Galaxies supermassive black holes
This is an image of galaxy SDSS J1354 1327 (lower center) and its companion galaxy SDSS J1354 1328 (upper right). NASA/ESA/J. Comerford

In a unique observation, astronomers have witnessed a supermassive black hole in a distant galaxy snacking on gas and then burping it up - twice.

The black hole in question, known as J1354, is situated about 800 million light years from Earth and was studied using data captured by Nasa's Hubble Space Telescope, the Chandra X-ray observatory, the W. M. Keck Observatory and the Apache Point Observatory.

Investigating J1354, Chandra detected a supermassive black hole, millions or billions of times more massive than the Sun, at the centre of the galaxy, embedded in a thick cloud of gas and dust.

The findings show that, millions of years ago, the black hole appears to have consumed large amounts of gas before ejecting huge jets of high energy particles in a cosmic 'burp'. This release of material eventually stopped before resuming again around 100,000 years later.

While astronomers have predicted this type of event before, it has never been observed directly.

"We are seeing this object feast, burp, and nap, and then feast and burp once again, which theory had predicted," said Julie Comerford, leader of the study from the University of Colorado Boulder. "Fortunately, we happened to observe this galaxy at a time when we could clearly see evidence for both events."

The explanation for these gas-feeding events lies in a companion galaxy, which had previously collided with J1354. The researchers suggest that material from the companion galaxy gravitated towards the centre of J1354, providing it with huge amounts of extra material to eat.

The supermassive black hole at the centre of the Milky Way has had at least one 'burp' that we know about, with astronomers detecting indirect signs of an event in 2010.

"Our galaxy's supermassive black hole is now napping after a big meal, just like J1354's black hole has in the past. So, we also expect our massive black hole to feast again, just as J1354's has."