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Neutrino Detector at the South Pole Gets Breakthrough of the Year Award

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11 December 2013

The IceCube Laboratory at the Amundsen-Scott South Pole Station, in Antarctica, hosts the computers collecting raw data. Credit: Felipe Pedreros. IceCube/NSF.

The IceCube Laboratory at the Amundsen-Scott South Pole Station, in Antarctica, hosts the computers collecting raw data. Due to satellite bandwidth allocations, the first level of reconstruction and event filtering happens in near real time in this lab. Credit: Felipe Pedreros. IceCube/NSF.

A massive astronomy telescope buried in the Antarctic ice has been given the Breakthrough of the Year award for 2013 by Physics World magazine. The telescope, the IceCube Neutrino Observatory, is a project of an international team of researchers that includes Penn State scientists.

The Antarctic observatory is honored with the award for making the first observation of cosmic neutrinos, and also for overcoming the many challenges of creating and operating a colossal detector deep under the ice at the South Pole. "The ability to detect cosmic neutrinos is a remarkable achievement that gives astronomers a completely new way of studying the cosmos," said Hamish Johnston, editor of physicsworld.com. "The judges of the 2013 award also were impressed with the IceCube collaboration's ability to build and operate a huge and extremely sensitive detector in the most remote and inhospitable place on Earth."

This is the highest-energy neutrino ever observed, with an estimated energy of 1.14 PeV. It was detected by the IceCube Neutrino Observatory at the South Pole on January 3, 2012. IceCube physicists named it Ernie. Twenty-eight events with energies around and above 30 TeV were observed in an all-sky search, conducted between May 2010 and May 2012, for high-energy neutrino events with vertices contained in the IceCube neutrino detector.Credit: IceCube Collaboration. Duration: 29 seconds.

The IceCube scientists recently announced their detection of 28 record-breaking, extremely-high-energy neutrinos -- elementary particles that likely originate outside our solar system. The achievement, nearly 25 years after the pioneering idea of detecting neutrinos in ice, provides the first solid evidence for astrophysical neutrinos from cosmic accelerators and has been hailed as the dawn of a new age of astronomy.

"While it is premature to speculate about the precise origin of these neutrinos, their energies are too high to be produced by cosmic rays interacting in the Earth's atmosphere, strongly suggesting that they are produced by distant accelerators of subatomic particles elsewhere in our galaxy, or even farther away," said Penn State Associate Professor of Physics Tyce DeYoung, the deputy spokesperson of the IceCube Collaboration. Two of these neutrinos had energies many thousands of times higher than the highest-energy neutrino that any man-made particle accelerator has ever produced.

A neutrino interacting with the ice inside the IceCube telescope produces electrically charged secondary particles that are detected thanks to a process called Cherenkov radiation. The Cherenkov light, a blue light emitted by charged particles passing through a medium at a speed greater than the speed of light in that medium, will spread through the ice over hundreds of meters. Credit: IceCube Collaboration. Duration: 21 seconds.

Penn State Professor of Physics, Astronomy, and Astrophysics Doug Cowen, who has worked on IceCube for over a decade, said "Scientists have been searching high and low for these super-energetic neutrinos using detectors buried under mountains, submerged in deep lakes and ocean trenches, lofted into the stratosphere by special balloons, and frozen into the deep clear Antarctic ice at the South Pole. To have finally seen them after all these years is immensely gratifying."

This video shows all signals observed by the IceCube detector during a period of 10 milliseconds. Most of the analyses performed by the IceCube Collaboration look for specific interactions happening in IceCube. They might be looking for very high-energy neutrinos, for example, or for neutrinos produced by cosmic rays in our atmosphere. In any case, they need to find them among the thousands of particles that reach the detector every second. Credit: IceCube Collaboration. Duration: 11 seconds.

Because high-energy neutrinos rarely interact with matter and are not deflected by magnetic fields in our galaxy, they can carry information about the workings of the highest-energy and most-distant phenomena in the universe. But although billions of neutrinos pass through the Earth every second, the vast majority are lower-energy particles that originate either in the Sun or in the Earth's atmosphere. Far rarer are the high-energy neutrinos that more likely would have been created much farther from Earth in the most powerful cosmic events -- gamma ray bursts, collisions with black holes, or the birth of stars.

Artistic rendering of IceCube digital optical modules. Credit: Jamie Yang. IceCube Collaboration.

IceCube is comprised of more than 5,000 digital optical modules melted into in a cubic kilometer of ice at the South Pole. The observatory, supported by the U.S. National Science Foundation, detects neutrinos through the fleeting flashes of blue light produced when a neutrino interacts with a water molecule in the ice. The detections of the 28 high-energy neutrino events, including two that exceeded the unprecedented energy level of 1 PeV, are among the main goals for building the IceCube detector.

The IceCube collaboration is continuing to refine and expand the search with new data and new analysis techniques, which may reveal additional high-energy events and possibly point to their astrophysical source or sources. "Although further observations will be required to confirm the extraterrestrial origin of these neutrinos, after more than ten years of work building this detector it's very exciting to see what may be the first glimpse of a new window on our universe," DeYoung said.

The IceCube Neutrino Observatory was built under a National Science Foundation (NSF) Major Research Equipment and Facilities Construction grant, with assistance from partner funding agencies in Germany, Sweden, and Belgium. Francis Halzen, the Hilldale and Gregory Breit Distinguished Professor of Physics at the University of Wisconsin-Madison, is the principal investigator of the IceCube collaboration. The NSF Division of Polar Programs continues to support the project with a Maintenance and Operations grant, in conjunction with support from international scientific funding agencies. The scientific collaboration includes 250 physicists and engineers from the U.S., Germany, Sweden, Belgium, Canada, Switzerland, Japan, New Zealand, and Australia.

CONTACTS

Doug Cowen: +1 814-863-5943, 3537 cowen@phys.psu.edu

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