University of Wisconsin-Madison

IceCube News Topic: Research

Multimessenger searches for sources of gravitational waves and neutrinos

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.


The Sun also casts a shadow on IceCube

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.


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

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.


Understanding inelasticity in high-energy neutrino interactions with IceCube

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.


Constraints on neutrino emission from short-lived transient sources

Constraints on neutrino emission from short-lived transient sources

In a new search for neutrino sources, the IceCube Collaboration and other collaborators have looked for short-lived transient sources, including gamma-ray bursts, core-collapse supernovae, or neutron star mergers. The search, which looked for two or more neutrinos detected within 100 seconds from the same location, included transients that might not emit gamma rays and might be pointing to uncharted objects in the universe. The results submitted this week to Physical Review Letters did not identify any individual source but did show that the number of bright short-lived transient neutrino sources must be small or they must be fairly faint.


IceCube neutrinos pass a test of a fundamental symmetry in nature

IceCube neutrinos pass a test of a fundamental symmetry in nature

A new measurement of the IceCube Collaboration has put Lorentz symmetry to the test and found—yet again—that neutrinos behave as expected. The results, published in Nature Physics, are the most stringent limits to date in the neutrino sector on the existence of a Lorentz violating field.


IceCube neutrinos point to long-sought cosmic ray accelerator

IceCube neutrinos point to long-sought cosmic ray accelerator

Observations made by the IceCube Neutrino Observatory at the Amundsen–Scott South Pole Station and confirmed by telescopes around the globe and in Earth’s orbit have for the first time provided evidence for a known blazar as a source of high-energy neutrinos. These results are presented in two papers published this week in the journal Science.


Heavy dark matter and PeV neutrinos: are they related?

Heavy dark matter and PeV neutrinos: are they related?

The IceCube Collaboration has tested a few models of heavy dark matter and found no evidence that the high-energy neutrinos can be attributed to the decay of dark matter particles. This nondetection resulted in a new lower limit for the lifetime of dark matter particles with a mass of 10 TeV or above. The paper summarizing these results has just been submitted to the European Physical Journal C.



A boost to precision measurements in the neutrino sector

A boost to precision measurements in the neutrino sector

With better and larger neutrino telescopes on the horizon, researchers are now designing more efficient analysis techniques that will boost our understanding of neutrinos and advance searches for new physics, including additional neutrino flavors or new interactions. These techniques not only provide more accurate and robust results but also reduce expenses and time in computation that could limit improvements in the design of new detectors or the discovery potential of existing facilities. Details of these new techniques are given in a paper by the IceCube-Gen2 Collaboration submitted this week to Computer Physics Communications.


Do fast radio bursts emit high-energy neutrinos?

Do fast radio bursts emit high-energy neutrinos?

Although fast radio bursts’ (FRBs) progenitors are supposed to be compact and perhaps catastrophic cosmic events that may also produce neutrinos, IceCube has not detected any such neutrinos that could be associated with a known FRB in six years of data. These results are far from precluding the eventual detection of neutrinos from FRBs in the future, but they have set the best limits yet on how many are emitted. The results have been submitted today to ''The Astrophysical Journal''.


A first look at how the Earth stops high-energy neutrinos in their tracks

A first look at how the Earth stops high-energy neutrinos in their tracks

Neutrinos are abundant subatomic particles that are famous for passing through anything and everything, only very rarely interacting with matter. Now, scientists have demonstrated that the Earth stops very energetic neutrinos—they do not go through everything. The study is published online today by the journal Nature.


No neutrino emission from a binary neutron star merger

No neutrino emission from a binary neutron star merger

In a joint effort by the ANTARES, IceCube, Pierre Auger, LIGO, and Virgo collaborations, scientists have searched for neutrino emission from this merger. The search looked for neutrinos in the GeV to EeV energy range and did not find any neutrino in directional coincidence with the host galaxy. The nondetection agrees well with our expectation from short GRB models of observations at a large off-axis angle, which is most likely the case for the GRB detected in conjunction with GW170817. These results have just been submitted to The Astrophysical Journal.


Looking for new physics in the neutrino sector

Looking for new physics in the neutrino sector

In a new search for nonstandard neutrino interactions, the IceCube Collaboration has tested theories that introduce heavy bosons, such as some Grand Unified Theories. The study resulted in new constraints on these models, which are among the world’s best limits for nonstandard interactions in the muon-tau neutrino sector. These results have just been submitted to Physical Review D.


Improved measurements of neutrino oscillations with IceCube

Improved measurements of neutrino oscillations with IceCube

This week, the IceCube Collaboration presents a new measurement of the oscillation parameters that for the first time is competitive with the best measurements to date. These results have just been submitted to Physical Review Letters.


