An international
team of scientists, including researchers at the South Dakota School of Mines & Technology,
have found
the first evidence of a source of high-energy cosmic neutrinos,
ghostly subatomic particles that can travel unhindered for billions of light
years from the most extreme environments in the
universe to Earth.
Detecting high-energy
cosmic neutrinos requires a massive particle detector, and IceCube is by
volume the world’s largest. Encompassing a cubic kilometer of deep, pristine
ice a mile beneath the surface at the South Pole, the detector is composed of
more than 5,000 light sensors arranged in a grid. When a neutrino interacts
with the nucleus of an atom, it creates a secondary charged particle, which in
turn produces a characteristic cone of blue light that is detected by IceCube
and mapped through the detector’s grid of photomultiplier tubes. Because the
charged particle along the axis of the light cone stays essentially true to the
neutrino’s direction, it gives scientists a path to follow back to the source.
The
observations, made by the IceCube Neutrino Observatory
at the U.S. Amundsen–Scott South
Pole Station and confirmed by telescopes around the globe and in Earth’s orbit,
help resolve a more than a century-o...