Artist's conception of the binary supermassive black hole system. Credit P. Marenfeld, NOAO
Artist's conception of the binary supermassive black hole system. Credit P. Marenfeld, NOAO

Black Holes, galaxies

Astronomers Detect Two Black Holes in a Cosmic Dance

4 Mar , 2009 by

Artist's conception of the binary supermassive black hole system. Credit P. Marenfeld, NOAO

Paired black holes are theorized to be common, but have escaped detection — until now.

Astronomers Todd Boroson and Tod Lauer, from the National Optical Astronomy Observatory (NOAO) in Tucson, Arizona, have found what looks like two massive black holes orbiting each other in the center of one galaxy. Their discovery appears in this week’s issue of Nature.

Astronomers have long suspected that most large galaxies harbor black holes at their center, and that most galaxies have undergone some kind of merger in their lifetime. But while binary black hole systems should be common, they have proved hard to find.  Boroson and Lauer believe they’ve found a galaxy that contains two black holes, which orbit each other every 100 years or so. They appear to be separated by only 1/10 of a parsec, a tenth of the distance from Earth to the nearest star. 

After a galaxy forms, it is likely that a massive black hole can also form at its center. Since many galaxies are found in cluster of galaxies, individual galaxies can collide with each other as they orbit in the cluster. The mystery is what happens to these central black holes when galaxies collide and ultimately merge together. Theory predicts that they will orbit each other and eventually merge into an even larger black hole.

“Previous work has identified potential examples of black holes on their way to merging, but the case presented by Boroson and Lauer is special because the pairing is tighter and the evidence much stronger,” wrote Jon Miller, a University of Michigan astronomer, in an accompanying editorial.

The material falling into a black hole emits light in narrow wavelength regions, forming emission lines which can be seen when the light is dispersed into a spectrum. The emission lines carry the information about the speed and direction of the black hole and the material falling into it. If two black holes are present, they would orbit each other before merging and would have a characteristic dual signature in their emission lines. This signature has now been found.

The smaller black hole has a mass 20 million times that of the sun; the larger one is 50 times bigger, as determined by the their orbital velocities.

Boroson and Lauer used data from the Sloan Digital Sky Survey, a 2.5-meter (8-foot) diameter telescope at Apache Point in southern New Mexico to look for this characteristic dual black hole signature among 17,500 quasars. 

Quasars are the most luminous versions of the general class of objects known as active galaxies, which can be a hundred times brighter than our Milky Way galaxy, and powered by the accretion of material into supermassive black holes in their nuclei. Astronomers have found more than 100,000 quasars.

Boroson and Lauer had to eliminate the possibility that they were seeing two galaxies, each with its own black hole, superimposed on each other. To try to eliminate this superposition possibility, they determined that the quasars were at the same red-shift determined distance and that there was a signature of only one host galaxy.

“The double set of broad emission lines is pretty conclusive evidence of two black holes,” Boroson said. “If in fact this were a chance superposition, one of the objects must be quite peculiar.  One nice thing about this binary black hole system is that we predict that we will see observable velocity changes within a few years at most.  We can test our explanation that the binary black hole system is embedded in a galaxy that is itself the result of a merger of two smaller galaxies, each of which contained one of the two black holes.”  

LEAD IMAGE CAPTION (more): Artist’s conception of the binary supermassive black hole system. Each black hole is surrounded by a disk of material gradually spiraling into its grasp, releasing radiation from x-rays to radio waves.  The two black holes complete an orbit around their center of mass every 100 years, traveling with a relative velocity of 6000 kilometers (3,728 miles) per second.  (Credit P. Marenfeld, NOAO)

Source: NOAO

 

 

 

 

 

By
Anne Minard is a freelance science journalist with an academic background in biology and a fascination with outer space. Her first book, Pluto and Beyond, was published in 2007.


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Anaconda
Member
Anaconda
March 4, 2009 2:57 PM
Many people (scientists are people, too, you know) don’t buy into “black holes”. The idea that a so-called accretion disk (out side the so-called event horizon) can generate the prodigous amounts of electromagnetic energy has never been quantified. Nor is there any experimental basis to suggest a so-called accretion disk, i. e., a result of gravity, can generate electromagnetism on this prodigous scale. Let’s do some comparison: Cygnus X-1 was the first so-called “black hole”. When you scrub down Cygnus X-1 to bare facts which are observable & measurable all science has is it’s intense and somewhat fluctuating x-ray signature.” What observations & measurements are there for these objects in the present post if you scrub down all… Read more »
Total Science
Member
March 4, 2009 12:41 PM

Utterly absurd.

If black holes suck in light, how did they detect and observe them? With a crystal ball?

At 1/10 a parsec distance from eachother how come the massive black holes don’t fall on eachother by their overwhelming gravitational pull?

The article alleges that material falls into black holes but at 1/10th of a parsec the black holes aren’t falling into eachother.

Rather they are orbiting eachother regularly, thus defying Newton’s occult so-called law of gravitation.

Andy
Guest
Andy
March 4, 2009 12:55 PM

Wiki “orbital mechanics”.

collin
Guest
collin
March 4, 2009 12:59 PM

@OillsMastery:

It’s my understanding that these objects are observed indirectly since, as you point out, black holes trap everything including light. Astronomers look at how the objects around the area in question are behaving and deduce that a large, super-dense body is present. If there is another explanation for things like Quasars or unseen gravitational bodies, I’d love to hear it.

Wouldn’t this situation be possible if the two black holes are outside of each other’s respective event horizons?

I pride myself on keeping an open mind about the nature of the universe and being willing to entertain exotic explanations/different theories regarding it, but I wouldn’t say black holes are outside the realm of possibility.

