A star ended up too close to a black hole; so much so that it ended up being vaporized by it and, thanks to this event, scientists have managed to detect a high-energy neutrino, known as ghost particles, which was launched into space during this time.
We call them ghost particles because, at the moment, their origin is unknown. They have no electrical charge, they do not interact with normal matter, they travel almost at the speed of light, and they have very small masses. That is why this finding is so important: it brings us a little closer to discovering the precise moment in which the most energetic particles in the universe are born, the high-energy cosmic neutrinos, which we know leave the Sun’s nucleus in large quantities and in the Earth we can create them in nuclear reactors and particle accelerators.
The work, which included researchers from more than two dozen institutions, including New York University and Germany’s DESY research center, focused on neutrinos, subatomic particles that are produced on Earth only in powerful accelerators.
“The origin of high-energy cosmic neutrinos is unknown, mainly because they are notoriously difficult to pin down,” comments astrophysicist Sjoert van Velzen of the University of Leiden in the Netherlands. “This result would be only the second time that high-energy neutrinos have been traced back to their origin.”
It is not easy to detect the death of a star through a black hole. Fortunately, it’s an event we’ve seen many times before: in essence, a wandering star gets close enough to a black hole to be trapped by its gravity, and the black hole’s tidal force pulls on the star so hard that suffers spaghetti and it ends up breaking. It is what is known in astronomy as a tidal disruption event (TDE, tidal disruption event)
Would the TDEs be responsible for producing these ‘ghost particles’?
This is where the neutrino telescope located at the Amundsen-Scott South Pole station comes in. IceCube. Every now and then a neutrino is able to interact with ice and create a flash of light, something that can be traced. Thus, based on characteristics such as how the light spreads and how bright it is, scientists can determine how energetic the neutrino is and the direction from which it is coming.
Analyzing IC191001A , an IceCube detection that occurred on October 1, 2019 with one of the highest-energy neutrinos detected so far, crashing into the Antarctic ice with an energy of more than 100 teraelectronvolts , they found that there was only one 0.2% probability that it was not associated with AT 2019dsg, another previous event observed on Earth in April 2019 emitted by a supermassive black hole that recorded 30 million times the mass of the Sun from about 750 million light years away. distance.
“This suggests that these star crushing events are powerful enough to accelerate high-energy particles,” the authors explain in the journal Nature Astronomy . “Discovering neutrinos associated with TDE is a breakthrough in understanding the origin of the high-energy astrophysical neutrinos identified by the IceCube detector at the South Pole whose sources have so far been elusive. The neutrino-TDE coincidence also sheds light on a decades-old problem: the origin of ultra-high-energy cosmic rays. “
“Without detecting the tidal disruption event, the neutrino would be just one of many. And without the neutrino, observing the tidal disruption event would be just one of many. Only through combination could we find the accelerator and learn something new about internal processes, “clarifies astrophysicist Marek Kowalski from DESY and Humboldt University in Germany.
Referencia: A tidal disruption event coincident with a high-energy neutrino, Nature Astronomy (2021). DOI: 10.1038/s41550-020-01295-8 , www.nature.com/articles/10.1038/s41550-020-01295-8
