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Study Reports 20 GeV Gamma-Ray Halo at Milky Way’s Center Consistent With Dark Matter

Independent teams must confirm the signal in cleaner targets to establish a dark matter origin.

Overview

  • University of Tokyo astronomer Tomonori Totani analyzed about 15 years of NASA Fermi data and identified a halo-shaped gamma-ray excess around the Galactic center that peaks near 20 GeV.
  • The measured spectrum and morphology align with predictions for WIMP annihilation, suggesting particles roughly 500 times the proton mass and an annihilation rate within standard models.
  • The findings, published in the Journal of Cosmology and Astroparticle Physics, are presented by the author as a strong indication rather than definitive proof.
  • Independent experts caution that complex backgrounds and analysis choices in Fermi data can mimic such signals, noting unresolved debates over previous Galactic-center excess claims and the possibility of astrophysical sources or artifacts.
  • Key checks now include reanalyses by other groups, searches for the same 20 GeV feature in dark-matter–dominated dwarf galaxies, continued Fermi monitoring, and follow-up with CTAO and complementary underground detectors.