Neutrino Astronomy: Viewing the High Energy Sky Through the South Pole Glacial Ice
*note 4 p.m. start time!*
This talk will summarize recent advances in the ongoing quest to view the universe at higher energies to identify the sources of the highest energy cosmic rays and to elucidate the astrophysical mechanisms at work in these extreme objects. I explain why neutrinos, nearly massless neutral elementary particles, are the perfect “messenger” particles, which enable us to both extend the energy range at which we can view the distant universe and to unambiguously identify sources of high energy cosmic rays.
While the concept of a neutrino telescope is many decades old, the means to build such a telescope at the needed 1 cubic-kilometer scale remained technically elusive until the international IceCube collaboration successfully deployed the first such instrument in the glacial ice located at the Antarctic South Pole station. The IceCube Neutrino Observatory is comprised of over 5,000 highly sensitive photodetectors imbedded to a depth of 2.5 kilometers instrumenting a cubic kilometer of optically clear ice and began full operations in 2011. The IceCube detector has recorded neutrinos at energies over 1 PeV or about 10 15 times the energy of visible light photons, opening a new window into the high energy extreme universe for the first time. This new glimpse of the universe at these extreme energies has revealed the first ever neutrino sources, and our first unambiguous detection of high energy cosmic ray sources outside our galaxy. Recently the IceCube neutrino telescope has also given us our first view of the galactic plane in neutrinos. This talk will present an overview of these results. I will close with a brief description of what these first measurements tell us about the neutrino sky, and the plans to build a next generation telescope with higher sensitivity.