Astronomers have discovered a new method for analyzing active black holes, finding that their microwave and X-ray emissions are similar at different consumption rates. This idea, which challenges previous theories, could significantly improve our understanding of the influence of black holes on the evolution of galaxies.
Cardiff astronomers, along with international partners, have unveiled a new method to study how black holes feed.
An international team of astronomers has discovered a completely new method for studying the behavior of active black holes.
They observed a sample of active black holes located at the centers of 136 galaxies and found a consistent pattern in their emission of microwaves and X-rays, regardless of the varying rate of consumption of surrounding galactic materials such as gas clouds and dust and plasma.
Rethinking the behavior of black holes
The team, led by scientists at Cardiff University, says this process is not predicted by our current understanding of black hole feeding.
It is currently assumed that active black holes are fundamentally different depending on their appetites. They are distinguished by the arrangement of their core and the way they suck in galactic matter.
However, the team discovered that these black holes may have more similarities than previously thought. Your discoveries, Published in the Monthly Notices of the Royal Astronomical Society: Letters could offer new insights into the evolution of galaxies.
Surprising observations and new insights
The lead author Dr. Ilaria Ruffa, a postdoctoral researcher at Cardiff University's School of Physics and Astronomy, said: “The microwave and X-ray light we detect in regions around these black holes appears to be directly related to their mass,” coming from disorderly falling plasma streams there. This is the case for both systems, which have enormous appetites, eating almost an entire star like our Sun per year, and systems with smaller appetites, which eat the same amount of material over 10 million years. This was very surprising, as we previously thought that such flows should only occur in systems that feed slowly, whereas in systems with a large appetite the black hole should be fed by a more orderly and constant flow of matter. accretion disk).
The team made the discovery by studying the connection between cold gas around active black holes and their energy supply in the WISDOM sample of 35 nearby galaxies captured by the Atacama Large Millimeter/submillimeter Array (ALMA) of telescopes in Chile.
Dr. Ruffa added: “Our study suggests that the microwave light we are detecting may actually come from these plasma flows in all types of active black holes, changing our view of how these systems consume matter and become the cosmic monsters that we see today.” »
Implications for estimating black hole masses
The correlations observed by the team also provide a new method for estimating the mass of black holes – which astronomers say is key to understanding their influence on the evolution of galaxies across the universe.
Co-author Dr. Timothy Davis, senior lecturer at Cardiff University's School of Physics and Astronomy, added: “Galaxies care deeply about the black holes that exist in their cores. And they probably shouldn't, because while we always think of black holes as supermassive entities that devour everything around them, in the context of an entire galaxy, they are actually very small and light. “And yet they have a mysterious, non-gravitational influence on matter tens of thousands of light-years away. This question has puzzled us as astronomers for many years.
“Measuring the masses of black holes and comparing them with the properties of their host galaxies is the best way to understand why this mystery persists. Our new method opens a new window on this problem and will allow us to study it in depth across cosmic time with the next generation of instruments.
Consisting of researchers from The team plans to further test the results from the Cardiff Hub for Astrophysics Research and Technology (CHART) and international partners from across Europe, Canada and Japan new project “Multi-wavelength observations of nuclear emission regions of dark objects” (WONDER) led by Dr. Ruffa.