The IceCube Neutrino Observatory has a uniquely close relationship with ice. The telescope needs ice—and a lot of it—to detect the astrophysical neutrinos it was built to study. In fact, most of IceCube’s instruments are embedded in a cubic kilometer of ice at the South Pole. Construction of the detector required drilling 2.5 kilometers straight […]
Research
IceCube pipeline responds quickly to transient phenomena reported by other observatories
The IceCube Neutrino Observatory, an array of over 5,000 light sensors embedded in a cubic-kilometer of ice at the South Pole, was built to detect astrophysical neutrinos: mysterious and nearly massless particles that carry information about the most energetic events in the cosmos. Every time IceCube sees something that might be a cosmic neutrino, it […]
New IceCube analysis sets upper limits on time-dependent neutrino sources
The IceCube Collaboration searches for neutrino sources using a variety of analysis methods. In a paper submitted yesterday to The Astrophysical Journal, the collaboration describes a time-dependent all-sky scan using five years of IceCube data as well as a specific analysis of blazar 3C 279. The analyses did not reveal any new neutrino point sources. […]
Can a high-energy neutrino detector see low-energy neutrinos?
In a paper submitted recently to JCAP, the IceCube Collaboration describes a search for sub-TeV neutrino emission from astrophysical “transient” sources. This is the first transient result from IceCube to use all neutrino flavors in the 1-100 GeV energy region. In the absence of any observed sources in three years of archival IceCube data, the researchers established new limits on the volumetric rate of transients. […]
IceCube performs new measurement of all-flavor neutrino cross section
The number of neutrinos that IceCube detects is dependent on many factors, including the “neutrino cross section”: how likely it is for neutrinos to interact with nuclei in the ice. In a paper submitted today to Physical Review D, the IceCube Collaboration reports a new cross section measurement obtained by using 7.5 years of IceCube data. This is the first such measurement to incorporate all three neutrino flavors. […]
Searching for transient neutrino sources with the help of gamma rays
In a paper submitted today to The Astrophysical Journal, the AMON team, together with the IceCube and HAWC collaborations, present the analysis approach that they developed and reveal the first results from their analysis, as applied to three years of archival data from 2015 to 2018. During those three years, they identified two coincident events that met their criteria for distribution as a public alert, but there were no particularly important astronomical sources seen near either position. […]
IceCube-Gen2 will open a new window on the universe
In a white paper recently submitted to the Journal of Physics G, the international IceCube-Gen2 Collaboration outlines the need for and design of a next-generation extension of IceCube. By adding new optical and radio instruments to the existing detector, IceCube-Gen2 will increase the annual rate of cosmic neutrino observations by an order of magnitude, and its sensitivity to point sources will increase to five times that of IceCube. […]
Searching for neutrino emission from 11 LIGO-Virgo gravitational wave sources
While we have seen neutrinos and electromagnetic radiation with a common origin, researchers have yet to detect neutrinos and gravitational waves coming from the same place. So the IceCube Collaboration recently performed an analysis to look for neutrino emission that correlates with gravitational waves detected by the LIGO and Virgo Collaborations during their first two observing runs, O1 and O2. Their results are described in a paper published today in The Astrophysical Journal Letters. No coincidence was found, but the researchers are already at work on further analyses. […]
Sun’s shadow on IceCube shines light on solar magnetic field
The IceCube Collaboration recently performed an analysis to try to expand our understanding of the solar magnetic field by studying the time-dependent cosmic-ray Sun shadow. They also wanted to explore how the cosmic-ray Sun shadow changes at different energy regimes. The results, recently submitted to Physical Review D, show that more solar activity leads to a weaker Sun shadow. There were also indications that, in times of high solar activity, the shadow becomes stronger at higher energies—a hint at Sun-shadow energy dependence that will be explored more in future studies. […]
Still no sterile neutrinos, according to new IceCube analysis
In two new papers, the IceCube Collaboration updates their eV-scale sterile neutrino search using an eight-year dataset and improved event selection. The analysis found no evidence of sterile neutrinos at this energy scale and was consistent with the no-sterile-neutrino hypothesis. […]