Feeds

Stargazers spy elusive binary black hole system

Two monsters circling in distant quasar

High performance access to file storage

Astronomers at the National Optical Astronomy Observatory (NOAO) believe they've spotted a binary black hole system - two monsters orbiting each other at the centre of a quasar* 5bn light-years from Earth.

Artist's impression of the binary black hole system

NOAO explains that galaxies commonly form with a black hole at their heart, and if they're part of a cluster of galaxies, collisions are likely. What's not certain is what then happens to the two black holes, although NOAO notes that theoretically "they will orbit each other and eventually merge into an even larger black hole".

Such phenomena have hitherto proved elusive, until NOAO astronomers Todd Boroson and Tod Lauer scoured the Sloan Digital Sky Survey, which encompasses 17,500 quasars, for the "characteristic dual black hole signature".

NOAO elaborates: "The signature of a black hole in a galaxy has been known for many years. The material falling into a black hole emits light in narrow wavelength regions forming emission lines that can be seen when the light is dispersed into a spectrum.

"These 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 quasar in question is J1536+0441, lying in the direction of the constellation Serpens Caput, which shows "two sets of broad hydrogen spectral lines", as New Scientist puts it. To make sure they weren't seeing two galaxies "superimposed on each other", Boroson and Lauer "determined that the quasars were at the same red-shift determined distance and that there was a signature of only one host galaxy".

Boroson said: “The double set of broad emission lines is pretty conclusive evidence of two black holes. If in fact this were a chance superposition, one of the objects must be quite peculiar."

The two black holes "appear to be separated by only 1/10 of a parsec - a tenth of the distance from Earth to the nearest star", and have an orbital period of almost 100 years. They weigh in at 107.3 and 108.9 solar masses or, as NOAO puts it: "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's work appears in this week's Nature. The abstract can be found here. ®

Bootnote

*NOAO nicely explains: "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. The matter falling into the black hole doesn’t go directly in, but orbits around the black hole forming a flat accretion disc, much like the soap scum on water orbiting around an open drain."

High performance access to file storage

More from The Register

next story
Fancy joining Reg hack on quid-a-day challenge?
Recruiting now for charity starvation diet
Red-faced LOHAN team 'fesses up in blown SPEARS fuse fiasco
Standing in the corner, big pointy 'D' hats
KILLER SPONGES menacing California coastline
Surfers are safe, crustaceans less so
LOHAN's Punch and Judy show relaunches Thursday
Weather looking good for second pop at test flights
Discovery time for 200m WONDER MATERIALS shaved from 4 MILLENNIA... to 4 years
Alloy, Alloy: Boffins in speed-classification breakthrough
Elon Musk's LEAKY THRUSTER gas stalls Space Station supply run
Helium seeps from Falcon 9 first stage, delays new legs for NASA robonaut
Top Secret US payload launched into space successfully
Clandestine NRO spacecraft sets off on its unknown mission
New FEMTO-MOON sighted BIRTHING from Saturn's RING
Icy 'Peggy' looks to be leaving the outer rings
prev story

Whitepapers

Top three mobile application threats
Learn about three of the top mobile application security threats facing businesses today and recommendations on how to mitigate the risk.
Combat fraud and increase customer satisfaction
Based on their experience using HP ArcSight Enterprise Security Manager for IT security operations, Finansbank moved to HP ArcSight ESM for fraud management.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
SANS - Survey on application security programs
In this whitepaper learn about the state of application security programs and practices of 488 surveyed respondents, and discover how mature and effective these programs are.