New Analysis Pushes Milky Way Gamma-Ray Excess Toward Dark Matter, Requiring 35,000-200,000 Faint Sources
Updated
Updated · The Brighter Side of News · Jun 19
New Analysis Pushes Milky Way Gamma-Ray Excess Toward Dark Matter, Requiring 35,000-200,000 Faint Sources
2 articles · Updated · The Brighter Side of News · Jun 19
Summary
A machine-learning reanalysis of the Milky Way’s Galactic Center Excess found any point-source explanation would require extremely dim emitters, making the gamma-ray glow look far smoother than earlier studies suggested.
Using 812 weeks of Fermi data and photon energies from 2 to 20 GeV, the team combined spectral and spatial information that prior statistical work largely omitted.
The inferred source population jumped to a median of about 200,000 objects in the Galactic Center region, with even the 90% upper quantile still around 35,000—far above earlier estimates near 200 or a few thousand.
A separate test could exclude only 3% of the map as inconsistent with smooth Poisson-like emission at 95% confidence, weakening a major argument that the excess must come from unresolved pulsars.
The authors said this is not a dark matter detection, because diffuse background modeling still shifts source estimates from roughly 10,000 to 100,000, but it keeps dark matter firmly in contention.