New Simulations Suggest Dark Matter Could Explain the Milky Way’s Central Gamma-Ray Glow

Dark matter may account for the Milky Way’s puzzling central glow

A new study led by Dr. Moorits Muru argues that a complex, non-spherical distribution of dark matter—shaped by the Milky Way’s early mergers and chaotic youth—can naturally reproduce the galaxy’s central gamma-ray excess. The paper appears in the peer-reviewed journal Physical Review Letters and lists co-authors Dr. Noam Libeskind and Dr. Stefan Gottlöber (Leibniz Institute for Astrophysics Potsdam), Prof. Yehuda Hoffman (Hebrew University of Jerusalem), and Prof. Joseph Silk (University of Oxford).

What the team did

Rather than assume a simple, spherical halo of dark matter, Dr. Muru and colleagues used a suite of high-resolution simulations designed to model the Milky Way’s likely formation history. These simulations track mergers, dynamical disturbances and other events that can leave long-lasting imprints on how dark matter is distributed in the galaxy’s inner regions.

Key findings

The simulations produce a more irregular, non-spherical dark-matter morphology at the Galaxy’s center. According to the authors, that more realistic structure can reproduce the observed pattern of gamma rays—commonly known as the Galactic Center Excess—without necessarily invoking additional astrophysical sources such as rapidly spinning neutron stars (millisecond pulsars).

“The Milky Way’s history of collisions and growth leaves clear fingerprints on how dark matter is arranged at its core. When we account for that, the gamma-ray signal looks a lot more like something dark matter could explain,”

Why this matters

For years the origin of the Galactic Center Excess has been debated. Early suggestions included dark-matter particle annihilation, but accumulating observations seemed inconsistent with simple, spherically symmetric dark-matter models. By incorporating the Galaxy’s formation history and realistic dynamical structure, this work reopens the possibility that dark matter contributes to the observed gamma rays.

Caveats and next steps

The authors emphasize that the study does not provide definitive evidence of dark matter detection. Instead, it offers a fresh interpretive framework: either future observations will confirm an observable dark-matter contribution to the gamma-ray signal, or they will reveal previously unknown aspects of the Milky Way’s structure and evolution. Follow-up work will require more detailed modelling, comparisons with gamma-ray maps from instruments such as NASA’s Fermi telescope, and improved constraints on alternative sources like millisecond pulsars.

Bottom line: High-resolution simulations that include the Milky Way’s formation history produce complex dark-matter shapes that can plausibly account for the central gamma-ray excess. This finding motivates targeted observations and refined modelling to distinguish between a dark-matter signature and other astrophysical explanations.