Astronomers have identified a supermassive black hole that absorbs the equivalent of one sun per day and is located at the heart of the most luminous quasar ever observed, according to a study published in Nature.
• Also read: Space: A 30-year-old satellite is expected to fall to Earth on Wednesday
• Also read: Japanese probe launched to examine space debris
“We have discovered the fastest growing black hole to date. It has a mass of 17 billion suns and “eats” just over one sun per day,” said Christian Wolf, an astronomer at the Australian National University (ANU) and lead author of the study, in a statement to the European Southern Observatory (ESO).
Invisible by definition, a supermassive black hole's activity illuminates the core of the galaxy that hosts it. This nucleus is called a quasar and the one observed by ESO's Very Large Telescope (VLT in Chile) is, according to Christian Wolf, “the most luminous object in the known universe”.
Its light took 12 billion years to reach the VLT instruments, allowing its existence to be dated to the very beginning of the universe – 13.8 billion years old.
The light from J0529-4351, as it was called, was discovered in the 1980s, recalls the study published on Monday. But an automatic analysis of data from the Gaia satellite, which maps the galaxy, had compared it to a very bright star.
Researchers using the Siding Spring Observatory in Australia and then the VLT's X-Shooter instrument actually identified it as a quasar last year.
The supermassive black hole that hosts it attracts a colossal amount of matter, which is accelerated to no lower speeds and emits light equivalent to that of more than 500 billion suns, says the ESO press release.
The existence of such a massive and luminous object in the early universe “is difficult to explain,” says the study, which recalls the discovery of similar quasars in recent years.
Their existence always requires the rapid growth of a supermassive black hole, which the theory still has difficulty describing.
A black hole is said to be formed by the explosion of a star at the end of its life, whose core then collapses. It can grow by feeding on the surrounding matter and being attracted to its gravitational field.
Scientists wonder about the process that allows a black hole in the early universe to become supermassive in a relatively short period of time.