A team of researchers took a closer look at the brightest gamma-ray burst in at least 10,000 years and discovered a unique emission line that they believe could reveal some of the extreme physics at the heart of the burst.
The team’s research was published this week in science, Ask about the emission line that appears about 280 seconds after the gamma-ray burst begins.
“When I first saw this signal, I got goosebumps,” Maria Edwig Ravasio, a researcher at Radboud University in the Netherlands and lead author of the study, said in a note released by NASA. stated in a press release. “Our subsequent analysis showed that this was the first high-confidence emission line seen in 50 years of gamma burst research.”
What was this gamma ray burst?
Gamma-ray bursts are particularly massive space explosions thought to be caused by the glorious death of a distant star. Its full name is GRB 221009A, but it’s more commonly known as “BOAT,” or “brightest ever.” It’s not true, but it’s definitely the brightest on record.
The burst contained so much information about the star’s collapse that it was transmitted so well that it temporarily overwhelmed most space-based observatories in X-rays and gamma rays. But nearly two years after the incident, researchers are still learning new information about the ship.
“While some previous studies reported possible evidence of other gamma burst absorption and emission features, subsequent review showed that all of these may just be statistical fluctuations. What we see on board is different,” says INAF-Brela Observatory researcher , Om Sharan Salafia, co-author of the paper, said in the same press release. “We have determined that the chance that this feature is just a noise fluctuation is less than one in 500 million.”
A brief history of ships
The ship was first discovered in October 2022 by the National Science Foundation’s NOIRLab telescope Gemini South. He was soon overwhelmed by the light of the ship.
This incident was confirmed as a “ship” incident in March 2023. The brightest bursts of X-ray and gamma-ray energy.” The ship was determined to be a once-in-a-million-year event. A research team publishes X-ray observations of the explosion Astrophysical Journal Communications.
That June, another team analyzed the structure of BOAT’s gamma-ray injector. Astronomers believe the structure of the burst could provide a blueprint for understanding gamma-ray bursts, other bursts of energy ejected from collapsing stars.
Researchers published a more complete analysis of BOAT’s gamma-ray energy output in November 2023. Ultimately, the team discovered more than 140 gamma rays in events exceeding 3 teraelectronvolts. One researcher told Gizmodo that the discovery “challenges the standard model of gamma burst afterglows.”
What did the researchers find?
The emission line discovered by the research team lasted about 40 seconds and had a peak energy of about 12 million electron volts. The team believes this is caused by collisions between electrons and positrons (their antimatter counterparts).
“When electrons and positrons collide, they annihilate,” study co-author Gor Oganesyan, a researcher at the Gran Sasso Institute of Science and the Gran Sasso National Laboratory, said in the same press release. “Because we are studying Jets in which matter moves at close to the speed of light, so this emission is extremely blue-shifted and pushed to higher energies.”
According to the NASA article, in order to obtain the peak energy the team observed, the electron-positron pair must be traveling towards us at 99.9% of the speed of light. The extreme explosiveness of BOAT is already well known, but new research puts this dynamic into perspective.
What to do with the ship now?
Scientists are still carefully studying the explosive consequences of the 2022 explosion. Just this past April, a team used the Webb Space Telescope to study the origin of the burst and found that it was caused by a supernova: the glorious, explosive death of a star. The team found no signs of heavy elements on board, leaving the origin of these elements in the universe an open question.
Further study of Ship’s sediments and continued observations of other gamma-ray sources could provide clues to these events, some of which are among the most intense in our universe.
