FOCUS ON GAMMA-RAY BURSTS MIGHT BE MUCH RARER THAN WE THOUGHT.

Simulations of black hole birth are unlocking the secrets of these bright-light phenomena

- Tereza Pultarova

The first-ever 3D simulation of the formation of a black hole jet reveals why mysterious gamma-ray bursts appear to blink and suggests that these mysterious phenomena might be much rarer than astronomers suspected. Gamma-ray bursts are the brightest and most powerful flashes of light known to exist in the universe. First detected in 1967, these blinding light explosions are generated when massive stars collapse into black holes, launching jets of material that squirt into space at nearly the speed of light.

Currently, satellites spot about one gamma-ray burst somewhere in the universe every day. But astronomers think that up to 500 may flash through the universe without us knowing every day. However, a new study suggests the actual number might be ten times lower. The study, by a team of astronomers from Northwestern University, simulated for the first time in detailed 3D the birth of black hole jets powered by collapsing stars. The simulation showed that as a massive star collapses, a black hole starts to form at its heart, surrounded by a disc of infalling material. In some cases, the material in the black hole’s vicinity can be accelerated into a jet that escapes the black hole’s gravitational pull. All this is happening while the nascent black hole is still surrounded by the envelope of the dying star.