Geoff of Essex
Member
Geoff of Essex
March 4, 2009 1:09 PM

One parsec is 3.26 light years. The nearest star beyond the Sun is Proxima Centauri at about 4 to 4.2 light years. Unless there is a ‘star’ closer then saying 1/10th of a parsec is the same as 1/10th the distance to the nearest star doesn’t compute There seems to be a discrepency of about 28%. Using navigation like that on a flight from London to New York would put you somewhere between the equator and the north pole. Not a small matter, I wouldn’t have thought. Try going fom New York to Los Angeles on that kind of accuracy.

Jorge
Guest
March 4, 2009 1:39 PM
Utterly absurd. If black holes suck in light, how did they detect and observe them? With a crystal ball? That’s actually answered in the article: The material falling into a black hole emits light in narrow wavelength regions, forming emission lines which can be seen when the light is dispersed into a spectrum. Supposing you can read, there you go. Black holes may “suck in light”, but that’s within their event horizons. The matter falling in is outside the event horizon, and therefore we can detect the light it emits. At 1/10 a parsec distance from eachother how come the massive black holes don’t fall on eachother by their overwhelming gravitational pull? Ever heard of something called “orbit”?… Read more »
Geoff of Essex
Member
Geoff of Essex
March 4, 2009 2:00 PM

Error correction to my last comment. London to New York is about 3600 miles / 5760 km apart, and 28% of that is around 1000 miles / 1600 km or about 17 degrees of latitude range; which means that with New York being about 40 degrees North – you could end up some where between 23 and 57 degrees North – still a substantial navigation error don’t you think.

Calib
Guest
Calib
March 4, 2009 2:11 PM
@Jorge: Great work on clearing up Oilsmastery’s obvious delusions for the people here who havent experienced his craziness…unfortunately with people like them, their minds can never be swayed with logic, vast amounts of evidence, reason, and all the good things that are the hallmarks of Science. Ive been following his previous posts on UT, and his unbelievably delusional blog…he has the mindset of a creationist. You know, the rants against “mainstream science”, the attacks on anything that goes against his superstitious magic believing worldview….im sure evolutionary biologists the world over have experienced these sorts of people too. If it wasnt for all that wasted effort he put into his blog, i would discount him as a Troll trying… Read more »
Total Science
Member
March 4, 2009 2:21 PM

Jorge,

Falsified hypothesis: Material falls into a black hole by gravitation.

Actual observation: Alleged “black holes” orbit eachother.

Rob Bowman
Member
March 4, 2009 2:22 PM

Dear UT staff – can we see about having “OillsMastery” blocked. He’s a plonker. Thanks.

Total Science
Member
March 4, 2009 2:34 PM

Rob,

Why do you think censorship = science?

Been reading Mein Kampf lately?

Dave Finton
Member
March 4, 2009 2:36 PM

I have to agree with Rob. It’s one thing to have an alternate opinion, but OillsMastery has been literally spamming every UT thread for a while. His rants are long-winded and not very logical (see above), he has an agenda, and he is deliberately trying to drown out reasonable discussion. It’s not a rarity to see him take up almost half the posts in a thread.

Trippy
Member
Trippy
March 4, 2009 2:45 PM

OIM:
There’s this small thing called angular momentum that means that when an object falls into a black hole, it doesn’t fall in a straight line like your limited experience on this small ball of rock would seem to indicate it should.

It tends to follow a curved path.

Total Science
Member
March 4, 2009 2:47 PM

Trippy,

So according to you, material doesn’t fall into the alleged black holes?

Davidlpf
Guest
Davidlpf
March 4, 2009 2:58 PM

Using creationists tactics OiM. Calling people Nazis because they do not like what they are saying about you.

Total Science
Member
March 4, 2009 3:07 PM

Davidlpf,

“Using creationists tactics OiM.”

Newton and Lemaitre are the creationists. I deny their tactics.

“Calling people Nazis because they do not like what they are saying about you.”

You are lying. I didn’t call anyone a Nazi because I don’t like what they are saying about me. I called someone a Nazi for advocating censorship in science. But this isn’t about me this is about the myth of gravitation so please refrain from ad hominem fallacies and try to come up with a logical or scientific counteragrument for why you believe in 17th century occult forces and miracles.

Olaf
Member
Olaf
March 4, 2009 3:08 PM

“Rather they are orbiting eachother regularly, thus defying Newton’s occult so-called law of gravitation.”

This proves it, he has no clue of the even simplest laws from Newton!

Ok time not to feed the trolls!
Ignore mode on!

Total Science
Member
March 4, 2009 3:14 PM

Olaf,

I can assure you I understand the “simplest laws from Newton.”

Since you seem to be either unable or afraid to discuss the so-called “simplest laws from Newton,” here is an actual quote from Newton”s Principia, Book III, General Scholium:

“…lest the systems of the fixed stars should, by their gravity, fall on each other, he [God] hath placed those systems at immense distances from one another.” — Isaac Newton, mathematician, 1687

As I said, utterly absurd.

Davidlpf
Guest
Davidlpf
March 4, 2009 3:20 PM

@OiM maybe people would treat you better if did not start off with “Utterly absurd”.

And about things failing down the potential well of black hole in spiral fashion you say things do not fall down like that. How do you explain whirlpools.

Total Science
Member
March 4, 2009 3:28 PM

Davidlpf,

I really don’t care how people treat me because despite what the mainstream pseudoscientists here might think, this isn’t about me, despite the multitude of long winded ad hominem fallacies devoid of all logical and scientific counterargument.

This is about science, conjectures, and refutations — namely Isaac Newton’s occult 17th century myth of universal gravitation and the myth of black holes.

“How do you explain whirlpools.”

Very easily. See Winston Bostick and Anthony Peratt’s work on plasmoids and plasma vortices.

wpDiscuz