In 2017, astronomers discovered a phenomenon known askilonova‘ : Merger of two neutron stars accompanied by powerful gamma-ray bursts. Three and a half years later, astrophysicists have discovered mysterious X-rays that they believe may be the first evidence of a “post-kilonova glow,” according to a new research paper published. Astrophysicists may be the first A note of the matter in black hole formation after the merger fell.
as inform us before, DISCOVER LIGO by gravitational waves laser interferometry. This method uses high-powered lasers to measure small changes in the distance between two objects that are miles apart. (LIGO has detectors in Hanford, Washington, and in Livingston, Louisiana. A third detector in Italy, known as Advanced VIRGO, was commissioned in 2016.) With three detectors, scientists can pinpoint the source of the chirping of the night sky.
Discover the second round of LIGO from November 30, 2016 to August 25, 2017, along with seven binary black hole mergers. Binary fusion between neutron stars Once gamma ray burst and signals in the rest of the electromagnetic spectrum. The event is now known as GW170817. Those signals included indications of the presence of heavy elements – particularly gold, platinum and uranium – that resulted from the impact. Most of the lighter elements form in the stifling explosions of massive stars known as supernovae, but astronomers have long assumed that the heavier elements could come from kilonovae that form when two neutron stars collide.
Kilonova’s discovery in 2017 provided evidence that these astronomers were right. The recording of such a celestial event was unprecedented and officially marked the beginning of a new era in the so-called “Multiple message in astronomy. “
Since then, astronomers have been searching for a matching optical signature when LIGO/VIRGO picks up a gravitational wave signal from neutron star mergers or potential mergers between neutron stars and a black hole. The assumption was that black holes and black hole mergers would not produce a light signature, so there was no point in looking for a signature – until 2020. Then astronomers discovered first guide for such a phenomenon. Astronomers made the discovery by combining gravitational wave data with data collected during an automated sky survey.
But Kilonova’s 2017 film remains unique, according to Abrajita Hajela, lead author of the new paper and a graduate student at Northwestern University. hopscotch Call Kilonova “The only event of its kind” and “a treasure chest with several initial notes in our field”. Together with other astronomers from Northwestern University and the University of California, Berkeley, he has been monitoring the evolution of GW170817 since its initial discovery by LIGO/Virgo using a space-based spacecraft. Chandra X-ray Observatory.
Chandra first detected X-ray and radio emissions from GW170817 two weeks after the merger, which lasted 900 days. But those initial X-rays, propelled by a jet of near-light-speed fusion, began fading out in early 2018. However, from March 2020 through the end of this year, the sharp drop in brightness stopped and the X-ray emission became fairly constant in terms of brightness.
To solve this mystery, Hajela and her team collected additional observational data using both Chandra and Very Large Array (VLA) in December 2020, 3.5 years after the merger. It was Hajela who woke up at 4 a.m. to notice a surprisingly strong and bright X-ray emission – four times higher than would have been expected at the time if the emissions were driven only by the aircraft. (The VLA did not detect any radio emissions.) These new emissions remained at a constant level for 700 days.
This means that a completely different source of X-rays must be the source of energy for them. One possible explanation is that the expanding debris from the merger created a sonic boom and jets of shock waves. In this case, the merging neutron stars cannot instantly collapse into a black hole. Instead, the stars are spinning fast for a second. This rapid spin would have countered the gravitational collapse briefly enough to create a fast trajectory for the Kilonova’s heavy projectiles, which were the impetus behind the shock wave. As these heavy projectiles slowed down over time, their kinetic energy was converted into heat through impacts.
“You will fall in. It is finished.”
“If merging neutron stars collapsed directly into a black hole without an intermediate phase, it would be very difficult to explain the excess X-rays we see now because there would be no solid surface for things to bounce off at higher altitude velocities, um.” to create those auroras. Co-author Raffaella Margotti said: from the University of California at Berkeley. “You’ll fall in. Finished. The real reason I’m scientifically excited is that we might see more of the plane. We can finally get information about the new compact object.”
Brian Metzger of Columbia University has proposed an alternative scenario: X-ray emission could be released by material falling into the aurora formed during fusion. This is also the first scientific finding, Hagel said, because this kind of long-term buildup hasn’t been observed before.
More feedback is planned from now on, and this data will help solve the problem. If X-rays and radio emissions brighten over the next few months or years, they will confirm the Kilonova Aurora scenario. If the X-ray emissions declined sharply or remained constant, with no accompanying radio emissions, this would confirm the black hole accretion scenario.
Regardless, “this would be the first time we’d see a kilonova auroras or the first time we’d see matter falling into a black hole after a neutron star merger.” Co-author Joe Bright said:Postdoc at the University of California, Berkeley. “None of the results will be very exciting.”
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