Spinning black holes are ‘ultimate cosmic batteries’
London, Jan 27 : In a new research, scientists have determined that spinning black holes are the ultimate cosmic batteries, as it seems they can store and unleash the energy of billions of supernovae, with potentially devastating consequences for their host galaxies.
Many of the supermassive black holes that lurk at the centre of galaxies fire out powerful plasma jets that extend for millions of light years.
Though the details of how these jets are produced remain murky, there seems to be only two plausible power sources: one is matter falling onto the black hole, which can't explain all the cases.
The other source is the black hole's stored rotational energy.
Calculations suggest it should be possible for jets to siphon off energy at the expense of the black hole's rotation as long as magnetic fields are present to connect the black hole to any matter nearby.
Persuasive evidence for this has been lacking.
Now, according to a report in New Scientist, a team led by Brian McNamara of the University of Waterloo, Canada, has found what may be the strongest evidence yet for jets powered by black hole rotation.
It comes from a galaxy called MS0735.6+7421, about 2.6 billion light years from Earth.
In 2005, data on this galaxy from the Chandra X-ray Observatory revealed the biggest outpouring of energy ever identified from black hole jets.
Based on cavities the jets have apparently punched through the surrounding gas, the team calculates that in the past 100 million years or so, jets have put out 1055 joules, billions of times the energy of a supernova.
It would have been next to impossible for matter falling into the black hole to power these jets.
"It would have had to essentially vacuum all of the matter that was in that galaxy down into the black hole in a period of 100 million years, and we know nature doesn't work that way," McNamara said. "Accretion of matter onto a black hole is very inefficient," he added.
That leaves black hole spin as the only other energy source.
The black hole could have been set spinning in the first place by matter falling onto it much earlier in its lifetime or in the course of a merger with another black hole.
A huge amount of energy can be stored in black hole spin, and if it gets released again in the form of jets, it could have profound effects. (ANI)