Are high-energy neutrinos also produced in the Milky Way?

Are high-energy neutrinos also produced in the Milky Way?

The IceCube Collaboration presents a new search for neutrino emission associated with the galactic plane with seven years of IceCube data. The results, submitted to The Astrophysical Journal, are not conclusive but set new constraints on the possible galactic contribution.


A model-independent observation of an astrophysical neutrino flux

A model-independent observation of an astrophysical neutrino flux

The astrophysical neutrino flux observed by IceCube has been the focus of many studies, by both the IceCube Collaboration and other scientists around the world. The collaboration announces today a new study that finds an excess of muon neutrinos at energies above 126 TeV, which is compatible with recent measurements of the astrophysical neutrino flux and constitutes the first model-independent measurement of this flux. These results have been submitted recently to the European Physical Journal C.


The IC86-2017 physics run: better neutrino alerts and a brand-new monitoring system

The IC86-2017 physics run: better neutrino alerts and a brand-new monitoring system

It’s that time of the year. Down at the South Pole, our team is in the darkness of the austral winter, enjoying beautiful auroras while monitoring IceCube data taking. Up north, the team has completed all updates and checks to the new data systems running live in the IceCube Lab (ICL), sitting on top of the IceCube detector on Antarctica’s surface.


IceCube sets new best limits for dark matter searches in neutrino detectors

IceCube sets new best limits for dark matter searches in neutrino detectors

IceCube has proven to be a champion detector for indirect searches of dark matter using neutrinos. In the most recent study, the collaboration sets the best limits on a neutrino signal from dark matter particles with masses between 10 and 100 GeV. These results have recently been submitted to the European Physical Journal C.


Searching for neutrino sources with IceCube cascade events

Searching for neutrino sources with IceCube cascade events

The IceCube Collaboration presents the first search for neutrino sources using cascade events with an energy above 1 TeV. Although no significant clustering was observed, this method provides an independent technique to search for astrophysical neutrino sources. These results have just been submitted to The Astrophysical Journal.


Searching for neutrino emission from 3D-localized gravitational wave sources

Searching for neutrino emission from 3D-localized gravitational wave sources

The IceCube, ANTARES, Virgo and LIGO collaborations have joined efforts to look for neutrino emission from the second gravitational wave (GW) event as well as from a previous GW candidate. IceCube and ANTARES searched for neutrinos in temporal coincidence and from the directional constraints provided by LIGO. Within 500 seconds around the two GW signals, no neutrino events were found that come within from the signal region in either detector. These results have recently been submitted to Physical Review D.


IceCube expands GRB searches to the southern sky

IceCube expands GRB searches to the southern sky

The IceCube Collaboration presents an update to previous GRB searches and broadens the search to the Southern Hemisphere using data through May 2015. The inspection of the southern sky increases the sensitivity to the highest-energy neutrinos, which are largely absorbed before reaching IceCube after sailing through the Earth. Researchers looked for neutrino emission in conjunction with prompt gamma-ray emission from 1172 GRBs and did not find any significant correlation with neutrinos detected in IceCube. These results set the strongest constraints yet on GRBs as primary sources of UHECRs. This study has just been submitted to The Astrophysical Journal.


Multiwavelength follow-up program passes the stress test of a neutrino triplet

Multiwavelength follow-up program passes the stress test of a neutrino triplet

On February 17, 2016, IceCube detected the most significant multiplet since the start of the optical follow-up program: three neutrinos appearing within 100 seconds and consistent with a point source origin. This rare neutrino coincidence has allowed further testing of the capabilities of the IceCube follow-up program, which is able to trigger observations in near real time to search for transient sources. These results have been submitted today to the journal Astronomy & Astrophysics.


Searching for sterile neutrinos with DeepCore

Searching for sterile neutrinos with DeepCore

The IceCube Collaboration has continued the hunt for sterile neutrinos with a search using lower energy atmospheric neutrinos. This new search looked into three years of IceCube data and again has not found any hint of a light sterile neutrino. These results have been submitted today to Physical Review D.


Solar dark matter continues hiding from IceCube

Solar dark matter continues hiding from IceCube

The IceCube Collaboration has recently presented an update to the search for dark matter annihilation in the sun using the first three years of data with the completed detector. The search, which again did not find evidence of neutrinos originating from dark matter annihilations, has now improved these limits by a factor of 2 to 4. These are again the most stringent limits on the spin-dependent dark-matter–proton scattering for WIMP masses above 50 GeV. This study was submitted to the European Physical Journal C.


‘Ghost particles’ could improve understanding the universe

‘Ghost particles’ could improve understanding the universe

New measurements of neutrino oscillations, observed at the IceCube Neutrino Observatory at the South Pole, have shed light on outstanding questions regarding fundamental properties of neutrinos. These new measurements of neutrinos as they change from one type to another while they travel were presented at the American Physical Society Meeting in Washington.


