The international IceCube Collaboration, which includes several researchers at Penn State, has been recognized with the 2021 Bruno Rossi Prize by the High Energy Astrophysics Division of the American Astronomical Society, the largest professional organization of astronomers in the United States. The collaboration was honored virtually at the 237th AAS Meeting “for the discovery of a high-energy neutrino flux of astrophysical origin.”
The IceCube Collaboration is made up of over 300 researchers from 53 institutions in 12 countries and is led by Francis Halzen at the University of Wisconsin–Madison. The international group maintains and operates the IceCube Neutrino Observatory, a cubic kilometer of ice at the South Pole instrumented with optical sensors that can detect signals from high-energy subatomic particles called neutrinos from outer space.
“Because neutrinos can travel for billions of light-years through space without being deflected or absorbed, they can uniquely provide accurate information about the distant universe,” said Doug Cowen, professor of physics at Penn State and a member of the collaboration. “The Penn State group in particular is involved in the analysis of a particular 'flavor' or type of neutrino, the tau neutrino, which at high energies carries the undeniable pedigree of distant astrophysical origin.”
IceCube’s first observations of high-energy cosmic neutrinos garnered the 2013 Physics World Breakthrough of the Year Award. In September 2017, IceCube detected a high-energy neutrino from the direction of a blazar called TXS 0506+056—the first-ever evidence of an extragalactic source of high-energy cosmic rays. This detection signaled a resurgence in the field of multimessenger astronomy, where scientists combine observations of light at different wavelengths and other cosmic messengers made by detectors and telescopes across the globe and in space in order to gain a more complete understanding of the universe.
“Penn State’s IceCube and AMON multimessenger teams played a critical role in developing the cyberinfrastructure that allowed the September 2017 neutrino to be converted into a real-time alert that was distributed to astronomers across the globe within seconds,” said Derek Fox, associate professor of astronomyy and astrophysics at Penn State and a member of the collaboration. “The resulting observations found the TXS 0506+056 blazar in a highly unusual state, enabling us to gather independent evidence of particle acceleration and neutrino production in this source.”
The Rossi Prize—named after Italian experimental physicist Bruno Rossi who made major contributions to particle physics and the study of cosmic rays, launched the field of X-ray astronomy, and discovered the first X-ray source, SCO X-1—is awarded “for a significant contribution to High Energy Astrophysics, with particular emphasis on recent, original work.”
“This award of the Bruno Rossi Prize is very special because it recognizes IceCube as the collaborative effort that it is,” said Halzen. “We appreciate this recognition of our scientific contributions by the astronomy community, which strengthens our resolve to continue the development of IceCube as an optimal tool for multimessenger astronomy.”
Penn State researchers who have previously received the prize include:
- Researchers involved with the LIGO collaboration in 2017 for the first direct detections of gravitational waves, for the discovery of merging black hole binaries, and for beginning the new era of gravitational-wave astronomy;
- Verne M. Willaman Professor of Astronomy & Astrophysics and Professor of Physics Niel Brandt in 2016 for leading the effort to obtain the deepest Chandra fields, enabling the most sensitive cosmological X-ray surveys to date;
- Researchers involved with the Swift collaboration in 2007 for major advances in the scientific understanding of gamma-ray bursts;
- Emeritus Holder of the Eberly Family Chair in Astronomy and Astrophysics Peter Mészáros and colleagues in 2000 for the development of theoretical models of Gamma Ray Bursters and their afterglows.