Scientists at the Harvard and Smithsonian Center for Astrophysics in the United States have carried out detailed simulations of mysterious dark matter to reveal its alleged properties. Universe Today reports on unexpected results.
The researchers hypothesized that dark matter is composed of weakly interacting massive particles (WIMPs) with a mass about a hundred times that of a proton. In the model, such dark matter formed halos around galaxies. However, it turned out that halos can have completely different masses: from the mass of the planet to the masses of galactic clusters. They have a characteristic texture, becoming denser from the edges towards the center.
Small-scale halos are too small to be detected by their gravitational effect on light. However, one hypothesis is that when dark matter particles collide, they emit gamma rays. Most of the gamma radiation generated by dark matter will come from a small halo. Since the scale of the halo can affect the energy spectrum of gamma rays, this model allows specific predictions of the excess gamma rays that are observed in the center of the Milky Way.
One of the phenomena that previously could not be explained without the involvement of dark matter was the distribution of gamma radiation in the Galaxy. So, in the center of the Milky Way, there is a “thickening” of gamma rays compared to the outskirts. However, another group of scientists concluded that a large number of pulsars near the center of the Milky Way can create the appearance of smoothly distributed radiation, making it look like the picture that is expected from dark matter. The exact cause of the phenomenon is still unknown.
