The supermassive black hole in the center of the Galaxy 1S 1927+654, imagined here, houses not only a just hidden jet (at the top right), but perhaps also a white dwarf orbit (at the bottom right). Credit: Aurore Simonnet/Sonoma State University
In 2018, a distant black hole launched a fit. The 1.4 million solar mass hole in the center of the Galaxy 1S 1927+654 at about 270 million light years away suddenly began to vomit radiation, flaking in the perspective, ultraviolet and X -ray light.
Therefore, astronomers observed while the so-called X-ray crown of high energy particles closed in the black hole folk-lies to reform slowly over time. The most probable cause of this strange behavior was a rebellious star that wandered too close, just to be made to pieces and consumed by the black hole in what astronomers call an event of interruption of the tides or TDE.
Since then, the researchers have kept an eye on this goal. And their vigilance gave its fruits in two great ways, the astronomers announced yesterday at the 245th meeting of the American Astronomical Society of National Harbor, Maryland.
A jet is born
For a while after the TDE, 1S 1927+654 was silent, in particular to the radio wavelengths. But then, in 2023, the researchers saw its production of X -rays start increasing. This pushed the astronomer of the county of Baltimore Eileen Meyer and his team to check -in on the galaxy radio emission. They found that the black hole was also inflaming to that wavelength. At his peak, he said in his presentation, the Galaxy radio emission has increased more than 60 times his previous level and remained high.
“Normally, this level of radio emission would tell us that there are jets,” he said-a declaration corroborated by a following year of high resolution radio images focused on the supermassive black hole and show smaller details of a light year. They show two hot gas spots that move away from the supermassive black hole about 33 percent of the speed of light.
“This has no precedents. We have never had this success. We never looked at a black hole and saw him go from a silent radio to a suddenly strong radio, “said Meyer. In essence, his team witnessed the birth of Jets from a supermassive black hole, in real time.
Meyer is the main author of a document that outlines the discovery, published on January 13 in The letters of Astrophysics magazine.
Rapid development
Only 10 percent of the supermassichi black holes is shooting on radio, generally covering thousands of light years or more and reaching the intergalactic space. But while we have seen these jets evolve over time, we have never actively seen anything.
In addition, astronomers have long thought that the formation of jets requires a long time: “We expect the temporal stairs to turn on and turn off are long – and certainly longer than, let’s say, a human life,” Meyer said. “Or at least, this was a kind of naive expectation previously.”
The team thinks in this case, the jets probably formed due to the TDE observed in 2018. And perhaps this indicates that 1S 1927+654 is a type of “reduced” situation classified as a compact symmetrical object, which lights up for for Thousands of years instead of millions and are activated not by a huge influx of material, but by a single TDE.
Following X -ray flash.
Getti’s formation is not the only reason why 1s 1927+654 is now in the spotlight. After Meyer’s speech he was Megan Masterson, a student graduated from the Mit and the main author of an article now accepted for publication in Nature and available on Arxiv Preprint server.
Masterson focused on X -rays seen from 1S 1927+654, which at the beginning showed the random variations generally provided for by the feeding of black holes after the 2018 event. But starting from 2022, the emission of rays X changed, showing periodic oscillations while X -rays light up and faded with a regular period of about 10 minutes. These short -term oscillations, he said, are extremely difficult to detect and 1s 1927+654 is one of the only handful of supermassichi black holes in which they were seen.
So something has changed. The X -ray period began to drastically reduce: in 2022, the period was 18 minutes. In 2024, they were seven minutes and it seems to have stabilized there.
Two possibilities
What could be regular “flicker” x -ray so close to a supermassive black hole? And why is the period reducing itself? There are two possibilities, Masterson said. One is that the flicker are linked to the newly trained jet found by Meyer’s team. If the X -rays come from the base of the jet, the oscillations in the jet itself or the variations of the physical dimension of the base of the jet could explain the period of change.
But there is an even more intriguing possibility. “The orbits naturally give you this beautiful periodic behavior. And … there is a really simple way to change the period when you are in orbit, and this is to change the actual distance of that orbit, “he said.
Therefore, some objects may always be reversed to the supermassive black hole-in a phenomenon that has been seen before, although others of these orbits have periods of hours or days, not a few minutes. In the case of 1S 1927+654, a period of seven minutes translates into an orbit a few million miles from the horizon of the event, the point of no return, “on the edge of that growth disc”, around the hole Black said.
The orbit “cannot be a [smaller] Black Hole “, because a black hole in stellar mass in so nearby would lose energy quickly by emitting gravitational waves and dives into the largest black hole. It would not do it Maintain orbit for years. “Instead … we need an additional source of energy, in order to keep this object outside the horizon of the events of the black hole,” he said.
That’s why his team thinks that the orbit is a white dwarf of 0.1-1-just-the overheated and compact residue of a star similar to the sun. A white dwarf would also lose the angular moment through gravitational waves, but also has an additional source of energy. Slowly losing its external material with the supermassive black hole in a process called mass transfer, a white dwarf could I earn Energy and angular moment, keeping it in orbit rather than spiral.
Why a white dwarf specifically, and not just a few star? “The white dwarfs are small and compact, they are very difficult to destroy, so they can be very close to a black hole,” explained the astronomer of Mit Erin Kara, co -author on paper, in a press release.
Waiting to hear
For now, it is not clear which scenario is correct. But when the antenna of the ESA laser interferometer (Lisa) interferometer is launched in the 1920s, it will be the sensitivity to detect gravitational waves with frequencies in the range of what astronomers foresee from 1S 1927+654, if there is It is a white dwarf orbit. And if Lisa does not “listen to” nothing, then the most probable cause of the trembling X -rays is the jet, which would not produce gravitational waves.
For now, astronomers will continue to look closely at 1s 1927+654. “The only thing I learned with this source is never to stop looking at it because it will probably teach us something new,” Masterson said.
