Black holes should not make flashes of light. It’s right there in the name: black holes.
Even when bumping into each other, huge objects should be invisible to traditional astronomers’ tools. But when scientists detected a black hole collision last year, they also noticed a strange glow from the accident.
On May 21, 2019, Earth’s gravitational wave the detectors have captured the signal of a pair of huge objects colliding, sending ripples that fall into space-time. Later, an observatory called the Zwicky Transient Facility (ZTF) captured an explosion of light. As the scientists looked at the two signals, they realized that both were from the same area of sky and the researchers began to wonder if they had spotted the rare visible collision of the black hole.
“This finding is extremely exciting,”
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Here’s what scientists think in this strange case. The two black holes that joined have been stuck in the disc surrounding it quasar, a supermassive black hole that shoots bursts of energy.
“This supermassive black hole was leaping for years before this more sudden glow,” Matthew Graham, Caltech astronomer and scientist of the ZTF project, said in a university statement.
This in itself is not so strange, according to his colleague. “Supermassive black holes like this always have flares,” said co-author Mansi Kasliwal, an astronomer from Caltech. “They are not silent objects, but the timing, size and location of this glow have been spectacular.”
Scientists suspect, based on the combination of gravitational waves and light, that the glow emerged from two small black holes that merge within the accretion disk of the supermassive black hole. The incredibly strong gravity of the supermassive black hole affects the smallest things on the disc, even other black holes.
“These objects swarm like angry bees around the monstrous queen bee in the center,” said co-author KE Saavik Ford of the City University of New York Graduate Center, the Borough of Manhattan Community College and the American Museum of Natural History statement. “They can find gravitational partners briefly and mate, but usually they quickly lose their partners to the crazy dance. But in a supermassive black hole disc, the flowing gas converts the swarm mosh well into a classic minuet, organizing black holes. so it can mate. “
The flash of light does not come the merger itself, scientists think. Instead, the force of the fusion makes the now larger black hole fly away, through the gas that surrounds it in the accretion disk of the supermassive black hole. The gas, in turn, produces the glow after a delay of days or weeks, the theory goes according to the statement. In the case of this event, scientists detected the glow about 34 days after the gravitational wave signal.
There’s no guarantee that this explanation fits what happened, the researchers said.
“The glow occurred on the correct time scale and in the correct position, to coincide with the gravitational wave event,” said Graham. “We conclude that the glow is probably the result of a black hole merger, but we cannot completely rule out other possibilities.”
The results are described in a document published Thursday (June 26) in the journal Physical Review Letters.