New research at Sheffield University has solved a long-standing mystery surrounding the evolution of galaxies, deepening understanding of the future of the Milky Way.
The supermassive black holes in the cores of some galaxies drive massive outflows of molecular hydrogen gas. As a result, most of the cold gas is expelled from the galaxies - and since it is required to form new stars, this directly affects the galaxies’ evolution.
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.
A study led by Sheffield astronomers provides the first direct evidence that the molecular outflows are accelerated by energetic jets of electrons that are moving at close to the speed of light.
Using a telescope in Chile, researchers found that the gas is moving at extraordinary speeds – one million kilometers per hour.
The findings help further understand the eventual fate of our own galaxy, the Milky Way, which will collide with neighbouring galaxy Andromeda in about five billion years.