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It seems that there are more black holes in the universe than we can imagine, according to a team of scientists who have just discovered a number of supermassive supermassive ones.
The findings could help scientists understand how massive black holes grow — billions of the mass of our Sun — and explain the important role black holes play in galactic evolution.
Black holes have such a strong gravitational pull that even light cannot escape beyond a certain point—the end of a black hole. But outside of the event, the area around the black hole is very bright, because it is filled with superheated gas and dust called the accretion disk.
These objects sometimes block the light that astronomers would be able to see. The team found that about 35% of the supermassive black holes they studied are hidden by their surrounding gas and dust. These findings suggest that the number of hidden black holes is greater than previously believed, as earlier studies showed that about 15% of supermassive black holes were deeply hidden. A group study was printed last month in The Astrophysical Journal.
The team reached its conclusions based on data from NASA’s Infrared Astronomical Satellite (IRAS) and Nuclear Spectroscopic Telescope Array (NuSTAR) X-ray observatories. IRAS captures infrared light (as its name suggests), and the infrared emission from black hole accretion disks indicates whether the black hole is facing the satellite directly, or whether its edge is pointing toward the instrument. After identifying a group of hundreds of early targets using IRAS, the research team used NuSTAR to confirm the edges—meaning hidden black holes—by measuring its X-ray emission.
“If we didn’t have black holes, galaxies would be expanding,” said study co-author Poshak Gandhi, an astrophysicist at the University of Southampton, in NASA’s Jet Propulsion Laboratory. to release. “So if we didn’t have a super black hole in our Milky Way galaxy, there would be more stars in the sky. This is just one example of how black holes can affect the evolution of a galaxy.”
Also, the energy of black holes can extend far beyond the galaxies that host them. Last year, a group of astronomers found out the most famous black hole jets-streams of particles exiting the object at nearly the speed of light. The plane is called Porphyrion, after the giant in Greek mythology, and is at least 140 times the diameter of the Milky Way galaxy.
Black holes are an important engine of galaxy evolution, but even these massive objects can elude human detection. Recent research has revealed just how invisible these hidden black holes are—and suggests that there are more giant juggernauts than we know.
