New research suggests that dark matter plays a crucial role in explaining the gamma ray excess observed at the center of the Milky Way galaxy. The study, led by scientists from the Leibniz Institute for Astrophysics Potsdam and published in the journal Physical Review Letters on October 19, 2025, indicates that the distribution of dark matter in our galaxy differs from previous understandings, potentially confirming that dark matter annihilation contributes to the gamma rays detected.
Researchers utilized high-resolution simulations to model the formation of galaxies resembling the Milky Way under conditions similar to those found in the cosmos. Their findings revealed that dark matter is not distributed in a spherical manner, but is instead flattened and asymmetrical, closely mirroring the arrangement of stars within the galaxy. This new understanding aligns with the theory that the gamma ray excess is a result of dark matter particles colliding and annihilating each other.
Noam Libeskind, an astrophysicist at the Leibniz Institute, highlighted the unexpected findings from the Fermi Space Telescope, which detected an unusually high number of gamma rays at the galactic center. “Astronomers around the world were puzzled, and competing theories started pouring in to explain the so-called ‘gamma ray excess,'” Libeskind stated. Two leading theories emerged: one suggested that ancient millisecond pulsars, which are rapidly spinning neutron stars, could be responsible, while the other pointed to dark matter annihilation as the source.
While both theories have faced scrutiny, the latest research offers compelling evidence for the dark matter hypothesis. The study’s lead author, Moorits Muru, emphasized the significance of the findings, stating, “We analyzed simulations of the Milky Way and its dark matter halo and found that the flattening of this region is sufficient to explain the gamma ray excess as being due to dark matter particles self-annihilating.”
The research underscores the notion that the dark matter halo surrounding the Milky Way is not just a uniform sphere but has a more complex, ellipsoidal shape that could influence the distribution of gamma rays. This revelation adds a new dimension to our understanding of dark matter and its role in the universe.
Scientists have long theorized the existence of a dark matter halo enveloping the Milky Way, a region filled with invisible matter that interacts gravitationally with visible matter. The current study provides insight into the structure of this halo, suggesting that dark matter does not radiate uniformly from the Galactic Center but is organized similarly to stars.
The implications of this research are profound. The results not only bolster the theory of dark matter annihilation but also encourage further investigation into the properties of dark matter particles. As Muru states, “These calculations demonstrate that the hunt for dark matter particles that can self-annihilate should be encouraged and bring us one step closer to understanding the mysterious nature of these particles.”
This study marks a significant advancement in astrophysics, shedding light on the enigmatic nature of dark matter and its potential to explain some of the universe’s most puzzling phenomena. As researchers continue to explore the cosmos, the findings from this study pave the way for new discoveries that could reshape our understanding of the universe.
