October 27, 2022
Over the last decade, innovations in neutrino astronomy have probed the elusive interactions of neutrinos—tiny ghostly particles that can tell us about faraway astrophysical phenomena.
When neutrinos arrive from deep space, they penetrate Earth and sometimes enter ice sheets. In Greenland and at the South Pole, home to vast amounts of transparent glacial ice, the conditions are perfect for detecting traces of their behavior.
“When neutrinos interact in ice, they make a shower of particles that makes very fast blips of radio waves in the ice,” said Abigail Vieregg, a professor in the Departments of Physics and Astronomy and Astrophysics, the Enrico Fermi Institute, and the new David N. Schramm director of the Kavli Institute for Cosmological Physics.
By placing radio antennas in an array into the ice of Greenland, her experiment assembles what is called a neutrino telescope, which enables them to measure radio waves and make detailed reconstructions of how neutrinos interact.
“Neutrinos are the perfect messenger particle, meaning that if you want to look at high energy things that are far away, all the other particles those high energy things make get absorbed on their way here,” she said. “Neutrinos persist, making it all the way here, and can tell the story of what happened.”