Physicists from Italy and Sweden have confirmed that dark matter is the most likely source of the mysterious excess of gamma radiation from the center of the Milky Way. The preprint of the article with the research results is published in the arXiv.org repository.
Scientists analyzed the data obtained with the Fermi Space Telescope and compared it with astronomical anomalies recorded by detectors and spectrometers on the International Space Station (ISS). Since 2009, an excess of photons with energies equal to or exceeding one gigaelectronvolt, emanating from the center of the galaxy, began to be detected. Previously, researchers tried to explain the anomaly by clusters of faint pulsars, as well as the existence of dark matter.
The new results showed that the excess gamma rays mostly come from the center of the galaxy, which is expected if the source is unknown particles that make up dark matter. If gamma radiation was generated by the interaction between cosmic rays and atoms, a dependence of the spatial distribution of photons on their energy would be observed, but such dependence was not found.
Physicists have also shown that the dark matter hypothesis is not refuted by other anomalies recorded by the ISS instruments. These include the excess of positrons and the absence of high-energy photons from dwarf galaxies close to the Milky Way.