The highest energy afterglow of a Gamma-Ray Burst detected in space

The emission from the most notable Gamma-Ray Burst (GRB) explosion so far traced was found to be complex and did not follow the evolution expected in standard afterglow models.

Context

The emission from the most notable Gamma-Ray Burst (GRB) explosion so far traced was found to be complex and did not follow the evolution expected in standard afterglow models.

• The study was conducted at Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital, an autonomous institute of the Department of Science & Technology.

About the key findings of the afterglow

• The GRB with ultra-high energy photons called GRB 190114C was detected for the first time in January 2019.
  • The GRB lasted for a brief period, followed by an initial bright flash in high energies known as the ‘prompt emission’.
  • A less luminous but long-lasting counterpart known as the ‘afterglow’ was detected after the prompt emission.
  • GRB 190114C afterglow is observed as one of the brightest known afterglows.
  • The optical observations of the afterglow from GRB 190114C were carried out with the Growth India Telescope (GIT), Himalayan Chandra Telescope (HCT) (both located in Hanle, Leh, India), and Devasthal Fast Optical Telescope (DFOT, located in Devasthal, Nainital, India) as well as with upgraded Giant Meter wave Radio Telescope (u-GMRT, located in Khodad, Pune, India).
• Significance of the Study: The detection of high energy photons (TeV Photons) from the GRB provides new insights and important clues to unraveling the underlying physical processes at work which result in such explosions.
  • Detailed modeling of the afterglow indicates that the parameters describing the fraction of energy in electron population and magnetic field are evolving with time and not constant as generally seen in GRBs.
  • The evolution of these parameters may play a role in producing the bright TeV emission.