Cardiff astronomers working with international partners have discovered a new way to analyze active black holes, revealing that their microwave and X-ray emissions are similar at different consumption rates. This insight challenges previous theories and may significantly advance our understanding of the impact of black holes on galaxy evolution.
They observed a sample of active black holes located at the centers of 136 galaxies and found that they emitted consistent patterns of microwave and X-ray light, independent of their different rates of consumption of surrounding galactic material, such as gas clouds, dust and plasma.
The team, led by scientists at Cardiff University, said this process was not predicted by our current understanding of how black holes feed.
Current understanding is that active black holes differ fundamentally by their appetites, which are characterized by the layout of the black hole's core and the way it sucks in galactic material. However, the team found that these black holes may have more similarities than previously thought. Their findings were published in the Monthly Notices of the Royal Astronomical Society.
Lead author Dr Ilaria Ruffa, a postdoctoral research associate at Cardiff University's School of Physics and Astronomy, said: "The microwave and X-ray glow we detect from the regions surrounding these black holes appear to be directly related to the black hole's mass, and originate from the chaotic flow of plasma falling into the black hole. This occurs both in systems with such huge appetites that they devour them almost every year. Devouring a star like the Sun also occurs in systems with smaller appetites, which gobble up the same amount of material over a period of 10 million years. This is surprising because we previously thought that this flow of material should only occur in systems with large appetites, and that in systems with large appetites, the black hole should feed through a more orderly and constant flow of matter, often called an "accretion disk."
The research team discovered the connection between the cold gas around the active black hole and how the black hole obtains fuel in a WISDOM sample of 35 nearby galaxies captured by the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile.
Dr Ruffa added: "Our study shows that the microwave light we detect may actually come from these plasma streams in all types of active black holes, changing our view of how these systems consume matter and grow into the cosmic monsters we see today."
The correlation observed by the team also provides a new way to estimate the mass of a black hole - something astronomers believe is crucial to understanding the impact of black holes on the evolution of galaxies throughout the universe.
Dr. Timothy Davis, co-author of the paper from the School of Physics and Astronomy at Cardiff University, added: "Although we always think of black holes as supermassive behemoths that swallow everything around them, they are indeed very small and very light in the entire galaxy. However, they have a mysterious non-gravitational pull on matter tens of thousands of light-years away. Impact. This is a question that has puzzled us astronomers for many years. Measuring the masses of black holes, and comparing those masses to the properties of their host galaxies, is the best way to begin to understand why this mystery exists, and with the next generation of instruments we will be able to explore it deeply in cosmic time."
Compiled from /ScitechDaily