Star Flash calls previous models into question

It was August 29, 2019 when HESS telescopes in Namibia recorded a gamma-ray burst in the constellation Eridanus. By astronomical standards, the eruption with catalog number GRB 190829A was very close despite the unimaginable distance of a billion light-years.

An unusually ‘close’ outbreak

Gamma ray bursts are usually very far away. We are sitting in the front row, said Olaf Reimer of the Institute for Astrophysics and Particles at the University of Innsbruck, where he leads the HESS working group, at GRB 190829A. As soon as the constellation Eridanus became visible in the night sky, the HESS-Cherenkov telescopes in Namibia focused on this outburst and were able to observe it for several days.

The aurora showed amazing properties

The afterglow of the eruption was particularly surprising to researchers. They discovered a clear similarity in the range of X-rays and gamma rays. However, well-established theories assume that the two emission components are generated by separate mechanisms.

The gamma ray spectrum also lies on the extrapolation line of the X-ray spectrum. “This is a strong indication that the gamma rays are generated by the same X-ray mechanism,” explained Anita Reimer of the HESS working group.

Better tools and strategies

Now more monitoring of gamma-ray bursts is needed. With improved instruments, such as the Cherenkov Telescope Array (CTA) currently under construction, and sophisticated observational strategies, the rate of GRB discoveries will increase and with it the ability to better understand this cosmic explosion, believes Professor Olaf Reimer, who coordinated Austrian participation in the preparation and construction of the new High Gamma Ray Observatory. CTA Energy.