Lone Wolf
19th September 2008, 08:47 AM
Durham University scientists discover black holes’ missing link...
For years astronomers speculated that a giant, mysterious force lay at the centre of the Milky Way, but it wasn’t until five years ago that the American astronomer Andrea Ghez definitively showed it was. Using new techniques for peering into the dusty heart of the galaxy, Ghez’s observations proved that scores of stars were orbiting what could only be a black hole. This wasn’t the kind of black hole created when a star explodes and dies, it was hundreds of thousands of times as powerful – a super-massive black hole, as they are known.
Now scientists at Durham University have found the missing link between small and massive black holes. For the first time researchers have discovered that a strong x-ray pulse is emitting from a giant black hole in a galaxy 500 light years distant from Earth.
X-ray pulses are common among smaller black holes, but the Durham research is the first to identify this activity in a super-massive black hole. Most galaxies, including the Milky Way, are believed to contain super-massive black holes at their centres. The researchers, who publish their findings in the prestigious scientific journal Nature Today say their discovery will increase the understanding of how gas behaves before falling into a black hole as it feeds and develops.
Dr Marek Gierlinsky, of Durham University’s Department of Physics, said: “Such signals are a well-known feature of smaller black holes in our galaxy when gas is pulled from a companion star. “The really interesting thing is that we have now established a link between these lightweight black holes and those millions of times as heavy as our sun. “Scientists have been looking for such behaviour for the past 20 years and our discovery helps us begin to understand more about the activity around black holes as hey grow.” Durham’s scientists hope research will tell them why some super-massive black holes show this behaviour while others do not.
The research was funded by the science and Technology Facilities Council, The European Space Agency and Polish Ministry of Science and Higher Education.
For years astronomers speculated that a giant, mysterious force lay at the centre of the Milky Way, but it wasn’t until five years ago that the American astronomer Andrea Ghez definitively showed it was. Using new techniques for peering into the dusty heart of the galaxy, Ghez’s observations proved that scores of stars were orbiting what could only be a black hole. This wasn’t the kind of black hole created when a star explodes and dies, it was hundreds of thousands of times as powerful – a super-massive black hole, as they are known.
Now scientists at Durham University have found the missing link between small and massive black holes. For the first time researchers have discovered that a strong x-ray pulse is emitting from a giant black hole in a galaxy 500 light years distant from Earth.
X-ray pulses are common among smaller black holes, but the Durham research is the first to identify this activity in a super-massive black hole. Most galaxies, including the Milky Way, are believed to contain super-massive black holes at their centres. The researchers, who publish their findings in the prestigious scientific journal Nature Today say their discovery will increase the understanding of how gas behaves before falling into a black hole as it feeds and develops.
Dr Marek Gierlinsky, of Durham University’s Department of Physics, said: “Such signals are a well-known feature of smaller black holes in our galaxy when gas is pulled from a companion star. “The really interesting thing is that we have now established a link between these lightweight black holes and those millions of times as heavy as our sun. “Scientists have been looking for such behaviour for the past 20 years and our discovery helps us begin to understand more about the activity around black holes as hey grow.” Durham’s scientists hope research will tell them why some super-massive black holes show this behaviour while others do not.
The research was funded by the science and Technology Facilities Council, The European Space Agency and Polish Ministry of Science and Higher Education.