Scientists Find When Supermassive Black Holes Launch Powerful Jets After Destroying Stars
Space Science: Astronomers have uncovered a key pattern that may explain when supermassive black holes release powerful jets after tearing apart nearby stars.
A new study published in Nature Astronomy examined 20 tidal disruption events, in which stars were ripped apart by the enormous gravitational forces of supermassive black holes. Researchers used radio observations to follow the material expelled from these extreme events.
Two Distinct Jet-Launching Phases
The research indicates that supermassive black holes can produce powerful jets during two different stages of their feeding process.
The first stage occurs when a black hole is consuming material at a very high rate. A second phase can appear hundreds to thousands of days after the star is disrupted, when the feeding rate has fallen to roughly 2% of its maximum level.
These jets can propel material far into surrounding space and may influence the environments of entire galaxies.
Studying Stars Destroyed by Black Holes
When a star passes sufficiently close to a supermassive black hole, the black hole’s tidal forces can pull the star apart. This phenomenon is known as a tidal disruption event.
Only part of the disrupted stellar material is ultimately swallowed. The remaining material can form an accretion flow around the black hole, while some of it may eventually be expelled through powerful outflows and jets.
Radio Telescopes Reveal the Hidden Process
Radio observations were particularly important because they allow astronomers to track jets and outflows as they move away from the black hole.
By comparing the timing of these radio signals with the original stellar-disruption events, researchers were able to identify a recurring relationship between the black hole’s feeding rate and jet production.
Similar Behaviour Across Different Black Hole Sizes
One of the most interesting findings is that the apparent transition occurs at a similar stage of the feeding cycle seen previously in much smaller stellar-mass black holes.
This suggests that some of the physical processes controlling jet formation may operate in a similar way despite the enormous difference in the masses of the black holes involved.
Better Timing Could Improve Future Observations
The discovery could help astronomers predict when a black hole is most likely to produce a detectable jet following a stellar disruption.
More accurate predictions would allow observatories to schedule follow-up observations during periods when powerful radio emissions are most likely to appear.
Researchers can then investigate not only when jets begin, but also how their strength changes and how their properties relate to the characteristics of the black hole.
A New Window Into Extreme Cosmic Physics
The findings provide a clearer picture of what happens after a supermassive black hole destroys a star. They also strengthen the possibility that jet production follows identifiable physical conditions rather than occurring at completely unpredictable times.
Further observations of tidal disruption events will be needed to determine how universal this behaviour is and how the jets influence their surrounding galaxies.
