The Black Holes That Burp Years After They Eat
Astronomers found that some supermassive black holes emit bright radio flares years after consuming a star, a delayed effect likened to "burping." Using the Very Large Array, they observed that these flares happen when the black hole's jets later interact with surrounding gas, changing our understanding of tidal disruption events.
Background
- Supermassive black holes at the center of galaxies sometimes "burp" (erupt with jets or radiation) years or even decades after consuming a star or gas cloud — a phenomenon known as "delayed tidal disruption."
- Astronomers used to assume black holes swallowed things immediately; this discovery shows the process can pause, with material lingering in an accretion disk before being ejected.
- The finding comes from repeated observations of the same galaxies over many years, enabled by surveys like ZTF (Zwicky Transient Facility) and follow-ups with X-ray and radio telescopes.
- This matters because it challenges simple models of black hole feeding, reveals complex dynamics around black holes, and could explain some of the high-energy particles and radiation observed across the universe.
- Key players: ZTF (a ground-based sky survey in California), NASA's Swift and Chandra (X-ray observatories), and multiple university teams analyzing archival data.