Black Hole Jets May Ignite at the Same Feeding Threshold Across Mass Scales
Astronomers compared stellar-mass black holes with supermassive ones and found both can launch jets when their accretion rate drops to roughly 2% of the Eddington limit. The study used tidal disruption events, where a star is torn apart, to observe supermassive black holes during rapid changes in feeding. The result suggests jet production may follow similar physics regardless of black hole size.
The study, published in Nature Astronomy, was led by Adelle Goodwin at Curtin University’s ICRAR and the Forrest Research Foundation, with Andrew Mummery at Princeton’s Institute for Advanced Study. It contrasts black holes around ten solar masses with supermassive ones millions of times heavier, yet finds both may begin launching jets near the same accretion level.
To observe this, researchers used tidal disruption events, where a star is pulled apart. They examined 20 such events with optical, ultraviolet, X-ray, and radio data from observatories in Australia, the United States, India, South Africa, and space, then modeled 10 closely enough to compare feeding rates with radio outflow timing.
This finding may shape how astronomers interpret black hole activity and design future observations, potentially improving models of jet feedback in galaxies. For the public, clearer connections between small and giant black holes could enrich science education and media coverage. Space agencies and observatories might benefit from prioritizing coordinated radio and multiwavelength monitoring of tidal disruption events, though practical applications remain distant and speculative.