That Galaxy Next Door? It's Home to a Monster Black Hole (npr.org) 17
NPR reports on "a monster black hole that's been lurking unseen in the galaxy next door."
This appears to be the closest supermassive black hole outside our Milky Way galaxy, according to a report that's appearing in The Astrophysical Journal... "Now that there is strong evidence that it should be there, you can rest assured that we are very excitedly following up," says Jesse Han of the Center for Astrophysics, Harvard & Smithsonian, who led the study...
Han and his colleagues realized that this black hole must exist when they were studying so-called hypervelocity stars... [T]hey started out as normal stars that were part of a binary system, or two stars orbiting each other. When that kind of pair ventures too close to a supermassive black hole, says Han, "what can happen is one of the stars can get captured by the black hole. It is basically ripped apart from its companion." The bereft companion star, meanwhile, gets flung away, going at ridiculously high speeds. It's as if the black hole basically hurled it out of the galaxy.
And that explains some of what's happening in our own galaxy, writes Space.com: Tracing the trajectory of these super-speed stars using the European Space Agency's star-tracking Gaia satellite, the researchers discovered that around half of them were accelerated by the Milky Way's own supermassive black hole, Sagittarius A*. The other half, the team believes, likely fled to the outskirts of the Milky Way after a gravitational encounter with a supermassive black hole at the heart of the LMC separated these stars from their stellar binary partners.
"It is astounding to realize that we have another supermassive black hole just down the block, cosmically speaking," team leader Jesse Han of the Center for Astrophysics | Harvard & Smithsonian (CfA) said in a statement. "Black holes are so stealthy that this one has been practically under our noses this whole time."
"Their calculations suggest that the Large Magellanic Cloud must be harboring a black hole that's about 600,000 times the mass of our Sun," adds NPR. "That's smaller than the black hole at the center of the Milky Way, which is about 4 million times more massive than the Sun." Astronomers had previously thought the Large Magellanic Cloud should have a big black hole, but until now there's been no evidence of it, says Han... Now, though, astronomers have a better sense of where to hunt for any X-ray, radio, or visible-light signatures that are the telltale signs of an invisible black hole that's devouring everything nearby. "It is within the realm of possibilities that it is already detectable in radio and X-ray and optical," says Han. "We just haven't looked at the right place."
Han and his colleagues realized that this black hole must exist when they were studying so-called hypervelocity stars... [T]hey started out as normal stars that were part of a binary system, or two stars orbiting each other. When that kind of pair ventures too close to a supermassive black hole, says Han, "what can happen is one of the stars can get captured by the black hole. It is basically ripped apart from its companion." The bereft companion star, meanwhile, gets flung away, going at ridiculously high speeds. It's as if the black hole basically hurled it out of the galaxy.
And that explains some of what's happening in our own galaxy, writes Space.com: Tracing the trajectory of these super-speed stars using the European Space Agency's star-tracking Gaia satellite, the researchers discovered that around half of them were accelerated by the Milky Way's own supermassive black hole, Sagittarius A*. The other half, the team believes, likely fled to the outskirts of the Milky Way after a gravitational encounter with a supermassive black hole at the heart of the LMC separated these stars from their stellar binary partners.
"It is astounding to realize that we have another supermassive black hole just down the block, cosmically speaking," team leader Jesse Han of the Center for Astrophysics | Harvard & Smithsonian (CfA) said in a statement. "Black holes are so stealthy that this one has been practically under our noses this whole time."
"Their calculations suggest that the Large Magellanic Cloud must be harboring a black hole that's about 600,000 times the mass of our Sun," adds NPR. "That's smaller than the black hole at the center of the Milky Way, which is about 4 million times more massive than the Sun." Astronomers had previously thought the Large Magellanic Cloud should have a big black hole, but until now there's been no evidence of it, says Han... Now, though, astronomers have a better sense of where to hunt for any X-ray, radio, or visible-light signatures that are the telltale signs of an invisible black hole that's devouring everything nearby. "It is within the realm of possibilities that it is already detectable in radio and X-ray and optical," says Han. "We just haven't looked at the right place."
People in superdense houses shouldn't... (Score:1)
Seems a bit rude to cast shade on a neighboring galaxy for having a supermassive black hole, when as even the summary admits we are very much guilty of the same pleasure.
Oh great (Score:2)
This neighborhood has gone to shit.
Re: (Score:2)
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I Need Federal Money To Overcome (Score:1)
My new fears. Considering the rate of new fears incoming, I'm gonna need about 12 trillion dollars. Thanks!
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Perhaps galaxies are just ... (Score:2)
Perhaps galaxies are just the accretion disks of big black holes.
(In any case, this suggests any galaxy (with a central black hole will also have a few hypervelocity stars flying around in elliptical orbits from near the center to somewhere much farther out, or on hyperbolas off to bombard the neighborhood.
Nasty traffic problem.
I wonder if this is related to spiral arm or star /star cluster /cloud formation, creates some (currently mysterious) stellar event when one hits another star, or grows the star into
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... this suggests any galaxy (with a central black hole will also have a few hypervelocity stars flying around ... spiral arm or star /star cluster /cloud formation ...
And if so, this should have been going on since galaxies with central black holes were a thing - which is quite early. What might this mean for more recent inter- and galactic architecture?
Thought Andromeda was the Closest (Score:2)
NPR reports on "a monster black hole that's been lurking unseen in the galaxy next door."
"Their calculations suggest that the Large Magellanic Cloud must be harboring a black hole that's about 600,000 times the mass of our Sun,"
TIL the LMC is a galaxy.
https://en.wikipedia.org/wiki/... [wikipedia.org]
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I think the Andromeda SMBH is in the billion solar masses category.
SMBHs are normal (Score:2)
The reason I don't say "all galaxies" is that the mass of the SMBH is fairly closely related to the overall galaxy mass, and the smaller galaxies have SMBHs that are too small to be easily seen from here. It's not as if they're outstandingly visible from inside the galaxy - "ours" was only clearly discovered in the 1970s, and proven to be an SMBH (not some other astronomical phenomenon) in the 1990s.
There is a
Why is LMC at the bottom of the summary? (Score:2)
Why is the first mention of the specific "galaxy next door" (the Large Magellanic Cloud) at the bottom of the summary?
This is supposed to be news for nerds. We know what the Large Magellanic Cloud is. Meanwhile the "summary" buries this information further in its text than TFA!
Are black holes like the nucleus of atoms? (Score:2)
The Bigger Picture: Are the Smallest and Largest Things Similar?
This idea aligns with a broader fractal-like structure in nature, where similar patterns appear at different scales. Some physicists even suspect that gravity and quantum mechanics are fundamentally linkedâ"possibly through ideas like holography or the AdS/CFT correspondence (which suggests black holes may have an underlying quantum description).