News

Astronomers identify ‘food source’ that fuels supermassive black holes

The researchers said their observations add ‘a fundamental piece to the puzzle’ on how the giant cosmic structures formed.
The researchers said their observations add ‘a fundamental piece to the puzzle’ on how the giant cosmic structures formed. The researchers said their observations add ‘a fundamental piece to the puzzle’ on how the giant cosmic structures formed.

Astronomers believe they have uncovered the mystery as to how ancient black holes grew quickly to become supermassive objects around 12 billion years ago.

A team of international researchers say they have identified the “food source” that fuels black holes, the dense matter at the heart of galaxies.

In a study published in The Astrophysical Journal, the team report that the so-called “black hole food”, made up of reservoirs of interstellar gas and dust that surrounds galaxies, allowed these cosmic monsters to grow rapidly at a time when the universe was still young.

They believe their findings add “a fundamental piece to the puzzle” on how cosmic structures, featuring galaxy clusters and voids, formed.

Dr Emanuele Paolo Farina, of the Max Planck Institute for Astronomy in Germany, said: “The presence of these early monsters, with masses several billion times the mass of our Sun, is a big mystery.

“We are now able to demonstrate, for the first time, that primordial galaxies do have enough food in their environments to sustain both the growth of supermassive black holes and vigorous star formation.”

One of the gas halos newly observed with the MUSE instrument on ESO’s Very Large Telescope.
One of the gas halos newly observed with the MUSE instrument on ESO’s Very Large Telescope. One of the gas halos newly observed with the Muse instrument (Farina et al/ESO/PA) (ESO/Farina et al.; ALMA (ESO/NAO)

The astronomers used the European Southern Observatory’s Very Large Telescope, including an on-board instrument known as Muse, to gather data on the ancient black holes.

They surveyed 31 quasars – extremely bright nuclei in active galaxies.

The astronomers found 12 of those quasars were surrounded by enormous reservoirs made up of cool, dense hydrogen gas.

These gas halos were tightly bound to the galaxies which, according to the researchers, provided “the perfect food source” to sustain the growth of supermassive black holes.

Dr Farina said: “In a matter of a few hours per target, we were able to delve into the surroundings of the most massive and voracious black holes present in the young universe.

“While quasars are bright, the gas reservoirs around them are much harder to observe.

“But Muse could detect the faint glow of the hydrogen gas in the halos, allowing astronomers to finally reveal the food stashes that power supermassive black holes in the early universe.”