News – Page 81

Investigating excess of neutrinos from the galactic plane, summer research with IceCube

Posted on August 23, 2016 by Staff

news_feat_investigating-excess-of-neutrinos-from-galactic-plane-summer-research-with-icecube

During my summer abroad, I worked with Dr. Jon Dumm, who is searching for an excess of neutrino events originating in the plane of the Milky Way. Dr. Dumm’s analysis is designed to look for a diffuse neutrino flux from the galactic plane in agreement with a map of where pion decay is expected to occur. However, this analysis is sensitive to a neutrino flux from point sources that are not necessarily distributed as the pion decay map predicts. We simulated four possible models of cosmic-ray source density in the galaxy as proxies for possible distributions of unresolved neutrino point sources. In doing so, we established limits on the total flux from various numbers of sources to which the primary pion-decay-based analysis is sensitive. […]

Supernova filters and building an IceCube model, summer research with IceCube

Posted on August 19, 2016 by Staff

At the start of the summer, UW-River Falls student Nick Jensen and I set out to create a 1:1000 scale model of the IceCube detector using LEDs to represent DOMs. To do this, we needed a wide assortment of parts to construct the model from the ground up. We spent the first half of the summer trying to gather all the parts needed for building. […]

Week 31 at the Pole

Posted on August 17, 2016 by Jean DeMerit

The igloo from last week is finally finished. What began as an afternoon project ended up taking an entire week (well, high winds were partly to blame). In the image, you can see the igloo lit from within, and perhaps even discern that there are only few blocks missing to complete the ceiling. […]

Week 30 at the Pole

Posted on August 10, 2016 by Jean DeMerit

That’s not the IceCube Lab all frosted up in this photo but the ARO (Atmospheric Research Observatory) building, with its LIDAR beams shown shooting straight up into the sky. […]

IceCube search for the ‘sterile neutrino’ draws a blank

Posted on August 8, 2016 by Staff

news_feat_icecube-search-for-terile-neutrino-draws-blank

In an effort to fill in the blanks of the Standard Model of particle physics, science has been conducting a diligent search for a hypothesized particle known as the “sterile neutrino.” Now, with the latest results from an icy particle detector at the South Pole, scientists are almost certain that there is no such particle. […]

Week 29 at the Pole

Posted on August 2, 2016 by Jean DeMerit

Station life was quiet at the South Pole last week, but not too quiet. They celebrated Christmas in July with a special dinner. Popular in many parts of the world, for various reasons, Christmas in July is only one of numerous celebrations held throughout the year at the Pole. […]

Week 28 at the Pole

Posted on July 28, 2016 by Jean DeMerit

In summer at the South Pole, the traditional place for photo ops is the ceremonial Pole, where a mirrored sphere is mounted on a post and surrounded by a semicircular lineup of flags. But in the dark of winter, any place is as good as another as long as you have a nice aurora as backdrop […]

Deciphering the cosmic muon neutrino flux in IceCube

Posted on July 28, 2016 by Silvia Bravo

The IceCube Collaboration is now accumulating more statistics in the search for the sources of very high energy neutrinos, but also to learn more about their nature. In a new study, submitted this week to the Astrophysical Journal, the collaboration reports a substantially improved observation of the diffuse muon neutrino flux in the Northern Hemisphere using six years of IceCube data with about a tenfold increase in statistics. Once more, a clear astrophysical contribution has been found, which at the highest energies excludes a purely atmospheric origin at the 5.6 sigma level. Also, the accuracy of the measurement of the spectral properties has been improved.
[…]

Week 27 at the Pole

Posted on July 21, 2016 by Jean DeMerit

The sky was not disappointing anyone last week at the Pole; it had it all—stars, Milky Way, and auroras. Work-wise it was rather quiet for IceCube’s winterovers. But they had other activities going on, including emergency response training and showcasing their LEGO creations in a blog post for LEGO fans. […]

IceCube search for cosmogenic neutrinos favors heavy nuclei cosmic-ray sources

Posted on July 21, 2016 by Silvia Bravo

The IceCube Collaboration has made public today that a new search for cosmogenic neutrinos resulted in two very high energy neutrinos. These neutrinos, which are found to be of astrophysical origin with a 92.3% probability, include the highest energy neutrino detected to date. While of astrophysical origin, the energy of these neutrinos does not match the expectation for a cosmogenic neutrino flux. The lack of evidence for such events in a search of seven years of IceCube data places very strong constraints on the sources of UHECR. Proton-dominated sources are greatly disfavored, and testing mixed and heavy nuclei cosmic-ray sources will require much bigger instruments, such as an extension of IceCube or radio Askaryan neutrino detectors. These results have been submitted yesterday to Physical Review Letters. […]