NASA’s Fermi Gamma-ray Space Telescope has potentially captured the first direct evidence of dark matter, as gamma rays from the center of the Milky Way appear to bear its signature, according to research published Wednesday in the Journal of Cosmology and Astroparticle Physics.
Tomonori Totani of the University of Tokyo said the findings could represent a crucial breakthrough in the long-running search for dark matter – a hypothetical, invisible form of matter that does not interact with electromagnetic radiation.
The concept dates back to the early 1930s, when Swiss astronomer Fritz Zwicky noticed that galaxies were moving faster than their visible mass could explain, suggesting the presence of an unseen structure holding them together.
Until now, dark matter has only been detected indirectly through its gravitational effects. Scientists say it cannot be observed directly because dark matter particles do not interact with electromagnetic forces and therefore do not absorb, reflect or emit light.
Using the latest data from NASA’s Fermi telescope, Totani believes he has detected gamma rays predicted by the annihilation of theoretical dark matter particles.
"We detected gamma rays with a photon energy of 20 gigaelectronvolts ... extending in a halo-like structure toward the center of the Milky Way galaxy," he said in a statement released by the university.
He said the gamma-ray component "closely matches the shape expected from the dark matter halo."
"If this is correct, to the extent of my knowledge, it would mark the first time humanity has ‘seen’ dark matter. And it turns out that dark matter is a new particle not included in the current standard model of particle physics," Totani said.
He added that such a finding "signifies a major development" in astronomy and physics.
