Black hole destroys corona
- Reference: 1595060586
- News link: https://www.theregister.co.uk/2020/07/18/black_hole_corona/
- Source link:
An international team of scientists have been observing the hole, 1ES 1927+654, for years. It’s estimated to be roughly 19 million solar masses, and is classified as an active galactic nucleus (AGN), which is a particularly bright type of supermassive black hole.
They also observed its corona, which is a ring of hot, energetic particles that reach a billion degrees and is about 100 million light years from Earth. It encircles the hole's event horizon.
The boffins lately realized the ring's brightness was dimming far faster than thought possible, plummeting by a factor of 10,000 in just a year to a low by July 2018.
[1]
Now you see me, now you don't ... An illustration of the black hole losing its corona after a star wanders too close. Image credit: NASA/JPL-Caltech
“We expect that luminosity changes this big should vary on timescales of many thousands to millions of years,” [2]said Erin Kara, co-author of a [3]study into the hole [4]just published in The Astrophysical Journal, and an assistant professor of physics at MIT.
“But in this object, we saw it change by 10,000 over a year, and it even changed by a factor of 100 in eight hours, which is just totally unheard of and really mind-boggling.”
X-ray telescopes, such as NASA’s Neutron star Interior Composition Explorer ( [5]NICER ) onboard the International Space Station, and ESA’s XMM-Newton Observatory, were pointed at the hole and detected less and less light from the corona. The ring appeared to have virtually disappeared at one point, something scientists have never seen happening before with black holes.
The surprises didn’t stop there. After 1ES 1927+654’s corona went dark, the black hole began collecting nearby material to repair its inner accretion disk. In just a couple of months, its corona returned and appeared almost as bright as before.
This will be really important to understanding how a black hole’s corona is heated and powered in the first place
“This seems to be the first time we’ve ever seen a corona first of all disappear, but then also rebuild itself, and we’re watching this in real-time,” Kara said. “This will be really important to understanding how a black hole’s corona is heated and powered in the first place.”
The astronomers aren’t quite sure what caused the black hole to blink. They believe that a star may have ventured too close to the black hole's event horizon and was pulled apart. The leftover pieces bounced around "like a pebble tossed into a gearbox" and disrupted the black hole’s accretion disk.
“My best guess is that a star got too close to that supermassive black hole, and because of the strong gravitational field of the black hole, the star got ripped apart,” Kara told The Register this week. "That stellar debris was on a collision course with the black hole accretion disk, and when it collided, the inner disk was disturbed, causing all that disk material and the corona to plunge into the black hole."
Scientists know what coronas are made up of yet they don’t really know how they’re formed. Kara hopes that black hole’s odd behavior might shed light on the process, adding: “The funny thing is, we don’t know what creates a corona around any black hole. How are those electrons so hot in the first place?
“The fact that we are watching one build up, nearly from scratch, almost back to its normal luminosity is a really big deal.
"I think it's likely that the corona is heated by magnetic fields in the inner accretion disk that get twisted up into a hot mess. When the accretion disk plunged into the black hole, so did those magnetic fields. Then after that violent episode, things are starting to renormalize, and those magnetic fields are starting to rearrange themselves.” ®
Get our [6]Tech Resources
[1] https://regmedia.co.uk/2020/07/18/black_hole_larger.jpg
[2] https://news.mit.edu/2020/black-hole-corona-reappear-0716
[3] https://arxiv.org/abs/2007.07275
[4] https://iopscience.iop.org/article/10.3847/2041-8213/ab91a1
[5] https://www.nasa.gov/nicer/
[6] https://whitepapers.theregister.com/
Re: In Real Time?
You know what was meant.
Re: In Real Time?
I would have expected better from a member of the scientific community.
Re: In Real Time?
"Real time" just means 1 second per elapsed second. It doesn't necessarily mean at the time it's being observed.
Re: In Real Time?
What exactly does "now" mean, in this context?
How does anything ever fall into a black hole, if it takes infinitely long to cross the event horizon? Surely all the mass would sort of bunch up like, an atoms width above it? :x
I believe this is one of those counterintuitive examples of relativity. Whilst you will never see an object cross the event horizon (it will just be red-shifted to Kingdom Come to the point of invisibility) it’s plain sailing from the object’s point of view. It will just pass through the event horizon like it will in any other regular patch of space. Never to leave again, of course.
I believe Space and Time sort of flip-flop once you cross the event horizon, if we're to trust Roger Penrose. That's difficult for me to grasp. Outside the black hole, time seems to go on for infinity. If that flips inside the black hole, then space would go on for ... nearly infinity. There's plenty of room to not bunch up. I haven't slept in a long while, so feel free to disregard this as nonsense.
Reverse the Polarity cures all
It just dimmed when the star ship it had captured reversed its polarity to escape. I get all my scientific knowledge from Star Trek and Dr. Who.
Boggle of the Day
I'm still trying to sort out "a particularly bright type of supermassive black hole."
Re: Boggle of the Day
I assumed the brightness was the accretion disc, otherwise if nothing was being dragged into range you wouldn’t be able to observer it.
Re: Boggle of the Day
Start with a black hole. It is black. Put a star in orbit next to it. The side of the star closest to the hole experiences more gravity and is pulled closer to the black hole. The side of the star further from the black hole experiences less gravity and moves further out. The inside track around the black hole is shorter so stuff on the inside pulls ahead. The outside track is longer so stuff falls behind. Quickly the star becomes a disk around the black hole like the rings around Saturn.
Saturn's rings are in every way on different scales from a black hole accretion disk. Saturn is a huge, a lightweight and it takes hours to days for ice to slowly orbit Saturn. Bits of Saturn's rings occasionally collide with each other. Bits of an accretion disk rub against their neighbours continuously. Lots more mass, tiny distances and everything going really fast. The friction heats the disk up till it glows. We are not talking boring red hot, sun-yellow hot or blue super giant hot. The colour for this temperature is X-rays. Enough X-rays to push stuff away from the accretion disk and limit the rate at which a black hole can grow (yes really - lumps of light pushing stellar masses away from the intense gravity near a black hole).
The black hole is still black but people talk about light 'from a black hole' when they mean light 'from an accretion disk'. No wonder people get confused and think scientists contradict themselves faster than a president.
Re: Boggle of the Day
> I'm still trying to sort out "a particularly bright type of supermassive black hole."
They just mean it's quite intelligent.
Magic cure
No one tell Trump about this, or he'll be touting black holes as a cure for COVID-19.
" Black hole destroys corona "? So when is Trump going to promote injecting Black Holes as a cure for the Corona Virus?
In Real Time?
“This seems to be the first time we’ve ever seen a corona first of all disappear, but then also rebuild itself, and we’re watching this in real-time,” Kara said. “ Real time? More like 100million years ago. This thing doesn't even exist now :-)