On 5 September 2021 astronomers discovered light from the high-energy gamma flash GRB 210905A with a red shift of more than 6. This could be one of the most energetic and distant GRB ever discovered: the event that produced this gamma flash probably occurred when the universe was only 880 million years old.
Gamma flashes or a merger of two neutron stars; most GRB sources are at a distance of billions of light years from the Earth, in distant galaxies.
The light from this gamma flash flew more than 12.8 billion years before reaching Earth. An international group of researchers led by Dr. Andrea Rossi, a scientist at the Italian National Institute of Astrophysics, studied after-lighting for several months to better understand the star event that caused it. GRB was not only one of the most distant and energetic ever discovered but also one of the brightest things ever recorded.
Careful tracking at all wave lengths
GRB, which is referred to here, GRB 210905A, is a "long" type, which corresponds to a gamma-radiation of more than two seconds, usually from the explosions of very massive stars. The so-called "short" GRB, which lasts less than two seconds, is usually associated with the collision of compact objects such as neutron stars.
This bright burst was first detected by instruments on board the Swift Observatory, intended for observation by GRB, and by KONUS, a "hunter" for GRB on NASA WIND. After the discovery of the first flash, astronomers continued to observe for another eight months using a combination of ground and space telescopes, including the Hubble, Swift and Chandra telescopes.
"," says Dr. Rossi. These subsequent observations, carried out in X-rays, visible and near infrared bands, allowed the team to determine the red offset of the radiation source: it is estimated at 6.3.
GRB 210905A
Features similar to those of later GRB
Burst Alert Telescope data are too large for a standard magnet, suggesting that a recent black hole was likely the driving force of the surge.
Scientists were surprised to find that despite the long-standing nature of the event that had given rise to GRB, the phenomenon showed properties that were surprisingly similar to those seen in GRB due to explosions that occurred much later and much closer to Earth.
In other words, the mechanism responsible for GRB does not evolve with the universe.
This discovery allows for a better understanding of how massive stars form and evolve in the early stages of the universe. Now researchers hope to deepen their understanding of the original explosion using the James Webb telescope, which can reveal new features of the massive star that caused GRB. ", notes the team, referring in particular to the European Space Agency THESEUS and NASA Gamow Explorer project.
It should be noted that most of the astronomers studying GRB are members of the STARGATE, which is dedicated to the atmosphere of the exoplanet using space telescopes. Professor Carol Mandela, an astronomer from the University of Bata and co-author of GRB study 210905A, said: "".