R-iZZy
08-19-2005, 08:09 AM
A team of astronomers from the Netherlands, the United Kingdom and the United States has discovered a huge ‘bubble’ in the gas around a black hole in the Milky Way. A jet from the black hole blows this gas bubble. The discovery shows that scientists have been severely underestimating how much energy is pumped back into the universe by black holes. The discovery was published in ‘Nature’ on 11 August, with UvA-astronomer Elena Gallo as lead author.
The bubble was discovered through radio-astronomical observations with ASTRON’s Westerbork Synthese Radio Telescope (WSRT). The observations centred on the well known roentgen double star Cygnus X1 which is known to be close to a black hole. The bubble was also perceived in optical observations of the Anglo-Dutch 2.5m Isaac Newton Telescope on the Canary Islands.
Formation of the bubble
The bubble is approximately ten light years across and is predicted to be increasing with a speed of around a hundred kilometers per second. The bubble seems to have been formed by a jet, a powerful stream of energy and matter originating in the black hole, in the course of a million years. Jets of energy and particles flowing forwards at the speed of light are a common feature of the enormous black holes in the heart of the Milky Way.
‘We already knew that the enormous black holes at the centre of other galaxies produce huge amounts of energy, but this discovery proves that something similar is happening around the much smaller black holes close by’, says UvA-astronomer Elena Gallo, lead author of the scientific publication in Nature. ‘It is remarkable that a star is capable of producing energy using completely different mechanisms, even after it has died and become a black hole.’
100,000 times more energy than radiated by the sun
The latest and detailed radio observations of the black hole Cygnus X-1 show a ring of radio radiation around a bubble in the intergalactic gas close by, which is the result of the intense interaction of the jet with the thin gas of the intergalactic medium around Cygnus X-1.
The jet which has created this bubble is estimated to posses more than 100,000 times more energy than the amount of energy radiated by the sun. This enormous source of energy is nevertheless visible only directly because of its influence on the gas surrounding the black hole.
’The importance of this result is that it shows that black holes such as Cygnus X1, of which there are probably millions in our galaxy alone, do not swallow all matter and energy from their surroundings but redirect a large portion of it back into space’, says Prof. Rob Fender of the University of Southampton, second author of the paper.
The bubble was discovered through radio-astronomical observations with ASTRON’s Westerbork Synthese Radio Telescope (WSRT). The observations centred on the well known roentgen double star Cygnus X1 which is known to be close to a black hole. The bubble was also perceived in optical observations of the Anglo-Dutch 2.5m Isaac Newton Telescope on the Canary Islands.
Formation of the bubble
The bubble is approximately ten light years across and is predicted to be increasing with a speed of around a hundred kilometers per second. The bubble seems to have been formed by a jet, a powerful stream of energy and matter originating in the black hole, in the course of a million years. Jets of energy and particles flowing forwards at the speed of light are a common feature of the enormous black holes in the heart of the Milky Way.
‘We already knew that the enormous black holes at the centre of other galaxies produce huge amounts of energy, but this discovery proves that something similar is happening around the much smaller black holes close by’, says UvA-astronomer Elena Gallo, lead author of the scientific publication in Nature. ‘It is remarkable that a star is capable of producing energy using completely different mechanisms, even after it has died and become a black hole.’
100,000 times more energy than radiated by the sun
The latest and detailed radio observations of the black hole Cygnus X-1 show a ring of radio radiation around a bubble in the intergalactic gas close by, which is the result of the intense interaction of the jet with the thin gas of the intergalactic medium around Cygnus X-1.
The jet which has created this bubble is estimated to posses more than 100,000 times more energy than the amount of energy radiated by the sun. This enormous source of energy is nevertheless visible only directly because of its influence on the gas surrounding the black hole.
’The importance of this result is that it shows that black holes such as Cygnus X1, of which there are probably millions in our galaxy alone, do not swallow all matter and energy from their surroundings but redirect a large portion of it back into space’, says Prof. Rob Fender of the University of Southampton, second author of the paper.