Sunday, December 11, 2022

A Once-in-500-Year Event: The most energetic gamma-ray burst recorded so far in October 2022

Amazing stuff! What are the human health implications of such events?

The pre-print of this paper was published in early March 2022:
"In an amazing coincidence, an article predicting the maximum energy of GRBs written by researchers ... was accepted for publication in The Astrophysical Journal Letters ... Entitled “The Maximum Isotropic Equivalent Energy Of Gamma Ray Bursts,” the article predicted not only the strength of the eruption but also its other characteristics. ...
A gamma ray burst is a cosmic event during which a huge amount of gamma rays and X-rays is emitted within seconds in a single pulse or in several adjacent pulses. Some 25 years ago [researchers] published an article suggesting the possibility that gamma-ray bursts may be responsible for some of the past major extinctions of life on Earth.
Gamma bursts were first discovered in 1967, when the USA sent satellites to detect possible Soviet nuclear tests in space. Such tests were prohibited by an international agreement, but the Americans suspected that the USSR was conducting them in space on the assumption that it would be impossible to detect them from Earth due to the atmospheric absorption of x and gamma rays. Six years later, in 1973, only after it became clear that they were not caused by humans, their existence was published.
In the first two decades after the discoveries of gamma-ray bursts, most of the scientific community believed these events were taking place in the Milky Way, which is “our” galaxy. Only in 1991 did the U.S. National Aeronautics and Space Administration (NASA) obtain observational evidence that these events occur mainly in other, very-distant galaxies. ..."

"... Astronomers around the world are captivated by an unusually bright and long-lasting pulse of high-energy radiation that swept over Earth Sunday, Oct. 9 [2022]. The emission came from a gamma-ray burst (GRB)the most powerful class of explosions in the universe – that ranks among the most luminous events known.
On Sunday morning Eastern time, a wave of X-rays and gamma rays passed through the solar system, triggering detectors aboard NASA's Fermi Gamma-ray Space Telescope, Neil Gehrels Swift Observatory, and Wind spacecraft, as well as others. Telescopes around the world turned to the site to study the aftermath, and new observations continue. ..."

From the abstract:
"The canonball model, which unifies cosmic ray bursts (CRBs) and gamma ray bursts (GRBs), is used to predict the maximum isotropic equivalent gamma ray energy release in a GRB. The predicted maximum is based on the observed knee around 1 TeV in the energy spectrum of Galactic cosmic ray electrons, and on the Amati correlation in GRBs. Both were predicted by the cannonball model of CRBs and GRBs before their empirical discoveries. The predicted maximum agrees well with that concluded from up to date GRB observations."

A Once-in-500-Year Event On October 9, the most energetic gamma-ray burst (GRB) ever measured was observed. The burst, which occurred 2.4 billion light-years from Earth, was documented as GRB 221009A.



Swift’s X-Ray Telescope captured the afterglow of GRB 221009A about an hour after it was first detected. The bright rings form as a result of X-rays scattered from otherwise unobservable dust layers within our galaxy that lie in the direction of the burst.


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