Study Detects Potential Dark Matter Signal in Gamma Rays

A new study analyzing 15 years of data from NASA's Fermi Gamma-ray Space Telescope has identified gamma-ray emissions that researchers say could represent the first direct evidence of dark matter, the invisible substance believed to constitute about 27 percent of the universe.

The research, led by astrophysicist Tomonori Totani of the University of Tokyo, focused on a halo-shaped region surrounding the Milky Way's center. Totani detected a pattern of high-energy gamma rays, peaking at around 20 gigaelectronvolts, that aligns with the predicted shape and distribution of the galaxy's dark matter halo. These emissions, described as extending in a spherical structure, appear to match signals expected from the annihilation of weakly interacting massive particles, or WIMPs, one of the leading candidates for dark matter composition. The findings were published Tuesday in the Journal of Cosmology and Astroparticle Physics.

Totani's analysis isolated the gamma rays by subtracting known sources of emissions, such as cosmic rays, stars, and the Fermi bubbles, from the telescope's observations. The remaining signal formed a faint, halo-like glow that, according to the study, does not easily...