Pan-STARRS1 far vision at the service of neutrino sources

In a recent publication submitted to Astronomy and Astrophysics, the IceCube Collaboration and Pan-STARRS1 scientists have searched for counterpart transient optical emission associated with IceCube high-energy neutrino alerts. When following five alerts sent during 2016-17, researchers found one supernova worth studying, SN PS16cgx. However, a more detailed analysis showed that it is most likely a Type Ia supernova, i.e., the result of a white dwarf explosion, which is not expected to produce neutrinos. […]

Read More »


Learning from blazars, a long-term neutrino–gamma-ray partnership

In a new paper by the IceCube Collaboration in partnership with scientists from the Fermi-LAT collaboration and the ASAS-SN telescopes, researchers went back to eight years of archived IceCube.

The results of this long-term search of high-energy neutrino emission from blazars confirm that this type of active galaxy cannot account for the majority of the diffuse neutrino flux seen by IceCube and that the source of most of the high-energy neutrinos is still unknown. These results have recently been submitted to Astronomy and Astrophysics. […]

Read More »


Atmospheric tau neutrino appearance in IceCube

The IceCube Collaboration has just performed its first measurement of tau neutrino appearance in oscillations of atmospheric muon neutrinos, which excluded the absence of tau neutrino oscillations at a significance of 3.2σ, confirming previous observations by OPERA and Super-Kamiokande. These results have just been submitted to the journal Physical Review D. […]

Read More »


IceCube and HAWC unite efforts to dissect the cosmic-ray anisotropy

In an attempt to better understand the anisotropy, the IceCube Neutrino Observatory and the HAWC gamma-ray observatory have united their efforts to study cosmic-ray arrival directions in both hemispheres at the same primary energy. The goal of this combined observation was to get a nearly full-sky coverage to study the propagation of cosmic rays with median energy of 10 TeV through our local interstellar medium as well as the interactions between interstellar and heliospheric magnetic fields. Results have just been accepted for publication in The Astrophysical Journal and include measurements on how the anisotropy modulations are distributed over different angular scales. […]

Read More »


A view of the Milky Way with IceCube and ANTARES

Neutrinos allow us to test our models at higher energies than do gamma rays. In a first-time effort to combine IceCube and ANTARES data to constrain galactic cosmic-ray models, scientists from both collaborations have set new limits on some of these models as well as a new limit for the galactic contribution to the IceCube neutrino flux. These results have been published this week in the journal Astrophysical Journal Letters. […]

Read More »


Steady point sources of cosmic neutrinos remain unresolved

In a new attempt to lay siege to the steady sources of neutrinos, the IceCube Collaboration has improved the search for sources in the Northern Hemisphere using muon neutrino data. The new search with eight years of IceCube data and an upgraded event selection and reconstruction resulted in enhanced sensitivity and the most stringent limits yet on emission from steady sources. These results have just been submitted to the journal European Physical Journal C . […]

Read More »


Multimessenger searches for sources of gravitational waves and neutrinos

The IceCube, LIGO, Virgo, and ANTARES collaborations have used data from the first observing period of Advanced LIGO and from the two neutrino detectors to search for coincident neutrino and gravitational wave emission from transient sources. Scientists did not find any significant coincidence. The results, recently submitted to The Astrophysical Journal, set a constraint on the density of these sources. […]

Read More »


The Sun also casts a shadow on IceCube

The IceCube Collaboration has measured the Sun’s cosmic-ray shadow for the first time, from data covering a period of five years. The results, submitted today to The Astrophysical Journal, show a clear but different shadow pattern every year. When looking at the yearly variation, scientists have found that the shadow pattern follows changes in the solar activity, which we know are correlated with the strength of the Sun’s magnetic field. Thus, this study opens a new line of research for the Antarctic neutrino observatory: the study of the Sun’s magnetic field using IceCube cosmic-ray data. […]

Read More »


The hardest search yet: cosmogenic neutrinos wait for next generation detectors

The IceCube Collaboration has, once more, looked for extremely high-energy neutrinos. And now, after analyzing nine years of IceCube data, scientists set the most stringent limits on the existence of cosmogenic neutrinos to date. As a result, the idea that ultra-high-energy cosmic rays are mostly protons is vanishing. These results were published in the journal Physical Review D last week. […]

Read More »


Understanding inelasticity in high-energy neutrino interactions with IceCube

The IceCube Collaboration has recently presented its first measurements of the neutrino inelasticity, which are also the first-ever at very high energies—from 1 TeV up to nearly 800 TeV. The inelasticity distribution was found to be in good agreement with Standard Model prediction and was later used to perform other measurements, such as charm production in neutrino interactions or flavor composition of astrophysical neutrinos. […]

Read More »