Scientists have found evidence of the existence of an intermediate-mass black hole in the 47 Tucanae (NGC 104) cluster:
All known black holes fall into two categories: small, stellar-mass black holes weighing a few Suns, and supermassive black holes weighing[1] millions or billions of Suns. Astronomers expect that intermediate-mass black holes weighing 100 - 10,000 Suns also exist, but so far no conclusive proof of such middleweights has been found. Today, astronomers are announcing new evidence that an intermediate-mass black hole (IMBH) weighing 2,200 Suns is hiding at the center of the globular star cluster 47 Tucanae.
"We want to find intermediate-mass black holes because they are the missing link between stellar-mass and supermassive black holes. They may be the primordial seeds that grew into the monsters we see in the centers of galaxies today," says lead author Bulent Kiziltan of the Harvard-Smithsonian Center for Astrophysics (CfA).
This work appears in the Feb. 9, 2017, issue of the prestigious science journal Nature [DOI: 10.1038/nature21361] [DX].
47 Tucanae is a 12-billion-year-old star cluster located 13,000 light-years from Earth in the southern constellation of Tucana the Toucan. It contains hundreds of thousands of stars in a ball only about 120 light-years in diameter. It also holds about two dozen pulsars that were important targets of this investigation.
This isn't the first time that scientists have thought they found an intermediate-mass black hole (see GCIRS 13E).
[1] Ed Note: Yes, I am aware that weigh is inappropriate in this context and that the proper term is mass. This is, however, a direct quote and that is what they wrote. --martyb
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A larger intermediate mass black hole may have been discovered in the Milky Way galaxy:
Astronomers have found the best evidence yet for the existence of a midsized black hole—long-rumored objects bigger than the small black holes formed from a single star, yet far smaller than the the giant ones lurking at the centers of galaxies—and it's hiding out in our own Milky Way. If the discovery is confirmed, it could indicate that our galaxy has grown by cannibalizing its smaller neighbors.
"It's a very careful paper and they have gorgeous data. It's the most promising evidence so far" for an intermediate mass black hole, says astronomer Kevin Schawinski of the Swiss Federal Institute of Technology in Zurich.
[...] Last year, a team led by Tomoharu Oka of Keio University in Yokohama, Japan, reported finding a peculiar cloud of molecular gas, called CO-0.40-0.22, near the center of our Milky Way. Gas in the cloud, detected with the National Astronomical Observatory of Japan's 45-meter Nobeyama radio telescope, was moving with a very wide range of velocities, some of it so fast that the team suspected something very massive was hiding there. Simulations of the gas movements suggested it harbored a black hole of 100,000 solar masses.
(Score: 3, Informative) by krishnoid on Friday February 10 2017, @11:54AM
I thought '[sic]' is what you use in this circumstance.
(Score: 3, Funny) by martyb on Friday February 10 2017, @02:08PM
Well, I considered that if I left it unmentioned, there would be a massive number of comments about the mistake, so I weighed the pros and cons of how to proceed. Seeing it was late and I am still recovering from being sick, I feared I might miss a spot if I flagged each instance, so I just called out the first instance with an explanatory footnote.
:)
Wit is intellect, dancing.
(Score: 2) by martyb on Friday February 10 2017, @02:13PM
I found this article interesting. We've identified black holes on the size of some small multiple of solar masses. And ones that are millions or billions(!) of solar masses. How do you get supermassive black holes? It would seem reasonable that solar-mass black holes acreted mass over time and grew into being supermassive black holes. But, if that IS the case, where are they? Why are we having so much difficulty finding them?
Curiouser and curiouser (with apologies to to Alice in Wonderland).
Are there any Soylentils who can shed some light on this mystery?
Wit is intellect, dancing.
(Score: 0) by Anonymous Coward on Friday February 10 2017, @04:28PM
I think there is some argument about whether black holes can form:
http://www.cscamm.umd.edu/tiglio/GR2012/Syllabus_files/EinsteinSchwarzschild.pdf [umd.edu]
The argument then goes, if they exist, they must be primordial (formed during the big bang)
(Score: 3, Interesting) by dry on Saturday February 11 2017, @05:03AM
I think there is some question whether super massive black holes formed by accretion. They seem to be around as far back as we can see, which doesn't leave much time for a black hole to eat the equivalent of 1% of the Milky Way, especially as galaxies seem to have been smaller then. Perhaps they're an artifact of the big bang?
What I find interesting is the global clusters, hundreds of thousands of stars contained in a volume of only 120 light years diameter. Imagine the sky, at least if a planet could form there (no metals). Must have been a pretty dense gas cloud to form so many stars as well as the black hole.
(Score: 0) by Anonymous Coward on Friday February 10 2017, @03:47PM
All Black Holes Matter.
(Score: -1, Troll) by Anonymous Coward on Friday February 10 2017, @04:22PM
... that NASA mistook her for a possible intermediate-mass black hole!
(Score: 0) by Anonymous Coward on Sunday February 12 2017, @12:22AM
issue of the prestigious science journal Nature
"prestigious" according to whom? The Science journal?
Extraordinary claims need extraordinary evidence, and Science, Nature and all space agencies and telescope facilities must be excluded for being their own and each other's peer reviewers.
I am relatively young so I guess I come across as arrogant, but I'm telling you actual science is almost dead thanks to this journal system.