麻豆淫院

An international team of astronomers has discovered the first tidal disruption event (TDE) producing bright radio emission outside the center of a galaxy. The findings are in The Astrophysical Journal Letters.

The event, designated AT 2024tvd, revealed the fastest-evolving radio emission ever observed from a black-hole-driven stellar disruption. The team was led by Dr. Itai Sfaradi and Prof. Raffaella Margutti of the University of California, Berkeley, with the participation of researchers from around the world, including Prof. Assaf Horesh from the Racah Institute of 麻豆淫院ics at the Hebrew University of Jerusalem.

"This is truly extraordinary," said Dr. Sfaradi, lead author of the study. "Never before have we seen such bright radio emission from a black hole tearing apart a star, away from a galaxy's center, and evolving this fast. It changes how we think about black holes and their behavior."

Dr. Sfaradi, who led the research, is a former graduate student of Prof. Horesh. "This is one of the fascinating discoveries I've been part of," said Prof. Horesh. "The fact that it was led by my former student, Itai, makes it even more meaningful. It's another scientific achievement that places Israel at the forefront of international astrophysics."

A black hole far from home

Tidal disruption events occur when a star ventures too close to a massive black hole and is torn apart by its immense gravity.

In this exceptional case, however, the black hole was located about 2,600 light-years (0.8 kiloparsecs) from its host galaxy's core, evidence that supermassive black holes can lurk in unexpected places.

The discovery was made possible through high-quality observations from several of the world's premier radio telescopes, including the Very Large Array (VLA), ALMA, ATA, SMA, and the Arcminute Microkelvin Imager Large Array (AMI-LA) in the UK.

The AMI observations, led by the Hebrew University team, were crucial in revealing the unusually rapid evolution of the radio emission鈥攁 hallmark of this event and a major clue to understanding its physical nature.

The data showed two distinct radio flares evolving faster than any TDE observed before. These results indicate that powerful outflows of material were launched from the vicinity of the black hole not immediately after the stellar destruction, but months later, suggesting delayed and complex processes in the aftermath of the disruption.

Detailed modeling points to at least two separate ejection events, months apart鈥攃lear evidence that black holes can episodically "reawaken" after periods of apparent inactivity.