The Characterization of the Gamma-Ray Signal from the Central Milky Way: A Compelling Case for Annihilating Dark Matter
read the original abstract
Past studies have identified a spatially extended excess of $\sim$1-3 GeV gamma rays from the region surrounding the Galactic Center, consistent with the emission expected from annihilating dark matter. We revisit and scrutinize this signal with the intention of further constraining its characteristics and origin. By applying cuts to the \textit{Fermi} event parameter CTBCORE, we suppress the tails of the point spread function and generate high resolution gamma-ray maps, enabling us to more easily separate the various gamma-ray components. Within these maps, we find the GeV excess to be robust and highly statistically significant, with a spectrum, angular distribution, and overall normalization that is in good agreement with that predicted by simple annihilating dark matter models. For example, the signal is very well fit by a 36-51 GeV dark matter particle annihilating to $b\bar{b}$ with an annihilation cross section of $\sigma v = (1-3)\times 10^{-26}$ cm$^3$/s (normalized to a local dark matter density of 0.4 GeV/cm$^3$). Furthermore, we confirm that the angular distribution of the excess is approximately spherically symmetric and centered around the dynamical center of the Milky Way (within $\sim$$0.05^{\circ}$ of Sgr A$^*$), showing no sign of elongation along the Galactic Plane. The signal is observed to extend to at least $\simeq10^{\circ}$ from the Galactic Center, disfavoring the possibility that this emission originates from millisecond pulsars.
This paper has not been read by Pith yet.
Forward citations
Cited by 9 Pith papers
-
WIMP-like Dark Matter Without Thermalization At Freeze-Out
Hidden-sector dark matter achieves standard thermal relic abundance via early decoupling with temperature-matched freeze-out, enabling WIMP-like cross sections without late-time thermalization.
-
Probing Cosmic-Ray-Boosted and Supernova-Sourced Sub-GeV Dark Matter with Paleo-Detectors
Paleo-detectors can achieve high sensitivity to sub-GeV dark matter boosted by cosmic rays and supernovae, covering previously inaccessible parameter space with orders of magnitude better reach than current experiments.
-
High-dimensional inference for the $\gamma$-ray sky with differentiable programming
A differentiable forward model and likelihood enable probabilistic inference over many spatial morphologies for the Galactic Center gamma-ray Excess using variational methods on GPUs.
-
A Precise Measurement of the Fermi-LAT Galactic Center Excess Morphology and Spectrum
Refined Fermi-LAT analysis finds the Galactic Center Excess has a centrally concentrated spherical morphology consistent with generalized Navarro-Frenk-White inner slope ~1.15, significant across interstellar emission...
-
A Comprehensive Study of WIMP Models Explaining the Fermi-LAT Galactic Center Excess
WIMP models for the Galactic Center Excess survive only in finely tuned resonant funnels with portal couplings around 10^-4, with leptophilic vectors and pseudoscalar portals remaining most viable after current bounds.
-
Planck 2018 results. VI. Cosmological parameters
Final Planck CMB data confirms the flat 6-parameter ΛCDM model with Ω_c h² = 0.120 ± 0.001, Ω_b h² = 0.0224 ± 0.0001, n_s = 0.965 ± 0.004, τ = 0.054 ± 0.007, H_0 = 67.4 ± 0.5 km/s/Mpc, and no strong evidence for extensions.
-
Testing Viability of Benchmark Dark Matter Models for the Galactic Center Excess
Updated constraints on two simplified dark matter models for the Galactic Center Excess leave unconstrained parameter space after applying recent multi-experiment data.
-
Cosmological searches for the neutrino mass scale and mass ordering
Thesis summarizing an upper limit of 0.12 eV on the neutrino mass sum, bias calibration via CMB lensing cross-correlations, and tighter limits plus stronger normal-ordering preference in non-phantom dynamical dark ene...
-
Electroweak Doublet Dark Matter for a Galactic Halo Gamma-Ray Excess
Electroweak doublet dark matter with Higgs-portal interactions accounts for the Galactic halo gamma-ray excess via gauge boson annihilation and allows inelastic scattering with ~100 keV splitting.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.