Astronomers using the X-SHOOTER instrument at ESO’s Very Large Telescope (VLT) have detected light from a gamma-ray burst at a redshift of 6.3, meaning the light departed more than 12.8 billion years ago. This discovery is a rare occurrence that, thanks to the extreme luminosity of such sources, offers a window into the infant Universe, which is otherwise difficult to observe.
This image, taken by the X-SHOOTER instrument at ESO’s Very Large Telescope (VLT), shows light from GRB 210905A (center). Image credit: ESO / Rossi et al.
Gamma-ray bursts (GRBs) are the intrinsically brightest explosions known in the Universe.
These events last from seconds to minutes, and originate during the formation of a black hole accompanying a beamed supernova or colliding neutron stars.
The narrow beam of intense GRB radiation can only be seen when the jet points toward Earth, but such an event can be seen across the breadth of the Universe.
In September 2021, NASA’s Neil Gehrels Swift Observatory detected a very energetic GRB event dubbed GRB 210905A.
INAF astronomer Andrea Rossi and colleagues then observed its aftermath with a number of telescopes around the world, including several ESO instruments on the VLT and the robotic telescopes REM and GROND hosted at ESO’s La Silla Observatory.
Besides taking images with X-SHOOTER, they also used this instrument to obtain spectra.
This was key to discover that the burst originates from an extremely distant galaxy, when the Universe was only 6% of its current age, making this one of the most distant GBRs ever found.
“The origins of gamma-ray bursts, however, remain a bit of a mystery,” the astronomers said.
“This particular GRB put out so much energy that it was probably powered by material falling onto a black hole or (less likely) a magnetar — a neutron star with a very strong magnetic field.”
“With ESO’s upcoming Extremely Large Telescope, properties of bursts like this and their progenitors can be studied in greater detail, and their elusive origin can be uncovered.”
The team’s results were published in the journal Astronomy & Astrophysics.
_____
A. Rossi et al. 2022. A blast from the infant Universe: The very high-z GRB 210905A. A&A 665, A125; doi: 10.1051/0004-6361/202243225
Source link: https://www.sci.news/astronomy/gamma-ray-burst-early-universe-11251.html
