Black Hole Activity in Ancient Galaxy Discovered

Dormant Black Hole in J1007+3540 Galaxy Reawakens After 100 Million Years

after a century of quiet, a supermassive black hole at the center of the J1007+3540 galaxy has sprung back to life, exhibiting a dramatic outburst of energy reminiscent of a “cosmic volcano.” This rare event, observed through radio data, offers new insights into the cyclical nature of active galactic cores adn their influence on galaxy evolution.

Did you know? – Supermassive black holes reside at the center of most galaxies, including our Milky Way. However, not all are actively feeding and emitting energy.

Astronomers detected a shining, fresh internal jet extending almost 1.5 million light-years, erupting through remnants of older plasma. “It’s like watching another cosmic volcano erupt after centuries of calm,” explained Shobha Kumari, led researcher at Midnapore City College in India. This arrangement is considered a rare example of an episodic giant galaxy radio source.

Most galaxies, including our own Milky Way, host a supermassive black hole. However, J1007+3540 stands out due to its powerful and recurring activity.the galaxy emits jets of magnetized plasma that extend far beyond its visible stars, dwarfing even entire galaxy clusters. Evidence suggests the black hole has repeatedly switched on and off over vast stretches of time.

Radio images reveal a compact, bright jet-an unmistakable sign of the recent black hole awakening. Surrounding this new activity are the distorted remains of previous eruptions, estimated to be 240 million and 140 million years old, respectively. The black hole itself had been dormant for approximately 100 million years before this latest outburst.

An image from LOFAR DR2, overlaid on optical data from Pan-STARRS, clearly showcases the compact, bright internal jet, confirming the reawakening of the dormant supermassive black hole. (LOFAR/Pan-STARRS/S. Kumari i in.(CC BY 4.0))

Further analysis of the LOFAR image reveals a compressed and distorted north lobe, indicating a retreating plasma flow being pushed aside by surrounding gas. In the southwest, a magnetized plasma trail stretches across a large area, shaped by the galaxy’s environment, suggesting the galaxy is not only emitting jets but also being sculpted by external forces.

This revelation is significant because the build-up of young jets within older lobes signifies an episodic active galactic core-a galaxy whose central engine cycles on and off over cosmic timescales. Previously, galaxies were frequently enough viewed as evolving in isolation, but this finding suggests the black hole’s activity directly regulates the growth of the galaxy itself. This process isn’t always smooth and continuous; it can be cyclical and violent, punctuated by periods of intense black hole activity.

Pro tip – Radio telescopes are crucial for observing these events because they detect the emissions from the magnetized plasma jets, which are invisible to optical telescopes.

The host galaxy, J1007+3540, is a massive elliptical galaxy where stars formed 12 billion years ago and continue to form new ones. The scale of the jets emitted by its central black hole is immense, exceeding the size of the Milky Way.

Scientists plan to utilize advanced X-ray telescopes, such as the Chandra Space Telescope, to map the hot gas surrounding this system, providing a more comprehensive understanding of the black hole’s influence.

Reader question – How do black holes “turn on” and “off,” and what triggers these cycles of activity? What are your thoughts?

why did this happen? The supermassive black hole in J1007+354