The new discovery of astronomers has the potential to double the number of supermassive black holes in the universe. Science for a long time believed that supermassive black holes, as a rule, exist only in the centers of large galaxies like our Milky Way, but the results of the new study confirm the opinion that these objects can exist in the centers of dwarf galaxies.
The study began three years ago when astronomers from the University of Utah (USA) discovered a black hole conveniently located in the center of the ultra compact dwarf galaxy M60-UCD1. However, more recently, the same team of scientists found two more dwarf galaxies with supermassive black holes in their centers, which suggests that such a connection is not as rare as previously predicted. Weight is added to this assumption by the fact that in the visible universe there can be approximately 7 trillion dwarf galaxies, so it is difficult to talk about some ordinary luck. Moreover, a new study has shown that, despite its size, dwarf galaxies are able to contain black holes the size of even larger than what is in the center of our Milky Way.
“It just can not fail to impress. The size of these ultra-compact galaxies is only 0.1 percent of the size of our Milky Way, yet somehow black holes larger than a hole in the center of our galaxy somehow settle in them, “says lead researcher Chris An.
For clarity, we recommend watching the video below, which says how big black holes can be and how much they can possess.
When astronomers began to detect ultra-compact dwarf galaxies in the 90s, they were immediately interested in one very strange detail: the mass of these galaxies did not correlate with the mass of all the stars in them. As part of further research, it was suggested that this extra mass can create supermassive black holes.
“We still do not fully understand how galaxies form and develop. The black holes that exist in their centers can tell us how the galaxies collide and merge, “says An.
Using adaptive optics, which allows more effective observation of galaxies, the researchers measured two ultra-compact galaxies: VUCD3 and M59cO. It was found that the black hole mass of the VUCD3 galaxy is 13 percent of the total mass of the entire galaxy. The black hole of the galaxy M59cO, in turn, accounts for 18 percent of the total mass of its galaxy. Scientists are very surprised, because these indicators were much higher than the parameters typical for the black hole of the Milky Way, whose mass is a little less than 0.1 percent of the total mass of the galaxy. In addition, the results of observations questioned the assumption that the observed objects are not really dwarf galaxies, but are massive star clusters consisting of hundreds of thousands of stars that appeared at the same time. Now scientists believe that these dwarf galaxies once were larger, but at one time they collided with even more massive galaxies that tore them apart by the force of their gravity.
“We know that galaxies sooner or later collide and merge. This is one of the indispensable features of the development of all galaxies in the universe. For example, our Milky Way now, as I say it, also devours nearby dwarf galaxies, and after some time will face a more massive Andromeda galaxy, “- commented one of the researchers, Anil Seth.
“Our general picture of how galaxies form is based on the fact that small galaxies are absorbed into larger ones over time. But the details in this picture were incomplete. The observation of ultracompact galaxies, in turn, allows us to more clearly imagine the direct development of galaxies and to find out what happened to these objects in the past. ”
The conclusion from this can be done this: despite its compact size, dwarf galaxies can hide answers to the biggest questions about the universe.