Hebrew University finds first evidence of delayed radio rockets after star is destroyed by black hole

A team of researchers from the Hebrew University of Jerusalem (HUJI) led by Dr Assaf Horesh discovered the first evidence of radio rockets emitted only long after a star was destroyed by a black hole. Published in the periodical Nature astronomy, the discovery relied on ultra-powerful radio telescopes to study these catastrophic cosmic events in distant galaxies called Tidal Disruption Events (TDE). While the researchers knew these events triggered the release of radioactive rockets, this latest discovery saw these rockets be released months or even years after the stellar disturbance. The team was led by Dr Horesh of the Racah Hebrew Institute of Physics with the director of NASA’s Swift Space Telescope, Professor Brad Cenko and Dr Iair Arcavi of Tel Aviv University.

“According to existing theories as to how these events occur, if no radio broadcasts were discovered in the immediate wake of the disruption, there is no expectation that it will happen later,” says Dr Horesh . “However, we decided to do a final radio observation six months after the star’s destruction, and surprisingly, we discovered a brilliant radio show. Once we discovered this delayed radio rocket, we continued to collect data for a year, during which the radio broadcast faded. In addition, we found a second delayed rocket, four years after the initial discovery of stellar disturbance. This is the first discovery of such radio rockets. delayed from such events, when a star is disturbed by a black hole. “

Flares are believed to be caused by a huge jet of speed launched when the star is destroyed and sucked into the black hole or as a result of the debris from the explosion exploding outward.

The analysis of the delayed radio rockets led the research team to several conclusions.

First, they now believe that new models must be developed to explain such a long delay in emission from radio torches. Second, it is possible that these delayed radio flares are a common occurrence, but to find more of them, teams will need to stay focused on sightings surrounding affected areas long after the initial disturbance. Third, it is possible that a substantial amount of stellar debris will eventually be accreted (drawn) into the black hole, but only long after the star has been destroyed.

“What led to the delay and what the exact physical process responsible for these late emissions is are still open questions,” says Dr Horesh. “In light of this finding, we are actively looking for more delayed radio rockets in other tidal disturbance events.”

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