An international team of astronomers has discovered atypical oscillations of electromagnetic radiation from distant galaxies that are sources of radio waves. Experts call the reason for the passage in front of them of unknown supermassive objects of dark matter, presumably black holes. The article of scientists was published in the Astrophysical Journal, briefly about the study tells the edition of Gizmodo.
In 2009, researchers carried out observations of the galaxy J1415 + 1320 with an active nucleus, which is 3.7 billion light years from Earth. Scientists noticed a short-term increase in the brightness of the radio source, which was then accompanied by a relatively long drop in luminosity. These "dips", lasting 200-500 days, ended with a second increase in brightness. On the chart, such fluctuations looked like "craters".
Similar light fluctuations have been observed for seven other radio sources. Since the researchers had to analyze radio waves from thousands of objects like J1415 + 1320, this makes the observed phenomenon rare.
Such darkening can occur when a gravitational lens passes in front of the radio source. This is the name of any large object that bends the propagation of electromagnetic radiation with its gravitational field. Since the decrease in brightness did not depend on the wavelength, such an object cannot be gas clouds that absorb rays of a certain "color".
According to the researchers, blackouts can occur due to giant black holes, the mass of which is a thousand, millions of times the mass of the Sun. These objects could have remained from the time of the Big Bang and represent dark matter.