The detailed mechanisms of how matter falls onto a black hole from outside the event horizon have been revealed in a new research paper.
As predicted by Einstein’s theory of gravity, there comes a point at which matter stops orbiting the black hole and falls straight down, rapidly hurtling beyond the point of no return.
Now, with X-ray data of an active black hole, we have finally seen evidence of the existence of this “subduction zone.”
“Einstein’s theory predicted this recent drop, but this is the first time we’ve been able to prove it happened.” says theoretical physicist Andrew Mummery From the University of Oxford in the United Kingdom.
“Think of it like a river turning into a waterfall – until now, we’ve been looking at the river. This is our first view of a waterfall.”
The matter making its way into a black hole does not follow a straight line. It swirls around, like swirling water, rising inexorably down the drain. This is not an idle analogy: the comparison is apt since scientists use swirling water to study the environments surrounding black holes.
Studying black holes themselves is a bit difficult, because the warped spacetime around them is so extreme.
But decades ago, Albert Einstein’s theoretical work predicted that matter, at a certain close distance to a black hole, would no longer be able to follow a stable circular orbit, and would fall straight down—like water over the edge of that same drain.
There’s no reason to believe this isn’t the case — matter has to cross the event horizon somehow, and Einstein’s theory of gravity has stood up to scrutiny across the board — but what astrophysicists aren’t sure is whether or not we will. able to detect it.
The work of Mummery and his colleagues had multiple parts. One such experiment was to develop simulations and numerical models that visualize the sunken area to reveal what type of light it emits. Next, they needed observational evidence containing the same low-zone emission.
The black hole in question was found in a system about 10,000 light-years away called MAXI J1820+070. This system contains a black hole with a mass of about 8.5 times the mass of the Sun – and a binary companion star, which the black hole strips material from as the two objects rotate, feeding in bursts. It appears as an X-ray flash.
Astronomers have been monitoring this black hole to better understand its behavior, so researchers had access to high-quality data obtained using X-rays. Nustar And The most beautiful Instruments in low Earth orbit. They focused in particular on the explosion that occurred in 2018.
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Previous studies have indicated that there is an additional glow detected in observations of this completely inexplicable explosion.
a Study 2020 He speculated that this glow might originate from within the innermost circular orbit, the diving zone. Mummery and his colleagues studied this glow with particular care, and found that it matched the emission they derived from their simulations.
Researchers say this finally confirms the existence of the sinking region, beyond a doubt, giving us a new probe of the intense gravitational system in the region just outside the black hole’s event horizon.
“What’s really exciting is that there are many black holes in the galaxy, and we now have a powerful new technique to use to study the strongest gravitational fields known.” Mummery says.
“We believe this represents an exciting new development in the study of black holes, allowing us to study the end zone surrounding them.
Only then can we fully understand the force of gravity. “This final drop of plasma occurs at the edge of the black hole and shows matter’s response to gravity at its strongest possible.”
The research was published in Monthly Notices of the Royal Astronomical Society.