A recently discovered tiny galaxy orbiting the milky way is emitting electromagnetic radiation in the form of gamma rays, according to astronomers, who believe that the finding may either be a false alarm or the proof that dark matter exists and permeates the universe. If the existence is confirmed, it would imply that majority of the universe is in the form of a heavy elementary particle which is 20 to 100 times as heavy as a proton and which has been clumping like fog in space ever since the event of Big Bang.
But while the gamma-ray signal is “tantalizing,” in the words of Alex Geringer-Sameth of Carnegie Mellon University and colleagues from Brown and Cambridge Universities, “it would be premature to conclude it has a dark matter origin.” Their analysis appears in a paper submitted to the journal Physical Review Letters.
The group made use of data from NASA’s Fermi Large Area Telescope that orbits the Earth for search gamma rays from an accumulation of stars known as Reticulum-2, in the southern constellation of the same name.
It is one of the difficult-to-find galaxies called dwarf galaxies that have less than a hundred stars and are only a billionth as bright and a millionth as large as the milky way. Dwarf galaxies are the choice of astronomers for finding dark matter since these galaxies contain little atomic matter. That mysterious stuff has led scientists on a merry chase ever since Fritz Zwicky in the 1930s and Vera Rubin and her colleagues in the 1970s discerned that galaxies move under the gravitational influence of massive clouds of invisible matter.
Cosmologists have agreed that this matter forms 80% off the matter in the universe and is not the ordinary atomic matter that stars, planet and living beings are made out of, nor anything else predicted by Standard Model which has dominance over particle physics today.