Astronomers have captured one of the clearest views yet of an active “reborn” black hole, revealing a dramatic explosion that has been compared to a “cosmic volcano” stretching almost a million light-years into space.
The discovery focuses on galaxy J1007+3540, where scientists observed the supermassive black hole at its center suddenly restart its powerful jets after being inactive for almost 100 million years.
Jet plane collides with extreme galaxy cluster environment
Radio observations show that galaxies are engaged in a fierce struggle. The newly reactivated jet from the black hole is pushed outward, but it is distorted and compressed by the intense pressure of the massive galaxy cluster that surrounds it.
The survey results are Royal Astronomical Society Monthly Notices These are based on observations from highly sensitive radio equipment. These include the Low Frequency Array (LOFAR) in the Netherlands and the Improved Giant Meter Wave Radio Telescope (uGMRT) in India.
Evidence of repeated eruptions of black holes
Most galaxies contain supermassive black holes, but only a few produce giant jets of magnetized plasma that emit radio waves. J1007+3540 stands out because it clearly shows multiple cycles of activity, indicating that its central black hole is switching on and off over long periods of time.
The images reveal a bright, compact internal jet indicating recent activity. Around it is a larger region of old, fading plasma left behind by previous eruptions. This ancient material appears to have been stretched and compressed by the harsh conditions of the surrounding cluster.
“It’s like watching a space volcano erupt again after years of calm, except this volcano is large enough to carve out a structure that stretches nearly a million light-years through space,” said lead researcher Shobha Kumari from India’s Midnapore City University.
“The dramatic layering of young jets within old, exhausted lobes is characteristic of episodic AGNs, galaxies whose central engines cycle on and off over cosmic timescales.”
Scientists identify rare episodic AGN
The study was conducted by Kumari with Dr. Sabyasachi Pal of Midnapore City University, Dr. Surajit Paul of Manipal Natural Science Center in India, and Dr. Marek Jamrozi of Jagiellonian University in Poland.
“J1007+3540 is one of the clearest and most spectacular examples of episodic AGN with jet cluster interactions, where the surrounding hot gas bends, compresses, and distorts the jet,” Dr. Pal explained.
Extreme pressure forms black hole jets
J1007+3540 is embedded within a giant cluster filled with extremely hot gas. This creates a strong external pressure, much larger than what is typically seen in most radio galaxies. As the jet expands outward, it is forced to bend and twist as it interacts with this dense environment.
Images from LOFAR show that the galaxy’s northern lobe is highly compressed and distorted. The data reveals a curved stream of plasma that appears to be pushed sideways by the surrounding gas.
Meanwhile, observations from uGMRT show that this compressed region has a very steep radio spectrum. This means that the particles there are very old and have lost much of their energy, further highlighting the effects of the cluster’s extreme conditions.
A galaxy shaped by its surroundings
Another notable feature is a long, faint luminescent tail that extends toward the southwest. This structure shows that magnetized plasma is dragged through the cluster, leaving behind a diffuse trail that lasts millions of years.
According to the researchers, this suggests that galaxies are not only producing powerful jets, but are also being reshaped by their surrounding environment.
Insights into the period of black holes and the evolution of galaxies
Systems like J1007+3540 provide valuable clues about how black holes behave over time. These help scientists understand how often black holes switch between active and quiescent states, how jets change over time, and how the surrounding environment changes the overall structure of galaxies.
The combination of new activity, massive scale, and strong environmental influences make this galaxy an important example of how galaxies evolve. Rather than growing in a smooth and stable manner, this process appears to involve a continuous tension between the explosion of a powerful black hole and the pressure of the surrounding cosmic environment.
By studying this system, astronomers have gained the following insights:
- How often does a black hole switch between active and quiet periods?
- How old radioplasmas interact with hot cluster gases
- How repeated eruptions reshape galaxies over time
what happens next
The research team plans to conduct more detailed observations using higher-resolution instruments. Their goal is to take a closer look at J1007+3540’s central region and track how the newly restarted jet moves through this complex environment.
Understanding galaxies like J1007+3540 is key to revealing how black holes affect their surroundings, and how galaxies themselves grow, go dormant, and become active again over cosmic time.
