Using the gigantic IceCube Neutrino Observatory that has instruments buried 8,000 feet beneath the ice of Antarctica, scientists confirmed the existence of cosmic neutrinos supporting earlier observations made in May 2013 of high-energy neutrinos that come from outside the solar system.
Two years ago, scientists detected several extremely high-energy neutrinos that did not seem to come from the atmosphere of the Earth. The observations suggested that the neutrally charged subatomic particles originated from outside the Solar System making them cosmic in nature.
Neutrinos are nearly massless subatomic particles with no electric charge. Because of these characteristics, detecting neutrinos is hard. The ghostly particles are only observed indirectly when they collide with other particles and produce secondary particles called muons.
The new evidence of cosmic neutrinos, which was reported in the journal Physical Review Letters on Aug. 20, is important because it paves way to a new form of astronomy using neutrinos.
"This is an excellent confirmation of IceCube's recent discoveries, opening the doors to a new era in particle physics," said Vladimir Papitashvili, from the Division of Polar Programs of the National Science Foundation (NSF), which built the detector. "And it became possible only because of extraordinary qualities of Antarctic ice and NSF's ability to successfully tackle enormous scientific and logistical problems in the most inhospitable places on Earth."
The detection of 21 ultra-high energy muons confirmed astrophysical neutrinos from the Milky Way and cosmic neutrinos originating from sources outside of our galaxy.
"Results from the IceCube Neutrino Observatory have recently provided compelling evidence for the existence of a high energy astrophysical neutrino flux utilizing a dominantly Southern Hemisphere data set consisting primarily of νe and ντ charged-current and neutral-current (cascade) neutrino interactions," researchers from the IceCube Collaboration reported.
Scientists believe that these high energy neutrinos were created inside some of the most violent phenomena in the universe. Astrophysicists want to study these particles because they hold information known to be pristine and unchanged regardless that the particles have travelled millions of light years before reaching Earth.
By studying these highest-energy neutrinos, scientists hope to gain insights into a number of Physics problems such as how nature builds the universe's powerful and efficient particle accelerators, which include the black holes, large exploding stars and the core of galaxies.
The findings are also considered meaningful because these reaffirmed the ability of the IceCube Observatory to sample neutrinos using a different technique.