A new study published in the Astrophysical Journal has provided a better estimate of the ratio of hidden to unhidden supermassive black holes in the universe. Using multiple NASA telescopes, scientists were able to search for these massive objects and find that about 35% are heavily obscured by gas and dust clouds. This is significantly higher than previous studies which found less than 15%.
The researchers used a combination of X-ray and infrared observations to identify edge-on and face-on black holes. The Infrared Astronomical Satellite (IRAS), launched in 1983, was able to detect the infrared emissions from the surrounding clouds of gas and dust. Ground-based telescopes were then used to separate these galaxies from the hidden black holes.
The study’s findings support the hypothesis that massive black holes grow by consuming material, which is then surrounded by thick clouds and potentially obscured. These black holes also influence galaxy growth by impacting how galaxies evolve.
According to Poshak Gandhi, a coauthor on the study, “If we didn’t have black holes, galaxies would be much larger.” This highlights the significant role that supermassive black holes play in shaping the universe.
Source: https://www.nasa.gov/universe/how-many-black-holes-are-hiding-nasa-study-homes-in-on-answer