NASA astronomers have zeroed in on the number of hidden supermassive black holes

There are probably more supermassive black holes in the universe than we can see, according to a team of scientists who have obtained new estimates of the number of giants hidden from view.

The finding could help scientists understand how supermassive black holes grow to billions of times the mass of the Sun and clarify the important role black holes play in galactic evolution.

Black holes have such strong gravitational fields that even light cannot escape from their vicinity beyond a point behind the black hole’s event horizon. But beyond the event horizon, the black hole’s environment is very bright because it is filled with a pancake of superheated gas and dust known as an accretion disk.

This material sometimes blocks the light that astronomical observatories would otherwise see. The team found that about 35% of the supermassive black holes they studied are covered by surrounding gas and dust. This finding suggests that the number of hidden black holes is greater than previously thought, as previous searches suggested that about 15% of supermassive black holes are so hidden. It was a group study has been published last month The Astrophysical Journal.

The team came to this conclusion based on data from NASA’s Infrared Astronomy Satellite (IRAS) and the Nuclear Spectroscopic Telescope Array (NuSTAR) X-ray observatory. IRAS receives infrared light (as the name suggests), and the infrared emissions from the black hole’s accretion discs indicate whether the black hole is directly facing the satellite or has its edge pointed at the instrument. After identifying a group of hundreds of initial targets using IRAS, the research team used NuSTAR to confirm black holes in the outer reaches, i.e. in obscurity, based on their X-ray emissions.

“Galaxies would be bigger if we didn’t have black holes,” said study co-author Poshak Gandhi, an astrophysicist at the University of Southampton at NASA’s Jet Propulsion Laboratory. release. “So if our Milky Way galaxy didn’t have a supermassive black hole, there would be many more stars in the sky. This is just one example of how black holes can affect galaxy evolution.”

Furthermore, the influence of black holes can extend far beyond the galaxies in which they reside. Last year, a group of astrophysicists identified the most famous black hole jets— streams of particles leaving an object at approximately the speed of light. The planes are called Porphyrion, after a giant from Greek mythology, and are at least 140 times the width of the Milky Way galaxy.

Black holes are important engines of galactic evolution, but even these extremely massive objects can elude human detection. Recent research has shown how these hidden black holes have been hidden from view and suggests that there are more space monsters than we know.