Feeds

Hidden black holes elude astronomers

Living up to their name, then

Choosing a cloud hosting partner with confidence

It would seem, to the casual observer, a relatively simple thing to keep track of something with a mass millions of times that of our sun, but astronomers are having trouble locating supermassive black holes in neighbouring galaxies.

The researchers, from the US and Europe, suggest that either black holes are better hidden than scientists have thought, or they are only to be found on the outskirts of the universe.

A supermassive blackhole surrounded by a dusty torus

Hidden supermassive black holes have been used to explain the universe's background X-ray radiation. The theory is that black holes are hiding behind huge clouds of dust capable of absorbing all but the highest energy X-ray radiation. Once these X-Rays make it out from behind the shrouds of dust, they combine to form the high energy peaks in the radiation that permeates the universe.

However, researchers working on a high energy census of our skies have not been able to find enough of the hidden black holes to account for all the observed radiation.

In January this year Italian astronomers used the European Space Agency's International Gamma Ray Astrophysics Laboratory, Integral, to show that the fraction of black holes in the nearby universe that are hidden behind these clouds of dust is around 15 percent.

Now a team of US and Swiss astronomers from NASA Goddard Space Flight Center in Greenbelt, Maryland, and the Integral Science Data Centre near Geneva, have analysed two years of continuous data from Integral and concluded that the proportion of hidden black holes could be as low as one in ten.

"Naturally, it is difficult to find something we know is hiding well and which has eluded detection so far," says Volker Beckmann of NASA Goddard. "Integral is a telescope that should see nearby hidden black holes, but we have come up short."

There are a few possible explanations. First, that if hidden black holes are responsible for the observed energy, that they are hidden further away. It could be that nearby supermassive black holes have had time to consume all the dust that would have shrouded them. Since the X-rays are produced by matter falling into the black holes, these naked black holes would not produce any.

Another possibility is that the black holes are just more hidden than astronomers realised, and are below the detection capabilities even of Integral.

NASA says more work is planned, and that the Swift satellite, in orbit to detect Gamma Ray Bursters, should be able to provide useful data. ®

Secure remote control for conventional and virtual desktops

More from The Register

next story
GRAV WAVE DRAMA: 'Big Bang echo' may have been grit on the scanner – boffins
Exit Planet Dust on faster-than-light expansion of universe
Mine Bitcoins with PENCIL and PAPER
Forget Sudoku, crunch SHA-256 algos
SpaceX Dragon cargo truck flies 3D printer to ISS: Clawdown in 3, 2...
Craft berths at space station with supplies, experiments, toys
'This BITE MARK is a SMOKING GUN': Boffins probe ancient assault
Tooth embedded in thigh bone may tell who pulled the trigger
DOLPHINS SMELL MAGNETS – did we hear that right, boffins?
Xavier's School for Gifted Magnetotaceans
Big dinosaur wowed females with its ENORMOUS HOOTER
That's right, Doris, I've got biggest snout in the prehistoric world
Japanese volcano eruption reportedly leaves 31 people presumed dead
Hopes fade of finding survivors on Mount Ontake
That glass of water you just drank? It was OLDER than the SUN
One MEELLION years older. Some of it anyway
Canberra drone team dances a samba in Outback Challenge
CSIRO's 'missing bushwalker' found and watered
prev story

Whitepapers

Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Storage capacity and performance optimization at Mizuno USA
Mizuno USA turn to Tegile storage technology to solve both their SAN and backup issues.
The next step in data security
With recent increased privacy concerns and computers becoming more powerful, the chance of hackers being able to crack smaller-sized RSA keys increases.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.
A strategic approach to identity relationship management
ForgeRock commissioned Forrester to evaluate companies’ IAM practices and requirements when it comes to customer-facing scenarios versus employee-facing ones.