Astronomers Have Found The Farthest Optical Trace Of A Gamma-Ray Burst
Astronomers have registered the farthest optical signal left after a short gamma-ray burst SGRB181123B, which went to Earth 10 billion years, according to an article accepted for publication in the Astrophysical Journal Letters and available on the site arXiv.org. The researchers' discovery confirms the hypothesis that stars formed very quickly in the early Universe, and mergers of neutron stars, which are considered the "progenitors" of fast gamma-ray bursts, occurred quite often.
Gamma-ray bursts are one of the highest-energy processes in the Universe. They can be short (up to two seconds), long, and extra-long (from 10,000 seconds). It is believed that short gamma-ray bursts occur as a result of the rapid absorption of compact objects by black holes and the merging of neutron stars. Today, thanks to gravitational wave detectors, astronomers are increasingly recording recent events, but they rarely catch signals from neutron star mergers in the early Universe (redshift z > 1).
Astronomer Kerry Paterson (Kerry Paterson) from the Harvard-Smithsonian center for astrophysics, along with colleagues, reported the discovery of a cosmic glow left after the flash when merging neutron stars. The gamma-ray burst was first recorded in August 2018 by the Gehrels Swift Observatory, after which scientists observed the event using the Gemini North telescope. For subsequent research, the astronomers used the Gemini South telescopes, the MMT, and the Keck Observatory.
Scientists were also able to find out in which galaxy the flash occurred and determine its redshift. SGRB181123B was the second-longest gamma-ray burst known today and the first among those whose afterglow was "caught" (z = 1.754). The event occurred 3.8 billion years after the Big Bang, and the brightness of the optical flash reached 25.1 magnitudes.
Since SGRB181123B occurred when the Universe was only about 30 percent of its present age, IT provides a rare opportunity to study the merging of neutron stars, which are formed in the final stages of the life of stars, at a relatively early period in cosmic history. Researchers suggest that when the gamma-ray burst occurred, space was filled with actively forming stars and galaxies, and massive binary stars, apparently, passed through all stages of evolution quite quickly.
High-energy gamma-ray bursts are often used to test the laws of physics. For example, scientists have recently obtained lower limits on the amount of energy at which the Lorentz invariance can be violated by analyzing gamma-ray burst radiation.they have also proposed a modification of the gamma-ray burst glow model, which implies that matter in a jet moves higher than the local speed of light in matter, but does not exceed the speed of light in a vacuum.