The most luminous galaxy ever discovered is cannibalising at least three of its smaller neighbours, study finds

The galaxy radiates at 350 trillion times the luminosity of the Sun

The most luminous galaxy ever discovered in the universe is stealing a huge amount of mass from its three small neighbours, a new study by scientists at NASA's Jet Propulsion Laboratory and Universidad Diego Portales in Chile has revealed.

The galaxy, dubbed W2246-0526 (complete name WISE J224607.55-052634.9), is the most luminous known galaxy in the universe, and was discovered in 2015 by NASA's space-based Wide-field Infrared Survey Explorer.

According to NASA, this galaxy is not the largest or most massive known galaxy in the universe, but it is definitely the most luminous galaxy, radiating at 350 trillion times the luminosity of the Sun. It would appear as the brightest galaxy if all galaxies are put at same distance from us.

In the new study, astronomers observed W2246-0526 using the Atacama Large Millimeter/submillimetre Array (ALMA) in Chile and found the galaxy to be pulling distinct trails of dust from three smaller neighbouring galaxies.

"We knew from previous data that there were three companion galaxies, but there was no evidence of interactions between these neighbors and the central source," said Tanio Diaz-Santos of the Universidad Diego Portales in Santiago, Chile, the lead author of the study.

"We weren't looking for cannibalistic behaviour and weren't expecting it, but this deep dive with the ALMA observatory makes it very clear."

According to scientists, W2246-0526 falls under the category of hot, dust-obscured galaxies (Hot DOG) - a special type of particularly luminous quasars. Most quasars are believed to get some of their fuel from external sources.

According to scientists, this is not the first instance of galactic cannibalism behaviour being observed by astronomers. In the past, several galaxies merging with or accreting matter from their neighbours have been spotted by scientists. However, W2246-0526 is the most distant galaxy that has been seen to be accreting material from a number of sources.

Another notable feature of W2246-0526 is that the light originating from it takes nearly 12.4 billion years to reach to Earth, which means astronomers are actually observing this galaxy as it was when the universe was just one-tenth of its present age.

The findings of the study are published in journal Science.