New Model Sheds Light on the Universe's Most Powerful Explosions

Astronomers have taken a closer look at one of the most powerful explosions in the universe: gamma-ray bursts.

These rare explosions occur when extremely massive stars go supernova. The stars' strong magnetic fields channel most of the explosion's energy into two powerful plasma jets, one at each magnetic pole. The jets spray energetic particles for light-years in both directions, at close to light speed.

Scientists have long suspected that GRBs are the source of at least some of the cosmic rays detected on Earth. Now, researchers have begun to study whether or not this is the case by building some of the most detailed computer simulations ever made of a GRB jet's internal structure.

"Previously, the details of the non-uniformity of the GRB jets were not too important in our models, and that was a totally valid assumption-up until IceCube saw the first cosmic neutrinos a couple of years ago," said Mauricio Bustamante, one of the researchers, in a news release. "Now that we have seen them, we can start excluding some of our initial predictions, and we decided to go one step further and do this more complex analysis."

One implication of the model is that the rate of neutrino production in GRBs might be lower than previously thought, so only about 10 percent of neutrinos detected on Earth are likely to come from GRBs. The density of neutrinos that reach Earth is called the neutrino flux, and the model predicts that the likely neutrino flux from GRBs is below the threshold of detection for today's neutrino telescopes.

The findings are published in the journal Nature Communications.

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