Latest In

News

A Bizarre Gamma Ray Burst Deviates From The Rule

A luminous gamma ray burst (GRB)has been seen, which challenges astronomers' understanding of these explosive cosmic eruptions. For a long time, astronomers believed that GRBs came in two varieties: long (lasting more than two seconds) and short (fading out immediately).

Author:Hajra Shannon
Reviewer:Paula M. Graham
Dec 09, 20221.1K Shares78.6K Views
A luminous gamma ray burst(GRB)has been seen, which challenges astronomers' understanding of these explosive cosmic eruptions.
For a long time, astronomers believed that GRBs came in two varieties: long (lasting more than two seconds) and short (fading out immediately). Various astronomical occurrences have been associated with each kind. Last year, however, two NASA space telescopes detected a short GRB masquerading as a long GRB; this event lasted for a long period yet had its genesis in a short GRB.
We had this black-and-white vision of the universe. This is the red flag that tells us, nope, it’s not. Surprise!- Eleonora Troja, Tor Vergata University
On December 7, Troja and colleagues reported in five separate studies published in Natureand Nature Astronomythat GRB 211211A is the first burst that conclusively fractures the pair.

NASA’s Fermi, Swift Capture Revolutionary Gamma-Ray Burst

What Are Gamma Ray Bursts?

The uncommon cosmic explosion that produced a richness of heavy metals like gold and platinum in December 2021 was discovered by numerous telescopes as an unusually intense flash of light. Among the most powerful and brightest explosions in the cosmos are gamma-ray bursts, which may last anywhere from minutes to hours.
Due to the length of the burst, it is likely that it was triggered by the explosion of a huge star during its death in a supernova. Astronomers examining the event also saw an abundance of infrared light, but the gamma-ray burst's afterglow was weak and vanished more swiftly than those produced by supernovae.
Rare but huge kilonovas are the result of catastrophic collisions between neutron stars, the extraordinarily dense leftovers of exploding stars, or between neutron stars and black holes.
Using data from the X-shooter instrument on ESO's Very Large Telescope, a European research team identified traces of strontium generated in a neutron-star merger. This depiction of a kilonova explosion is an artist's conception of the moment when two very compact neutron stars collide and explode. Newly synthesized strontium is shown front and center.
Space fireworks were generated when two neutron stars collided. Astronomers were already perplexed by the length of the gamma-ray burst before they learned that a kilonova was responsible for the infrared radiation. These uncommon explosions typically produce gamma-ray bursts that last less than two seconds, but this signal persisted for as least a minute.

How Gamma Ray Bursts Produced

On December 11, 2021, NASA's Swift and Fermi space telescopes spotted the explosion in a 1.1 billion-light-year galaxy. According to Northwestern University astronomer Wen-fai Fong, it was a typical extended gamma-ray burst.
GRBs are near. According to Nature, Fong's and Troja's teams were able to independently see the explosion using ground-based telescopes. No supernova emerged for weeks, confusing researchers. The source of the GRB released substantially more optical and infrared radiation than usual for a lengthy GRB.
After ruling out alternative theories, Troja and colleagues compared the burst's aftereffects to the first kilonova seen with gravitational waves. Near-perfect match.
That’s when many people got convinced we were talking about a kilonova.- Eleonora Troja, Tor Vergata University
Troja claims it was a kilonova in hindsight. It seemed unbelievable, like spotting a lion in the Arctic.
It looks like a lion, it roars like a lion, but it shouldn’t be here, so it cannot be. That’s exactly what we felt.- Eleonora Troja, Tor Vergata University
What happened? Merging neutron stars quickly become black holes. The black hole swallows superheated material that emits gamma rays in two seconds. How did GRB 211211A shine for over a minute?
The neutron stars may have combined into a bigger neutron star that momentarily withstood the pressure to collapse into a black hole. Gompertz argues that affects basic physics that specifies how hard it is to smash neutrons into black holes.
A neutron star may have collided with a tiny black hole roughly five times the mass of the sun instead of another neutron star. The black hole ate the neutron star longer.
In Nature, astronomer Bing Zhang of the University of Nevada, Las Vegas and colleagues propose a neutron star-white dwarf merger. He proposes a third progenitor that is distinct from the first two. White dwarfs, leftovers of smaller stars like the sun, are less dense than neutron stars. If a massive white dwarf collides with a neutron star, a kilonova may result.
A magnetar may be the consequence. Zhang thinks the magnetar might have kept pushing energy into gamma rays and other wavelengths, prolonging the burst. GRB 211211A is a major physics event.
Figuring out what caused it might clarify how heavy atoms in the cosmos develop. Some protracted GRBs that scientists assumed were supernovas may be mergers. To understand more, scientists need to locate more of these binary-busting GRBs, plus measurements of gravitational waves at the same moment. When LIGO returns in 2023, Trejo believes they'll receive that.
I hope that LIGO will produce some evidence,” Kouveliotou says. “Nature might be graceful and give us a couple of these events with gravitational wave counterparts, and maybe [help us] understand what’s going on.- Chryssa Kouveliotou, George Washington University

Final Words

The precise process that resulted in the gamma ray burst's development has remained a mystery. One of the recent investigations, however, uncovered numerous additional "oddball" gamma ray burst possibilities with extended durations and likely kilonova origins by searching a database of previous gamma-ray observations, indicating this unexplained light in the sky was no flash in the pan.
These results challenge the status quo of the last two decades of research into the causes of gamma ray bursts, but they also point the way toward uncovering its mysteries.
Jump to
Hajra Shannon

Hajra Shannon

Author
Paula M. Graham

Paula M. Graham

Reviewer
Latest Articles
Popular Articles