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Detection of the highest-energy photons from a gamma-ray burst reported in Nature

Gamma-ray bursts (GRBs) are the most violent explosions in the Universe suddenly appearing in the sky, about once per day. They are thought to result from the collapse of massive stars or the merging of neutron stars in distant galaxies. They commence with an initial, very bright flash, called the prompt emission, with a duration ranging from a fraction of a second to hundreds of seconds. The prompt emission is accompanied by the so-called afterglow, a weaker but longer-lasting emission over a broad range of wavelengths that fades with time. 

The two papers published in Nature on 2019 November 21 report the first ever detection of very-high-energy photons from a GRB in the range of 0.2–1 teraelectronvolts from around one minute after the burst. The GRB detected by the MAGIC telescopes reveals the highest energy photons measured from these objects. 

This ground-breaking achievement by MAGIC provides critical new insight for understanding the physical processes at work in GRBs, which are still mysterious. The photons detected by MAGIC must originate from a process hitherto unseen in the afterglows of GRBs, clearly distinct from the physical process that is known to be responsible for their emission at lower energies.

MAGIC (Major Atmospheric Gamma Imaging Cherenkov) is a system of two 17 meter diameter telescopes located at the Canary island of La Palma, Spain, and designed to perform gamma-ray astronomy in the energy range from 30 GeV to more than 50 TeV.

The MAGIC telescopes are run by an international collaboration of scientists, engineers and technicians from 12 countries. University of Oulu is represented in the MAGIC collaboration by Dr. Vitaly Neustroev from Astronomy Research Unit. He is one of the co-authors of the Nature articles.

MAGIC telescope on the Canary island La Palma, Spain.

More information:

MAGIC press release

Nature articles:
Teraelectronvolt emission from the γ-ray burst GRB 190114C
Observation of inverse Compton emission from a long γ-ray burst

Photo: NASA/Swift/Aurore Simonnet


Last updated: 21.11.2019