Israeli researchers obtained radio radiation from a distant galaxy, which they say may fundamentally change people’s understanding of black hole behavior.
When stars approach black holes, they are in danger of being torn apart. If so, the black hole is expected to consume a lot of material, and this process is thought to be completed within a few days and lasts for several weeks.
However, physicists at the Hebrew University of Jerusalem and Tel Aviv University are proposing the possibility of an unexplained process that would cause some black holes to disappear for months or years before swallowing the end of a destroyed star remains.
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Assaf Horesh, a physicist at the Hebrew University, told The Times of Israel: “It seems that there is a physical process that we don’t understand yet, which leads to a long time between the destruction of stars and the accumulation of matter in black holes. time delay.”

Illustration of star torn by black hole. Then suck the stellar fragments onto the black hole. (Elen11 via iStock by Getty Images)
The peer-reviewed journal Nature Astronomy has just published research by Horesh, Iair Arcavi of Tel Aviv University and Brad Cenko, director of NASA’s Swift Space Telescope. After observing the light radiation produced by the destruction of a star in the Milky Way at a distance of 700 million light years in 2015, they began looking for radio emissions and hoped to detect it in a short time.
After the star is destroyed, physicists believe that it is common for some matter to enter the black hole that caused its death. As part of this process, the ejection caused by the magnetic field around the black hole forces other materials away. Assuming it bounces back at a high speed, this is thought to produce shock waves, which can generate radio radiation.

3D rendering of a black hole (Philipp Tur via iStock by Getty Images)
Scientists have experience and can detect this immediately after observing the destruction of a star on Earth, but Hores and his colleagues have finally broken new ground by detecting emissions within four years.
The lead author of the new study, Hores, said: “After the star was destroyed, we saw light radiation, and then there was no radiation for several months. “We decided to give it what we thought was the last shot. Six months later, a radio transmission suddenly appeared and disappeared for a year. ”

This figure shows the timeline for Israeli researchers to detect radio emissions after the star is destroyed. (Provided by Dr. Assaf Horesh, Dr. Iair Arcavi, etc.)
“Then, four years after the initial observation, we again found a very strong signal.”
He said this study shows that the period during which black holes consume stellar matter and throw back other matter (generating radio radiation in the process) is “more chaotic” than previously thought. He added that his team is seeking to expand the scope of the study by identifying more radio transmissions from various galaxies.