Two years ago, astronomers were confused as the crown of a the supermassive black hole quickly disappeared from view, only to reappear a few months later. New research suggests that this strange episode was caused by a runaway star.
Supermassive black holes are found at the centers of galaxies and, like ordinary black holes, They do not emit any light. That said, they are often surrounded by a rotating gas ring, called an accretion disk, which Causes its surroundings shine rather well. Crownshalos of high-energy particles that generate X-ray light, also betray the presence of supermassive black holes, as this Radiation can be detected from Earth.
In 2018, the crown of a supermassive black hole in the core of 1ES 1927 + 654, a galaxy located about 100 million lightyears away, missing
“We expect changes in luminosity of this magnitude to vary on time scales of many thousands to millions of years.” Erin Kara, co-author of the new study and an assistant professor of physics at MIT, explained in a Press release. “But in this object, we saw [its luminosity drop] at 10,000 over a year, and it even changed by a factor of 100 in eight hours, which is totally unknown and really mind-blowing. “
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Then, over the course of the next few months, the X-ray corona came back into view, glowing as bright as before. Kara said it is “the first time we have seen a crown disappear in the first place, but then it is also rebuilt, and we are seeing this in real time.”
It is important and like the new paper in astrophysical magazine letters he points out, astronomers detected an unusually bright flash shortly before coronal attenuation began. As recorded by the All-Sky Automated Survey for Super-Novae (ASSASN), this flash was approximately 40 times brighter than the galaxy’s normal luminosity. Alerted to the event, astronomers from several other telescopes began to study this active galactic nucleus, observing it at other wavelengths, including optical and ultraviolet.
It was only after this rather intense outburst that the crown of the black hole began to disappear from view. Finally, “it became undetectable, which we have never seen before,Kara said in the MIT press release.
As the new document suggests, this act of disappearance occurred because the black hole was no longer engulfing nearby material, and his food supply, so to speak, had suddenly been cut off. To explain this, the researchers postulated a theory in which a star collided with the black hole.
In this scenario, the rebel star, after being knocked out of its usual orbit by some event, rushed into the black hole and was smashed to pieces by its intense gravitational pull. causing the debris to scatter across the accretion disk. These fast-moving debris then dispersed some of the gas, creating a temporary space between the black hole and the accretion disk.
“Normally we don’t see variations like this in the accumulation of black holes,” said Claudio Ricci, lead author of the study and an astronomer at the Diego Portales University in Santiago, Chile, at NASA. statement. “It was so strange that at first we thought maybe there was something wrong with the data. When we saw that it was real, it was very exciting. But we also had no idea what we were dealing with; No one we spoke to had ever seen anything like this. ”
Finally, this gap was closed and the crown returned to action, according to this theory.
The stray star hypothesis fits the observations very well, but it is not an open and closed case. Astronomers have been unable to explain, for example, why the attenuation appears to have occurred in bursts, rather than gradual decay. The role of black hole magnetic field lines, which can play an important role in generating and supporting high-energy crowns, must also be considered.
“This data set has a lot of puzzles,” said Kara. “But that is exciting, because it means that we are learning something new about the universe. We think the star hypothesis is good, but I also think we are going to analyze this event for a long time. “
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