic Center Excess from the Bottom Up
• Updated cosmic-ray and radio constraints on light dark matter: Implications for the GeV gamma-ray excess at the Galactic center
• Millisecond pulsar interpretation of the Galactic center gamma-ray excess
• A common solution to the cosmic ray anisotropy and gradient problems
• What Does The PAMELA Antiproton Spectrum Tell Us About Dark Matter?
• Antiproton constraints on the GeV gamma-ray excess: a comprehensive analysis
• Z' Mediated Dark Matter Models for the Galactic Center Gamma-Ray Excess
• Galactic Center Excess in Gamma Rays from Annihilation of Self-Interacting Dark Matter
• Secondary antiprotons as a Galactic Dark Matter probe
• Class of Higgs-portal Dark Matter models in the light of gamma-ray excess from Galactic center
• SUSY Implications from WIMP Annihilation into Scalars at the Galactic Centre
• Secluded WIMPs, QED with massive photons, and the galactic center gamma-ray excess
• Common Origin of 3.55 keV X-Ray Line and Galactic Center Gamma Ray Excess in a Radiative Neutrino Mass Model

Cited by in corpus (49)

• The Fermi Galactic Center GeV Excess and Implications for Dark Matter
• A review of indirect searches for particle dark matter
• The origin of Galactic cosmic rays: challenges to the standard paradigm
• Radial distribution of the diffuse gamma-ray emissivity in the galactic disk
• The Fermi-LAT GeV Excess Traces Stellar Mass in the Galactic Bulge
• The characteristics of the Galactic center excess measured with 11 years of Fermi-LAT data
• Multimessenger constraints on the dark matter interpretation of the Fermi-LAT Galactic center excess
• Strong constraints on thermal relic dark matter from Fermi-LAT observations of the Galactic Center
• 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
• The High-Energy Tail of the Galactic Center Gamma-Ray Excess
• VERITAS Observations of the Galactic Center Region at Multi-TeV Gamma-Ray Energies
• SkyFACT: High-dimensional modeling of gamma-ray emission with adaptive templates and penalized likelihoods
• Improved Cosmic-Ray Injection Models and the Galactic Center Gamma-Ray Excess
• A Search for Dark Matter Annihilation in the Milky Way Halo
• A 750 GeV dark matter messenger at the Galactic Center
• Millisecond pulsar origin of the Galactic center excess and extended gamma-ray emission from Andromeda - a closer look
• Les Houches Lectures on Indirect Detection of Dark Matter
• The Effective J-Factor of the Galactic Center for Velocity-Dependent Dark Matter Annihilation
• Putting Things Back Where They Belong: Tracing Cosmic-Ray Injection with H2
• A Multi-Wavelength Analysis of Annihilating Dark Matter as the Origin of the Gamma-Ray Emission from M31
• 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
• 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
• Prospects for annihilating Dark Matter towards Milky Way's dwarf galaxies by the Cherenkov Telescope Array
• Entering the Era of Dark Matter Astronomy? Near to Long-Term Forecasts in X-Ray and Gamma-Ray Bands
• Pevatron at the Galactic Center: Multi-Wavelength Signatures from Millisecond Pulsars
• MSSM A-funnel and the Galactic Center Excess: Prospects for the LHC and Direct Detection Experiments
• Exploring A Cosmic-Ray Origin of the Multi-wavelength Emission in M31
• Molecular Clouds as the Origin of the Fermi Gamma-Ray GeV-Excess
• Constraints on dark matter annihilation and decay from the large-scale structure of the nearby universe
• Constraining annihilating dark matter by radio data of M33
• Wavelet-Based Techniques for the Gamma-Ray Sky
• Probing the Fermi-LAT GeV excess with gravitational waves
• Dark matter substructure cannot explain properties of the Fermi Galactic Centre excess
• Constraints on dark matter annihilation from the FAST observation of the Coma Berenices dwarf galaxy
• What the Milky Way's Dwarfs tell us about the Galactic Center extended excess
• Signatures of top flavour-changing dark matter
• How to calculate dark matter direct detection exclusion limits that are consistent with gamma rays from annihilation in the Milky Way halo
• The consequence of a new ISRF model of the Milky Way on predictions for diffuse gamma-ray emission
• Searching for Gamma-Ray Emission from Reticulum II by Fermi-LAT
• Diffuse flux of galactic neutrinos and gamma rays
• Investigating the Fermi Large Area Telescope sensitivity of detecting the characteristics of the Galactic center excess
• Connecting the LHC diphoton excess to the Galatic center gamma-ray excess
• A Fermi-LAT Study of Globular Cluster Dynamical Evolution in the Milky Way: Millisecond Pulsars as the Probe
• The Galactic Isotropic $\gamma$-ray Background and Implications for Dark Matter
• Extended Higgs-portal dark matter and the Fermi-LAT Galactic Center Excess