Astronomers have detected a supermassive black hole 12 billion light-years away at the centre of a galaxy, officially named GS-10578 but nicknamed ‘Pablo’s Galaxy’, which is starving it to death. Using the NASA/ESA James Webb Space Telescope, they observed the galaxy, roughly the size of our own Milky Way Galaxy, in the early universe, about two billion years after the Big Bang.
Like most large galaxies, it has a supermassive black hole at its centre. But this galaxy is essentially ‘dead’ as it has stopped forming new stars. Their discovery confirms that supermassive black holes can indeed starve host galaxies of the fuel needed to form new stars. Pablo’s Galaxy is massive for such an early period in the universe: its total mass is about 200 billion times the mass of our Sun, and most of its stars formed between 12.5 and 11.5 billion years ago. The researchers detected that Pablo’s Galaxy is expelling large amounts of gas at speeds of about 1,000 kilometres per second — fast enough to escape the galaxy’s gravitational pull. The mass of gas ejected is greater than that required to form new stars. These fast-moving winds are being ‘pushed’ out of the galaxy by the black hole.
The galaxy has fast outflowing winds of hot gas, but these gas clouds are tenuous and have little mass. Webb detected the presence of a new wind component, which could not be seen with earlier telescopes. This gas is colder, which means it’s denser and crucially does not emit any light. Webb, with its superior sensitivity, can see these dark gas clouds because they block some of the light from the galaxy behind them.