Delayed radio outbursts after stellar consumption
An international team has identified the cause of the powerful radio emissions that appear years after some black holes swallow stars. The emissions are now linked to a chemical process occurring in the vicinity of the event horizon.
How the late "burps" arise
By analysing observations from multiple radio observatories, scientists found that the influx of stellar material enriches the surrounding plasma with ionised gases. Over time these gases generate an unstable magnetic configuration that eventually collapses, producing a sudden radio burst.
Predicting bursts through spectral fingerprints
The researchers detected distinct spectral lines that become visible shortly after the star‑eating event. These chemical markers allow astronomers to forecast the later radio outburst well in advance.
Implications for astrophysics
The new framework provides a valuable tool for modelling the life cycles of active galactic nuclei and quantifying the feedback between black holes and their host galaxies.