Dormant Supermassive Black Hole Reactivates After 100 Million Years: Galaxy J1007+3540

Cosmic Volcano: The Awakening of an Episodic Black Hole

Astronomers led by Shobha Kumari of Midnapore City College, India, have observed a supermassive black hole at the center of galaxy J1007+3540 roaring back to life after nearly 100 million years of dormancy. This rare event, described as a "cosmic volcano," provides unprecedented insights into the life cycles of galaxies.

Active Galactic Nuclei (AGN) and Jet Formation

While supermassive black holes exist at the center of most galaxies, including our Milky Way, only a small fraction are in an active state. This reactivation occurred as the black hole began consuming nearby gas and dust, forming an Active Galactic Nucleus (AGN).

• The Outburst: The black hole ejected powerful, high-energy jets of magnetized plasma that emit radio waves.

• Discovery Tools: The breakthrough was made using India's upgraded Giant Metrewave Radio Telescope (uGMRT) and the Low Frequency Array (LOFAR) in the Netherlands.

• Episodic Activity: Radio images revealed nested layers—bright inner jets sitting inside older, dimmer debris—confirming that the black hole switches on and off over cosmic timescales.

Significance for Astronomy

The intense pressure from the surrounding hot galaxy cluster has bent and distorted these new jets, allowing scientists to map the environment of distant clusters. This discovery proves that galaxies are reshaped by repeated eruptions rather than single events.

For TNPSC and Science aspirants, this event highlights India’s leading role in radio astronomy and the critical role of AGNs in star formation and galactic evolution.