Distant black hole spotted shredding a star
Black holes may emit energy in proportion to the amount of stellar material they consume
A black hole situated more than a billion light years away has torn up and devoured a star, allowing astronomers to gain a deeper insight into the workings of such celestial objects. Scientists have been studying emissions from the supermassive black hole and they have found a proportional link between the X-rays that are produced by stellar material falling into the hole and the jet of energy that is emitted. It gives clues as to how black holes devour matter and regulate the growth of galaxies.
The findings relate to radio signals picked up in November 2014 from 300 million light years away. Scientists found that the signals matched closely with X-ray emissions produced from a flare 13 days earlier. Such radio echoes are considered to be more than coincidence, indicating some kind of burp. It suggests black hole jets are powered by the accretion rates and it is the first time scientists have been able to observe it from a single event.
“This is telling us the black hole feeding rate is controlling the strength of the jet it produces,” says Dheeraj Pasham, a postdoc at MIT's Kavli Institute. “A well-fed black hole produces a strong jet, while a malnourished black hole produces a weak jet or no jet at all. This is the first time we’ve seen a jet that’s controlled by a feeding supermassive black hole.”
The results will help astronomers work out the physics of jet behaviour, which is essential in modelling the evolution of galaxies. “If the rate at which the black hole is feeding is proportional to the rate at which it’s pumping out energy, and if that really works for every black hole, it’s a simple prescription you can use in simulations of galaxy evolution,” says Pasham.