The Most Energetic Light Ever Seen Just Showered Down from the Skies Above Tibet

[Judi Lynn]

By Mara Johnson-Groh, Live Science Contributor | June 26, 2019 06:33am ET

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An image of the Crab Nebula taken by the Hubble Space Telescope. Scientists recently detected the most energetic photons ever seen, and they originate in this nebula.
Credit: NASA, ESA, J. Hester, A. Loll (ASU)

High up on the Tibetan plateau, scientists just measured the most energetic light ever seen. These photons were gamma rays with energies exceeding 100 trillion electronvolts — one even had nearly 500 trillion electronvolts of energy. Previously, only photons with tens of trillions of electronvolts had been seen.

The scientists found the photons had originated in the Crab Nebula, a pulsar, or a powerful spinning supernova remnant 6,523 light-years away.

The new results were discovered with a part of the Tibetan Air Shower Array, an experiment that uses 4 million square feet (36,900 square meters) of detectors to search for high-energy particles like cosmic rays and gamma rays. When such particles hit the upper atmosphere, they create showers of secondary subatomic particles that the array detects. The rarified air over the array, which stands 14,100 feet (4,300 meters) above sea level, allows more of the secondary particles to make it to the ground. [The 12 Strangest Objects in the Universe]

By studying showers of secondary particles called muons, the scientists were able to work backwards to figure out the energy and origin of the incoming gamma rays that caused the showers. In a new paper accepted June 13 to Physical Review Letters, astronomers studying these Crab Nebula showers reported 24 events caused by photons with energies higher than 100 trillion electronvolts. By comparison, particles of visible light from our sun only have an energy of a few electronvolts.

More:
https://www.livescience.com/65795-most-energetic-photons-detected.html

[SamKnause]

1. Thanks.

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