Astronomers have made a groundbreaking discovery, revealing that approximately 35% of supermassive black holes in the universe are concealed from view. Using data from NASA’s Infrared Astronomical Satellite (IRAS) and the Nuclear Spectroscopic Telescope Array (NuSTAR), scientists identified hundreds of probable hidden black holes.
The combined infrared and high-energy X-ray observations allowed researchers to peer through obscuring material and confirm the existence of numerous previously overlooked black holes. Professor Poshak Gandhi, co-author of the study, said that many more supermassive black holes are lurking in plain sight, hiding behind dust and gas rendering them invisible to normal telescopes.
The discovery has significant implications for understanding galaxy evolution. Supermassive black holes play a crucial role in feeding their host galaxies, affecting star formation rates through feedback mechanisms. If too much material falls toward a black hole, it can produce galaxy-wide winds that snuff out star formation. This process can slow down or halt the formation of new stars in the surrounding galaxy.
The researchers used NuSTAR to detect high-energy X-rays capable of penetrating thick gas clouds, and IRAS to analyze infrared emissions detected by the satellite. By analyzing these observations, they could identify the heat signatures of obscuring clouds around the black holes. The study’s findings suggest that supermassive black holes can limit a galaxy’s size by drawing it toward a gravitational center or consuming vast quantities of star-forming dust.
The discovery is particularly notable due to the use of legacy data from IRAS, which was operational over 40 years ago. The researchers’ success demonstrates the value of using archival telescopes with different wavelengths of light to study celestial objects.
Source: https://www.jpost.com/science/science-around-the-world/article-838303