Astronomers have discovered an ancient, very distant gamma-ray burst

In September 2021, NASA’s Neil Gerels Swift Observatory was peering through eons and ages when it spotted a spectacular explosion, a gamma-ray burst (GRB), that occurred in the early universe.

The object now known as GRB210905A looks like the universe was still young, as it took 12.8 billion years for its light to reach Earth. As the intense light from the gamma-ray burst quickly fades, as does its afterglow, astronomers rushed to capture what was left as an orange-red dot with several instruments at the ESO’s Very Large Telescope in Chile, including its X-Shooter spectrograph. , as well as robotic telescopes at the La Silla Observatory, also in Chile, the statement said. (will open in a new tab) from the institution.

Gamma radiation is produced by certain types of particle collisions and the nuclear decay of radioactive substances (one of the reasons nuclear waste is so infamous). Astronomers believe that flashes of these powerful electromagnetic rays flare in the darkness of space at least once a day, and gamma-ray bursts are among the brightest phenomena, but they do not linger for long.

On the subject: Astronomers just noticed the most powerful flash of light ever seen

Although gamma-ray bursts are visible, astronomers carefully measure how much light the burst emits at different wavelengths. As with all light sources in space, as the wavelengths of light stretch out in the void, the GRB signal shifts to the red end of the spectrum. The amount of signal change, called redshift, reflects how far away the source is, with very distant signals often becoming infrared light.

While the human eye can’t see infrared light, an instrument like the X-Shooter can, and that’s how the researchers figured out the object’s distance and the time it took for its light to reach Earth. Such distant objects are usually difficult to observe because they are often dim, but GRBs such as GRB210905A are extremely bright and can be detected if caught and imaged fast enough.

“Gamma Bursts [this distant] “These are rare events… but they are only a small part of the large population that future proposed missions promise to uncover,” team leader Andrea Rossi, an astronomer at INAF’s Bologna Research Center in Italy, and colleagues wrote in a study of the observations published in September 2018. of the year. 21 in the journal Astronomy and Astrophysics.

So where do these mysterious flashes of light come from? The researchers believe that the gamma-ray burst got its luminous power from material that was pulled by the black hole’s gigantic gravity. The scientists ruled out the possibility that the signal came from a magnetar — an extremely compact, dead core of a massive star with enormous magnetic energy — because GRB210905A had too much energy for a magnetar.

The more information about gamma-ray bursts is demystified, the more can be learned about what the universe was like in its youth.

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