Recent research indicates that the universe may harbor significantly more supermassive black holes than previously estimated, with potential undercounting of 30 to 50 percent of these massive entities.
These black holes, which can possess masses millions to billions of times that of the Sun, often remain obscured by the galactic gas and dust that fuel their growth. Peter Boorman, a researcher at the California Institute of Technology, presented these findings at the 245th meeting of the American Astronomical Society in Maryland.
Boorman noted that the size ratio of a supermassive black hole to its host galaxy resembles a pea compared to Earth. Despite this vast size difference, these black holes can significantly influence their host galaxies, potentially hindering star formation through the expulsion of gas and dust via high-speed astrophysical jets.
The phenomenon of obscuration, wherein feeding black holes are concealed by surrounding material, complicates their detection. Previous studies estimated that 15 percent of these black holes might be hidden due to this effect.
Utilizing infrared data from NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) as part of the NuLANDS survey, researchers were able to gather evidence of black holes feeding on nearby matter. This data revealed that the surrounding gas, heated by the black holes, emits intense infrared light, making them detectable despite their inherent darkness.
Poshak Gandhi from Southampton University emphasized that many more black holes are likely present, hidden behind dust and gas, which renders them invisible to conventional telescopes. The implications of discovering these hidden black holes extend to a deeper understanding of galaxy evolution and the growth mechanisms of supermassive black holes.
Gandhi stated that the absence of black holes could lead to larger galaxies, and Boorman remarked that if humans could detect X-rays, the night sky would be filled with visible accreting supermassive black holes.