Space scientists solve a decades-long gamma-ray burst puzzle - Space Bollyinside - BollyInside

The magnetic fields can’t be seen directly, but their signature is encoded in the light produced by charged particles (electrons) that whiz around the magnetic field lines.

The challenge is to capture the light as soon as possible after a burst and decode the physics of the blast, the prediction being that any primordial magnetics fields will ultimately be destroyed as the expanding shock front collides with the surrounding stellar debris.

Mundell’s team was first to discover highly polarised light minutes after the burst that confirmed the presence of primordial fields with large-scale structure.

In contrast, a team of Japanese astronomers announced an intriguing detection of 10% polarised light in a GRB, which they interpreted as a polarised forward shock with long-lasting ordered magnetic fields.

The light originated in the forward shock.The magnetic field length scales were much smaller than the Japanese team inferred.The blast was likely powered by the collapse of ordered magnetic fields in the first moments of the formation of a new black hole.The mysterious detection of polarisation by the Japanese team could be explained by a contribution of polarised light from the primordial magnetic field before it was destroyed in the shock.