Durham scientists working with NASA have discovered supermassive black holes are hidden behind clouds of gas and dust close to our own galaxy.
Scientists believe these huge black holes lurk at the centres of most big galaxies, but many are hidden from the view of most telescopes.
Now astronomers at Durham University have confirmed that two of these destructive giants have been lurking behind thick layers of gas and dust at the heart of galaxies near the Milky Way.
Working with experts at Southhampton University and using NuSTAR, a space-based telescope belonging to NASA, they followed a trail of high-energy X-ray emissions generated by the black holes as they feed on surrounding material.
One of them was found at the centre of the NGC 1448 spiral galaxy, and closely examined in a study led by Ady Annuar, a postgraduate researcher in Durham’s Department of Physics.
NGC 1448 is one of the nearest large galaxies to our Milky Way at 38 million light years away. It’s close to us in terms of the wider universe, but since one light year is about six trillion miles, the black hole is still fairly far away.
But since gas and dust kept this active black hole from our sight, it’s possible there could be others still to be found, perhaps even closer to home.
Ady Annuar said: “These black holes are relatively close to the Milky Way, but they have remained hidden from us until now.
“They’re like monsters hiding under your bed.
“Their recent discoveries certainly call out the question of how many other supermassive black holes we are still missing, even in our nearby Universe.”
The other black hole was studied by scientists in Southampton, in a galaxy called IC 3639, 170 million light years away.
Researchers confirmed that the areas around both black holes, described as the “central engine” or nucleus of the galaxies, are incredibly bright, but a doughnut-shaped region of thick gas and dust obscures them from view.
These “active galactic nuclei” are so bright because particles in the regions around the black hole get very hot and emit radiation.
In order to spot the black holes, scientists had to watch for the reflected X-rays of these particles escaping from behind the dust.