INSATIABLE black hole in Milky Way's heart crams hot gas into cavity
Restaurant at the end of the universe...
Space boffins have suggested the supermassive black hole at the centre of our galaxy may have a powerful appetite for hot gas.
The European Space Agency's Herschel telescope has captured far-infrared images which appear to show the black hole sucking in a huge cloud of gas.
One astronomer said it looked as if the hole was "cooking its dinner".
Set in a region known as Sagittarius A* at the middle of the Milky Way, the scarily huge hole has a mass of four million times that of our sun and is about 26,000 light-years away from earth. Nonetheless, this is by far the closest supermassive hole and is a source of fascination for space scientists.
Now the boffins hope their discovery will allow them to learn something about these interstallar maws.
"The black hole appears to be devouring the gas," said Paul Goldsmith, the U.S. project scientist for Herschel at NASA's Jet Propulsion Laboratory, which assists the ESA with their Herschel mission. "This will teach us about how supermassive black holes grow."
Herschel uses near-infra red frequencies to peer through the clouds of gas and dust that prevent telescopes from sending back actual photographic images of the Milky Way's heart.
At the turbulent centre, boffins were surprised to see gas heated to a temperature of about 1000°C, which is much hotter than the frigid interstellar gas clouds which float along at "tens of degrees" above absolute zero: -273.15°C.
This could be down to collisions between the highly magnetised gas clouds, or it could indicate they are swirling at ferociously high speeds, say astronomers.
Whilst looking at this gas, Herschel's operators noticed a relatively small stream of gas amounting to a few times larger than the mass of the earth, which appeared to be being sucked into the black hole.
Now they are hoping to see all this gas gobbled up, which could result in the black hole burping out x-rays.
“The observations are also consistent with streamers of hot gas speeding towards Sagittarius A*, falling towards the very centre of the Galaxy,” says Dr Goicoechea, of the Centro de Astrobiología, Spain, who is lead author of the paper which reported the results. “Our Galaxy’s black hole may be cooking its dinner right in front of Herschel’s eyes.”
It is thought that nearly all galaxies have a black hole at their centre. ®
Sag A* is actually pronounces Sagittarius A-star... the asterisk does not denote a footnote. We thought we'd put one here anyway.