ALMA Telescope in the Atacama desert, Chile. Image: Sangku Kim/ESO
Marc Sarzi, head of research at the Armagh Observatory and Planetarium, was part of a black hole study that could help us better understand the evolution of galaxies.
The head of research at the Armagh Observatory and Planetarium in Northern Ireland was part of a study that has discovered a new way to probe how black holes – the most mysterious objects in our universe – devour objects around it.
Marc Sarzi was part of an international team of scientists led by Cardiff University that discovered how a sample of black holes at the centre of 136 galaxies shone in microwave and X-ray light in the same way, regardless of their appetite for surrounding galactic matter.
Published in the Monthly Notices of the Royal Astronomical Society: Letters this week, the findings are expected to offer new information about the evolution of galaxies.
“The microwave and X-ray glow we detect from the regions around these black holes seems to directly relate to their mass and to originate from extremely hot puffy streams of gas falling into them,” explained Dr Ilaria Ruffa, lead author and postdoctoral researcher at Cardiff University.
“This is the case in both systems that have huge appetites that are eating nearly an entire star like our sun per year, and those with lesser appetites which are eating the same amount of material over 10m years.”
Ruffa said this was a surprising discovery because it was previously thought that such streams should occur “only in systems eating at low rates”.
“Whereas in those with huge appetites, the gas feeding the black hole should collapse into a disc, usually called ‘the accretion disc’, allowing the system to be fed in a more ordered manner.
“Our study suggests that the microwave light we detect may actually come from these streams of plasma in all types of active black holes, changing our view on how these systems consume matter and grow to be the cosmic monsters we see today.”
According to the study, the process is not something that has been predicted by current understandings of how black holes consume objects close to it, such as clouds of gas, dust and sometimes even neutron stars.
“Black holes are always a fascinating subject for the general public, including visitors of science centres and planetariums around the world,” said Sarzi, who had been at the Armagh Observatory and Planetarium since 2018.
“This work adds an interesting element as it shows how black holes of widely different mass all work in the same way, like the engines of cars large and small.”
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