Recent discoveries indicate that the universe may harbour significantly more feeding supermassive black holes than previously estimated. These colossal entities, each with a mass ranging from millions to billions of times that of the Sun, are believed to be concealed by dense veils of gas and dust. This obscuration, researchers suggest, could hide nearly 30 percent to 50 percent of these actively feeding black holes, which remain undetected by standard telescopes due to their shrouded surroundings.
Obscuration from Supermassive Black Holes
The study, detailed in The Astrophysical Journal, examined the obscuration caused by material encircling supermassive black holes. As per a report by Space.com, this gas and dust often form a donut-like structure, obscuring their bright central regions from direct observation. Researchers working on the NuLANDS (NuSTAR Local AGN N H Distribution Survey) project employed infrared data from NASA’s NuSTAR spacecraft to locate these hidden cosmic giants. Peter Boorman, a researcher from the California Institute of Technology, highlighted during the American Astronomical Society meeting that the obscured black holes play a critical role in galaxy evolution.
According to reports, Boorman remarked during the presentation that black holes influence their host galaxies profoundly despite their relatively small size
Effects on Star Formation and Galactic Evolution
Jets of material emitted by these feeding black holes, travelling at speeds of up to one-third the speed of light, have been identified as disruptive forces in their host galaxies. By expelling essential gas and dust, these jets can inhibit or even halt star formation. Observations made using infrared surveys revealed that black holes hidden behind dust and gas emit detectable radiation, allowing their presence to be inferred.
Poshak Gandhi, a researcher from the University of Southampton, commented in an official press release from the university that many of these black holes were identified only through their re-emitted infrared radiation. These findings, researchers noted, are pivotal in understanding how black holes grow and influence the galaxies they inhabit, providing a deeper perspective on the mechanisms driving galactic evolution.
