A group of astronomers headed by Prof Clive Tadhunter from the the University of Sheffield has discovered that the central supermassive black hole of the Seyfert galaxy IC 5063 blasts the warm molecular hydrogen out at high velocity – about 600 km per second – relative to the galaxy disk.
This image shows the nearby Seyfert galaxy IC 5063. Image credit: Sky-map.org.
Supermassive black holes in the cores of some galaxies drive massive outflows of molecular hydrogen. As a result, most of the cold gas is expelled from the galaxies.
Since cold gas is required to form new stars, this directly affects the evolution of galaxies.
The outflows are now a key ingredient in theoretical models of the evolution of galaxies, but it has long been a mystery as to how they are accelerated.
According to Prof Tadhunter’s team, these molecular outflows are accelerated by energetic jets of electrons that are moving at close to the speed of light.
To reach this conclusion, they observed the galaxy IC 5063 using ESO’s Very Large Telescope in Chile.
“The findings help astronomers further understand the eventual fate of our own galaxy, the Milky Way, which will collide with neighbouring galaxy Andromeda in about 5 billion years,” said Prof Tadhunter, who is the first author of a paper published in the journal Nature.
“As a result of this collision, gas will become concentrated at the center of the system, fuelling its supermassive black hole, and potentially leading to the formation of jets that will then eject the remaining gas from the galaxy – just as we already observe in IC 5063.”
He added: “much of the gas in the outflows is in the form of molecular hydrogen, which is fragile in the sense that it is destroyed at relatively low energies.”
“It is extraordinary that the molecular gas can survive being accelerated by jets of electrons moving at close to the speed of light.”
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C. Tadhunter et al. Jet acceleration of the fast molecular outflows in the Seyfert galaxy IC 5063. Nature, published online July 06, 2014; doi: 10.1038/nature13520
