For the first time ever, scientists received enigmatic delayed signals from two supermassive black holes that clipped to stars in their vicinity.
In the first case, a black hole of as many as 30 million solar eclipses in a galaxy about 750 million light-years fell away from a star that passed too close to its edge. The light of the event was spotted in April 2019, but six months later a telescope was inside Antarctica caught an extremely high-energy and ghostly particle – a neutrino – it was apparently exhausted during the festival.
A second incident involves a supermassive black hole about 1 million times the solar mass in a galaxy about 700 million light-years away. Observatories spotted it on a star during a luncheon in August 2015 and then fell silent before a sudden eruption of radio wave originated in February 2016 and then again, almost four years later, in July 2019.
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Both events involve a temporary disruption event (TDE), where a supermassive black hole shreds a star into pieces using its colossal gravity – actually an extreme version of how the moon’s gravity increases tides. Earth. Such cosmic events are still not well understood and these two new findings should greatly help astronomers unlock their inner workings.
“Every time we discover a new TDE, there can always be something exciting and unexpected about it,” Jane Dai, who studies high-energy astrophysics at the University of Hong Kong, told WordsSideKick. “So there is a lot of new physics that can be done,” adds Dai, who was not involved in any of the findings.
Researchers classify tidal disturbance events as “transient” phenomena, as they usually flare up over a few days and then fade again. What exactly creates the light in such cases is not yet entirely clear, Assaf Horesh, an astronomer at the Hebrew University of Jerusalem in Israel and co-author of two articles on the new events, told WordsSideKick.
While the supermassive black hole tears his star meal apart, the star becomes “spaghetti” in a long thin ray. This avalanche material revolves around the black hole and is thought to produce a jet of energy as it circles like water flowing down a drain, although other models predict that some of the former star may explode outwards and interact with the surrounding gas and can have dust, the torch, Horesh said.
Given the extreme environment around the black hole, particles can be greatly accelerated in processes such as atomic breakers such as the Large Hadron Collider in Geneva, Switzerland. Neutrinos are small spots that are about 500,000 times lighter than an electron, and since they are neutral (without charge), they do not interact much as they fly through the cosmos.
This allowed a single neutrino to move outward from the first TDE and toward Earth, and eventually into a square-kilometer-long instrument known as the IceCube Neutrino Observatory buried in the Antarctic ice. Researchers have labeled the detection IC191001A and calculated that it has nearly 1 quadillion electron volts of energy, making it one of the most powerful neutrinos IceCube has ever seen, according to one of the new papers.s, published in the journal on February 22 Natural Astronomy.
While physicists have predicted that neutrinos are produced during tidal disruption events, astronomers have never bound a neutrino to a specific TDE, making it a spectacular first. About why it arrived six months after the event itself, “I have no idea,” Horesh said.
A similar mystery surrounding the second study he led, also in Natural Astronomy . In that case, optical light – the kind our eyes see – flares up from a snacking black hole and then disappears, as is usual for these phenomena.
Horesh and his co-authors decided to conduct follow-up studies using the Karl Jansky Very Large Array (VLA) telescope in New Mexico, which detects radio waves. They had not seen anything come out of the black hole for months, and suddenly, six months after the initial event, a bright radio torch arose. Even stranger, VLA data collected nearly four years later again showed a strange eruption of radio energy.
“Someone can make up a story about why we saw something six months later,” Horesh said. “There’s nothing that explains why it should flare up, decay and then flare up again. It’s really interesting.”
He points to the need for new models that can explain these delayed signals. His team speculates that part of the current jet comes out at an odd angle and produces a flare pattern that is sometimes seen and sometimes does not rotate as the accumulator disk. Another possibility is that the star remnants drive shock waves that move slowly through material surrounding the black hole, which later produces energetic emissions, although no one really knows.
As these incidents appear to be lasting longer than originally suspected, Horesh looks forward to detecting more tidal disturbance events that may provide insight into their nature.
Dai, too, is excited about the prospect of opening up ways to study the mysteries of TDEs. “These events are ideal labs to learn about black holes,” she said, giving researchers important clues as to how material around them accumulates and produces rays and torches.
The Vera C. Rubin Observatory in Chile, which is expected to start collecting data this year, could theoretically see hundreds of new TDEs, she added; and other emerging spatial instruments from Europe and China should increase this abundance.
“The future for the field is very bright,” she said.
Originally published on Live Science.