Telescopes document extreme explosion

21 November 2019

Astronomers at Oxford University’s Physics Department have been involved in the first-ever detection of a gamma-ray burst (GRB) by a ground-based high-energy telescope. The GRB, likely associated with the catastrophic explosion of a massive star, was first detected on January 14, 2019, by the orbiting Swift and Fermi satellites.

A major breakthrough

The ground-based high-energy telescope, MAGIC, responded automatically to the event and started taking data within 50 seconds of the burst; for the first time from such an event, it detected photons of Tera-electronvolt energise – a trillion times more energetic than visible light. This is the first time a GRB has been detected at such high energies from the ground, and marks a major breakthrough in tests of the underlying astrophysics.

Following the explosion, shock waves propagate outwards at close to the speed of light, producing emission detectable at radio wavelengths. Astrophysicists Ian Heywood and Rob Fender were involved in radio observations with the MeerKAT radio telescope which detected this radio afterglow.

Ian commented: ‘Radio observations are a vital way to study the evolving aftermath of these extremely energetic events. Although MeerKAT is one of the newest radio telescopes in the world, it has rapidly proven to be the most powerful one in its class, with increasing involvement in truly global observational campaigns such as this one. We are very excited about Oxford’s close involvement with this telescope, and the discoveries that will be made with it in the coming months and years.’

Observation of inverse Compton emission from a long gamma-ray burst by MAGIC Collaboration et al is published in Nature.

MeerKAT image © SKA South Africa