Dormant Supermassive Black Hole Awakens After 100 Million Years of Silence

A supermassive black hole at the centre of galaxy J1007+3540 has roared back to life after nearly 100 million years of dormancy. New radio images reveal its freshly reignited jets battling against the dense surroundings of a massive galaxy cluster. The discovery offers a rare glimpse into how such cosmic giants evolve over time.

The black hole's awakening was captured using data from the Low Frequency Array (LOFAR) and India's upgraded Giant Metrewave Radio Telescope (uGMRT). Radio images show a bright, compact inner jet—proof of the recent eruption—nestled within older, faded plasma left by past outbursts. This layering of young and ancient emissions highlights the black hole's turbulent history of switching on, shutting down, and restarting over vast timescales.

The surrounding galaxy cluster is violently shaping the jets. The northern lobe appears compressed and twisted, with plasma forced sideways by the dense gas. Meanwhile, a faint, wispy tail stretches millions of light-years to the southwest, marking the path of magnetised plasma dragged through the cluster. These features suggest the jets are being bent, squeezed, and torn apart by their environment.

Researchers published their findings in Monthly Notices of the Royal Astronomical Society, noting that J1007+3540's combination of restarted activity, enormous scale, and intense external pressure makes it a key case study. The team now plans further high-resolution observations to examine the black hole's core and track how the new jets push through the chaotic cluster.

The study confirms that J1007+3540 has undergone multiple eruptions, with its central engine flickering on and off over cosmic time. Future observations will help astronomers understand how such restarted jets interact with their surroundings. The findings also underscore the role of galaxy clusters in shaping the behaviour of supermassive black holes.