Nearby Black Hole Turns 20-Fold Radio-Brighter, Mimicking Early-Universe Growth

Q: What triggered this black hole's eight-year feeding frenzy, and why hasn't it stopped?

Astronomers do not yet know the precise trigger. The leading explanation is that the black hole entered a sudden phase of much heavier accretion, pulling in a large new supply of gas and dust at the galaxy’s center and launching a powerful relativistic jet. That jet is what produced the roughly 20-fold jump in radio brightness seen eight years ago. What makes the event remarkable is that it has not faded. In most known radio outbursts from active galaxies, the flare lasts days, weeks, or at most much shorter periods than this before dimming. Here, the radio emission has stayed strong for more than eight years, suggesting the black hole is still being fed or that the jet remains continuously energized. Researchers have not pinned down why that fueling has persisted. The broader physics offers several possibilities: a long-lived inflow of matter, sustained jet activity, or internal jet processes such as shocks or magnetic reconnection that keep accelerating particles and maintaining the radio glow. But the study does not identify a confirmed cause, and there is no evidence yet that the outburst has shut off. That uncertainty is exactly why the object is so important. It appears to be the first clear example of a new class of rapidly changing radio galaxy, giving astronomers a rare nearby laboratory for studying how black holes may have grown so quickly in the early universe.

3 articles · Updated · Space.com · Jul 10

A supermassive black hole 1.8 billion light-years away has entered a long-lasting radio-bright state after its host galaxy’s radio emission jumped 20-fold about eight years ago and has not dimmed since.
Researchers link the surge in SDSS J110546.07+145202.4 to a higher inflow of matter onto the black hole, which likely ignited near-light-speed plasma jets that boosted radio output.
The signal reached roughly 10 quadrillion times the sun’s radio brightness, and scientists say such sustained radio activity from a rapidly growing, relatively lightweight black hole had not been seen before.
Because that feeding pattern resembles the voracious growth of black holes in the early universe, the object could serve as a nearby proxy for studying how the first giant black holes evolved.
Future facilities including the SKA are expected to search for similar radio transients, potentially helping fill gaps in astronomers’ picture of early galaxy and black hole formation.

Sources

Space.com17h ago

Supermassive Black Hole in SDSS J110546.07+145202.4 Becomes 20-Fold Radio-Bright, Mimicking Early Universe

MSN17h ago

A ravenous black hole in our backyard could be our window into the ancient universe

Yahoo! Voices17h ago

A ravenous black hole in our backyard could be our window into the ancient universe

What triggered this black hole's eight-year feeding frenzy, and why hasn't it stopped?

How does this 'time machine' galaxy reveal the growth secrets of the universe's first cosmic titans?

Eight Years of Extreme Radio Brightening in SDSS J110546.07+145202.4: A Unique Local Window into Early Universe Black Hole Evolution

Overview

Since around 2018, the galaxy SDSS J110546.07+145202.4 has shown an unprecedented and long-lasting increase in radio brightness from its central supermassive black hole. This rare event stands out in astrophysics because of its intensity and duration. To understand this phenomenon, astronomers used advanced instruments like the Effelsberg 100-meter radio telescope, CSIRO's Australia Telescope Compact Array, and space-based satellites. These combined observations confirmed the unique nature of the radio emission. Importantly, the galaxy is so far from Earth that this dramatic activity poses no risk to our planet.

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