Gamma-ray bursts (GRBs) have puzzled scientists’ work for decades, but that’s about to change.
These incredibly energetic phenomena are capable of driving out matter at speeds close to the speed of light. But, unfortunately, they’re also short-lived and power bright. Luckily, we can detect them via satellites orbiting the Earth.
Thanks to a recent finding, scientists are finally solving a long-standing theoretical prediction that could support future scientific work.
Here is what you need to know.
Decoding Gamma-ray Bursts
An international team of scientists succeeded in measuring the magnetic field in a far-off Gamma-Ray Burst. The new work finally confirms that the magnetic field in the GRBs ends scattered after the ejected material crashes into, and blows, the surrounding environment.
“We measured a special property of the light – polarisation – to directly probe the physical properties of the magnetic field powering the explosion; [it] solves a long-standing puzzle of these extreme cosmic blasts,” explains Prof Carole Mundell, head of Astrophysics at Bath and gamma-ray expert.
Study insights: how they really did it?
As per scientists’ findings, the quest implies capturing the light early, right after a blast. Then, decoding the physics of the burst.
The prediction states that any primordial magnetic fields will be killed in the end due to the expanding shock front clashes with the enclosing stellar debris.
Such a model foretells light with some elevated levels of polarisation right after the blast, when the large-scale initial field is still sound and pushing the flow.
Furthermore, that light should be primarily unpolarised as the field is jumbled in the impact.
The team led by Mundell was the first to find extremely polarised light just after a few minutes after the blast. They confirmed the appearance of primordial fields with large-scale structure.
Finally, the team was also able to prove the following:
- the burst was triggered (most likely) by the crash of ordered magnetic fields in the first moments of a black hole’s formation;
- the magnetic field length scales were way smaller than previously believed;
- the light originated in the forward shock.
The team still needs to figure more things out, so expect new data soon!