(ORDO NEWS) — In the life cycles of all supermassive black holes (SMBHs) located in the centers of galaxies, there are probably periods when these black holes absorb matter from their immediate vicinity. But that’s where the similarities end. This is the conclusion reached by British and Dutch astronomers, observing one well-studied area of the sky with a supersensitive radio telescope.
Astronomers have been studying active galaxies since the 1950s. At the centers of active galaxies there are SMBHs that absorb matter. During these active phases, these objects often emit extremely powerful radio, infrared (IR), ultraviolet (UV) and X-rays.
In the new study, astronomers turned their attention to all active galaxies located within the boundaries of a well-studied region of the sky called GOODS-North, lying in the direction of the constellation Ursa Major. Until now, this region of outer space has been studied mainly using space telescopes operating in optical, infrared and UV light. To these data in the new work, the researchers added data from observations carried out using a network of sensitive radio telescopes, including the British observatory e-MERLIN national facility and the European VLBI Network (EVN).
Through systematic research, astronomers have identified three main points. First, it turned out that the nuclei of galaxies of different types exhibit different activities. Some black holes are extremely voracious, consuming as much material as possible; other SMBHs chew their food more slowly, while some black holes “starve” at all.
Second, sometimes the accretion phase coincides with the formation of new stars, and sometimes it does not. If star formation continues in the galaxy, the activity in the core is more difficult to detect.
Third, as a result of accretion processes occurring in the core, radio jets may or may not be emitted – regardless of the speed at which the black hole absorbs its “food”.
According to lead author Jack Radcliffe of the University of Pretoria, South Africa, the observations also show that radio telescopes are optimal for studying the “feeding habits” of black holes in the distant Universe. “This is good news, as the completion of the SKA radio telescopes is just around the corner, and they will allow us to look deeper into the universe and receive new information about the features of its design.”
Two publications on the results of this study were published in the journal Astronomy & Astrophysics.
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