Wednesday , January 19 2022

These "giant monsters" were observed suddenly by gasing their surroundings – ScienceDaily


Supermassive black holes weigh millions to billions of times more than our sun and are in most galaxies. The super-massive black hole in the millions of times the sun's mass lies in the center of our own Milky Way.

Regardless of how ordinary supermassive black holes are, it is still unclear how they grow in such a huge amount. Some black holes constantly swallow gas in their neighborhood, some suddenly swallowing whole stars. But no theory independently explains how supermassive black holes can unexpectedly "turn on" and continue to grow so fast for a long time.

Today, a new study led by Tel Aviv University has been published Natural astronomy notes that some supernatural black holes are activated to grow, suddenly eating large amounts of gas in their surroundings.

In February 2017, the All Sky automated Supernova study revealed an event known as AT 2017bgt. Initially, this event was thought to be a "star swallowing" event or "tide disturbance" event, as radiation emitted around a black hole increased more than 50 times brighter than in 2004.

However, following extensive observations using many telescopes, a team of researchers led by Dr. Benny Trakhtenbrot and Dr. Iair Arcavi, a TAU Raymond & Beverly Sackler School of Physics and Astronomy, concluded that AT 2017bgt represented a new way of "feeding" black holes.

"The sudden glare of AT 2017bgt resembled a tidal break," says Dr. Trakhtenbrot. "But we quickly realized that this time was something unusual. The first thread was an additional light component that had never been seen in tidal disturbances."

Dr Arcavi, who led the data collection, adds: "We followed this event for over a year with telescopes on Earth and in space, and what we saw did not match anything we saw before."

The observations coincided with Prof. Prof. Hagai Netzer's theoretical forecast, also at Tel Aviv University.

"We had anticipated in the 1990s that the black hole swallowing the gas from its surroundings could create the light elements visible here," says Prof. Netzer. "This new result is the first time the process was seen in practice."

Astronomers from the US, Chile, Poland, and the United States participated in observations and analyzes using three different space telescopes, including the new NICER telescope mounted on the International Space Station.

One of the ultraviolet images acquired during the frenzy of data mining was the enormous image of the Neil Gehrels Swift Observatory, noted by NASA, who is leading this space mission.

The research team identified two recent reports of "black" events in black holes that have the same emission properties as AT 2017bgt. These three events create a new and tantalizing black hole re-activation class.

"We are not yet sure of the cause of this dramatic and sudden increase in black hole feeding speed," concludes Dr. Trakhtenbrots. "There are many known ways to speed up the growth of giant black holes, but they usually take place over a long period of time."

"We look forward to discovering a lot more of these events and keeping track of multiple telescopes working at the same time," says Dr. Arcavi. "This is the only way to improve the image of our black hole growth to understand who is accelerating it, and will eventually solve the mystery of how these giant monsters are formed."

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