For the first time, astronomers believe they have discovered two pairs of merging dwarf galaxies. Each pair represents a duo of black holes that will soon collide. The observations may reveal new details about the early formation of large galaxies like the Milky Way and the supermassive black holes lurking at their centers.
Despite their relatively small size, dwarf galaxies pack a big scientific punch. Dwarf galaxies were thought to be the most abundant type of galaxy during the first few hundred million years after the Big Bang. must have been the progenitor of the larger objects we see today. However, it is an open question whether these cosmic building blocks also contain sizable central black holes. But now astronomers believe they have found a clue. They found evidence of massive black holes feeding on gas and dust in what appear to be two colliding pairs of dwarf galaxies. The team described his two candidate systems in a paper published last month. astrophysics journal.
Examples of dwarf galaxy mergers have been discovered before, some of which even showed signs of a black hole in one of the galaxies, said lead author of the study, PhD in astronomy at the University of Alabama. Course student Marko Mićić said: But no one has ever seen double black holes in colliding dwarfs. Each of his two systems that Micich and his colleagues studied are “probably perfect analogues of events that occurred in the very early universe,” he says.
And perhaps best of all, one of the two pairs is cosmically relatively close, just 760 million light-years away, making it a good target for more detailed observations. Dwarf galaxies are not easy to observe because they contain only the stars and missing masses of typical Milky Way-sized galaxies. Nor do they necessarily behave in the same way as larger galaxies.
“Dwarf galaxies usually look like small train wrecks. “They are very cool labs.”
To identify two interesting mergers, Micich and his colleagues used NASA’s Chandra X-ray Observatory, the space agency’s Wide Field Infrared Explorer (WISE) Space Telescope, now called NEOWISE, and Canada’s 3 We used archived data from two instruments. The French-Hawaii Telescope (CFHT) in Hawaii.
Black holes themselves are invisible, but when they engulf the matter around them, they can set off some of the brightest fireworks in the universe. Falling matter swirls around them at nearly the speed of light, heating up to a powerful glow that illuminates the universe with multiple wavelengths of light. Chandra saw its glow in the X-ray portion of the electromagnetic spectrum, but Wise glimpsed it in the infrared. suggests that it exists in each of the two ‘active’ black holes, but there is no confirmation. CFHT provided images of the dwarf galaxy itself, revealing star-like evidence of likely intergalactic collisions and optically bright clumps aligned with the X-ray and infrared glow.
The closer candidate merger appears to be in the late stages of merger, with one dwarf galaxy accompanied by an ornate, massive tail of stellar remnants, possibly shredded remnants of the other. Its tail inspired scientists to invent a system named Mirabilis. logigesia is great, A species of hummingbird that boasts two long, narrow tail plumes that terminate in ping-pong oars of its wings.
The second candidate is even more distant (about 3.2 billion light years) and is in the early stages of the merger process. Because the two dwarf galaxies are more widely separated in space and are largely intact, scientists have named them both, named after characters in Marcel Proust’s novel, one named Elstil and another named after him. I summoned two Venteuil. in search of lost timeThe merger will likely take hundreds of millions of years to complete, Micich said.
Mićić and his colleagues have made two pairs of additional observations, especially in radio and ultraviolet light. Some of these follow-up observations point to a small but important lingering uncertainty about whether the galaxy is indeed a dwarf rather than the twisted remnants of a giant galaxy torn apart by the gravitational pull of the galaxy cluster in which it inhabits. may eliminate Further scrutiny strengthens the case that the core’s bright glow is actually coming from a greedy black hole, and may even help calculate the masses of these hidden giants.
If successful, the discovery could be a key element in solving the larger cosmic puzzle of how galaxies and black holes have emerged and co-evolved in the history of the universe. says Stierwalt. “This will be important evidence that some of the processes that occur in large galaxy mergers also occur in dwarf galaxy mergers,” she says.
