Scientists recently found a supermassive black hole that’s come out of a sleep lasting nearly 100 million years. This black hole is located at the center of a giant galaxy that’s sending out intense radio waves. New research shows that this black hole once released massive jets of plasma stretching hundreds of thousands of light-years into space. It had been quiet for a long time but is now active again. These jets are interacting with hot gas in fascinating and complex ways.
“It’s like watching a cosmic volcano erupt after a long calm,” said Shobha Kumari, an astronomer from Midnapore City College in India. She elaborated that this black hole’s activity can create structures nearly a million light-years across.
Interestingly, only about 10% to 20% of supermassive black holes produce jets that emit radio waves. In these cases, a spinning disk of dust and plasma rotates around the black hole, feeding it material. As matter is drawn in, it creates a tangled magnetic field, which can launch some material away in giant jets. When the disk changes, these jets can turn on and off.
In a study published in the Monthly Notices of the Royal Astronomical Society, researchers used the Low-Frequency Array, a network of radio telescopes based mainly in the Netherlands, to find over 20 galaxy clusters that contain irregularly shaped radio galaxies. One focus was on a galaxy named J1007+3540, which has an unusual structure.
This galaxy holds expansive, diffuse plasma lobes that hint at jet activity going back around 240 million years. However, the study found that inside these lobes are smaller, brighter plasma jets that are about 140 million years old. This suggests that the active galactic nucleus (AGN)—where the black hole sits—has turned back on after a long period of dormancy.
“This layering of young jets within older lobes shows that the AGN experiences periods of activity and rest over cosmic timescales,” Kumari noted.
The space around J1007+3540 is filled with superheated gas, referred to as the intracluster medium. This hot gas interacts with the radio jets, altering their shape as they extend from the AGN. One of the lobes has been pushed sideways by the gas, while the other lobe shows a long, kinked tail, indicating a different interaction.
“J1007+3540 is a remarkable example of how jets interact with their surrounding environment,” commented Surajit Pal, a physicist at the Manipal Centre for Natural Sciences in India.
Studying J1007+3540 can help scientists understand how often AGNs activate and how older jets behave as they engage with their environments. Future observations will aim for higher resolution mapping of how these jets move through the intracluster medium.
This research highlights a fascinating aspect of astrophysics, illustrating how even cosmic giants have cycles of activity and rest.
