2024-01-13 21:13:43
Astronomers 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 idea, which challenges previous theories, could significantly advance our understanding of the influence of black holes on the evolution of galaxies.
Cardiff astronomers, along with international partners, have revealed a new method to study how black holes feast.
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 their varying rates of consumption of surrounding galactic materials, such as gas clouds, dust, and plasma.
Rethinking the behavior of black holes
Led by scientists at Cardiff University, the team says this process is not predicted by our current understanding of how black holes feed.
Currently considered to be intrinsically different depending on their appetites, active black holes are characterized by the arrangement of their core and the way in which they draw in galactic matter.
However, the team discovered that these black holes may have more similarities than previously thought. Their discoveries, Published in Monthly notices of the Royal Astronomical Society: letterscould offer new insights into how galaxies evolve.
Surprising observations and new insights
Lead author Dr Ilaria Ruffa, a postdoctoral research associate at the School of Physics and Astronomy at Cardiff University, said: “The microwave and X-ray glow that we detect in Regions around these black holes appear to be directly linked to their mass and to come from plasma flows falling there in a disorderly manner. This is the case in both systems that have enormous appetites, eating almost an entire star like our Sun per year, and those with lesser appetites, eating the same amount of material over 10 million years. This was very surprising because we previously thought that such flows should only occur in systems eating at a low rate, whereas in those with a huge appetite the black hole should be fed by a more orderly and constant flow of matter. (usually called an “accretion disk”).
The team made the discovery by studying the link between cold gas around active black holes and how they are powered 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 detect could actually come from these plasma flows in all types of active black holes, thus changing our view of how these systems consume matter. and become the cosmic monsters 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 impact on the evolution of galaxies across the Universe.
Co-author Dr Timothy Davis, reader at the School of Physics and Astronomy at Cardiff University, added: “Galaxies care a lot about the black holes that exist in their cores. And they probably shouldn’t, because while we always think of black holes as supermassive beasts that consume everything around them, they’re actually very small and light in the context of an entire galaxy. “And yet they have a mysterious non-gravitational influence on matter tens of thousands of light years away. This is a question that we have been intrigued by as astronomers for many years.
“Measuring the masses of black holes and comparing these to the properties of their host galaxies is the best way to begin to understand why this mystery persists. Our new method opens a new window on this problem and, with the next generation of instruments, will allow us to explore it in depth over cosmic time.
Made up of researchers from Cardiff Hub for Astrophysics Research and Technology (CHART) and international partners from across Europe, Canada and Japan, the team plans to further test their results as part of a new project “multi-wavelength observations of nuclear dark object emission regions” (WONDER) led by Dr. Ruffa.
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