NASA’s Fermi Gamma-ray Space Telescope has confirmed star wrecks as source of extreme cosmic particles. Here is all you need to know.
How aware are you about our galaxy? Have you heard about PeVatron? NASA has informed that a PeVatron is a scientific term, a source for some of the highest-energy particles known to whip across our galaxy. “A PeVatron isn’t a robot from a 1950s sci-fi movie: it’s a scientific term, a source for some of the highest-energy particles known to whip across our galaxy. PeVatrons are notoriously hard to pin down—but our Fermi telescope might be closing in on one,” NASA tweeted.
“Astronomers have long sought the launch sites for some of the highest-energy protons in our galaxy. Now a study using 12 years of data from NASA’s Fermi Gamma-ray Space Telescope confirms that one supernova remnant is just such a place,” NASA said in a report. Fermi has shown that the shock waves of exploded stars boost particles to speeds comparable to that of light. Called cosmic rays, these particles mostly take the form of protons, but can include atomic nuclei and electrons.
“Because they all carry an electric charge, their paths become scrambled as they whisk through our galaxy’s magnetic field. Since we can no longer tell which direction they originated from, this masks their birthplace. But when these particles collide with interstellar gas near the supernova remnant, they produce a tell-tale glow in gamma rays – the highest-energy light there is,” NASA added.
“Theorists think the highest-energy cosmic ray protons in the Milky Way reach a million billion electron volts, or PeV energies,” said Ke Fang, an assistant professor of physics at the University of Wisconsin, Madison. “The precise nature of their sources, which we call PeVatrons, has been difficult to pin down.”
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Trapped by chaotic magnetic fields, the particles repeatedly cross the supernova’s shock wave, gaining speed and energy with each passage. Eventually, the remnant can no longer hold them, and they zip off into interstellar space. Boosted to some 10 times the energy mustered by the world’s most powerful particle accelerator, the Large Hadron Collider, PeV protons are on the cusp of escaping our galaxy altogether, the report informed.
Astronomers have identified a few suspected PeVatrons, including one at the center of our galaxy. Supernova remnants top the list of candidates. Yet out of about 300 known remnants, only a few have been found to emit gamma rays with sufficiently high energies.