Everything you always wanted to know about the IceCube detector

Everything you always wanted to know about the IceCube detector

For the first time, the IceCube Collaboration is making public every detail of the only cubic-kilometer neutrino detector to date, from a flasher board in the digital optical modules—aka DOMs—to the calibration processes that allow researchers to measure the properties of neutrinos, or to the IceCube Live website that IceCubers use to monitor what is going on in the detector. The publication, over 70 pages long, has just been submitted to the Journal of Instrumentation.


Exploring blazars as astrophysical neutrino sources

Exploring blazars as astrophysical neutrino sources

A new study from the IceCube Collaboration searched in three years of IceCube data for directional clustering of neutrinos around gamma-ray sources associated with blazars from the second Fermi-LAT AGN catalog. Although some enhancements in the observed neutrino rate from these blazars were found in the 3–30 TeV region, all of them are compatible with fluctuations of the atmospheric neutrino background. These results, recently submitted to The Astrophysical Journal, open several new analyses exploring blazars as very high energy neutrino sources.


Neutrinos and gamma rays, a partnership to explore the extreme universe

Neutrinos and gamma rays, a partnership to explore the extreme universe

IceCube’s collaborative efforts with gamma-ray, X-ray, and optical telescopes started long ago. Now, the IceCube, MAGIC and VERITAS collaborations present updates to their follow-up programs that will allow the gamma-ray community to collect data from specific sources during periods when IceCube detects a higher number of neutrinos. Details of the very high energy gamma-ray follow-up program have been submitted to the Journal of Instrumentation.


Searching for point-like sources with seven years of IceCube data

Searching for point-like sources with seven years of IceCube data

The IceCube Collaboration has just announced the results of a search for point-like sources using track-like neutrino candidates detected by IceCube over seven years, from 2008 to 2015. No source has been identified, but the sensitivity keeps improving at a fast pace and will allow IceCube to test accurate models that suggest that sources could soon be observed. These results have just been submitted to The Astrophysical Journal.


Searching for dark matter in the Earth

Searching for dark matter in the Earth

The IceCube Collaboration has expanded dark matter studies with a search for annihilations in the center of the Earth. Researchers have used one year of data—May 2011 to May 2012—and have not found an excess of neutrinos above the expected background. The results have set new limits on the annihilation rate of WIMPs in the Earth that are an order of magnitude stronger than previous results by AMANDA and that also improve the IceCube spin-independent cross section limits for a WIMP mass of 50 GeV. This study has just been submitted to The European Physical Journal C.


Exploring the possibility of detecting extragalactic supernovae with IceCube-Gen2, summer research with IceCube

Exploring the possibility of detecting extragalactic supernovae with IceCube-Gen2, summer research with IceCube

Growing up on a small, secluded hobby farm in southwestern Wisconsin, the night sky played a major role in my upbringing. Since there is almost no light pollution, the night sky was always bright and clear. In the summer months, my bedtime was determined by the time a specific satellite went over the house. Every year, my family would gather up all the blankets in the house and lay outside to watch meteor showers for hours. From a young age, I loved the idea of learning more about the stars and planets, and as I got into high school, I fell in love with physics. My original plan was to become a high school physics teacher, and I found the University of Wisconsin–River Falls (UWRF) not only has a fantastic physics program but is also involved with IceCube. I had heard about IceCube in 2013, when it won Physics World’s Breakthrough of the Year, and working for IceCube became my new goal and dream.


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

Investigating excess of neutrinos from the 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

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

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.


IceCube search for the ‘sterile neutrino’ draws a blank

IceCube search for the ‘sterile neutrino’ draws a 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.


Deciphering the cosmic muon neutrino flux in IceCube

Deciphering the cosmic muon neutrino flux in IceCube

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.


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

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

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.


IceCube aims for neutron astronomy

IceCube aims for neutron astronomy

The IceCube Collaboration presents results from a search for sources of high-energy neutrons using four years of data from IceTop, the surface detector array. Researchers have not found any evidence for astrophysical neutrons, but the results have allowed the collaboration to set new limits that constrain the possible galactic neutron sources. These results have just been submitted to the Astrophysical Journal.


Rethinking PINGU, a world-class instrument for neutrino oscillation studies

Rethinking PINGU, a world-class instrument for neutrino oscillation studies

The Precision IceCube Next Generation Upgrade (PINGU) is the proposed infill extension in a region at the center of the IceCube Neutrino Observatory that will lower the energy threshold to a few GeV, dramatically increasing both the number of GeV-scale neutrinos detected by IceCube and, more importantly, the precision with which they are measured.


Searching for dark matter using IceCube cascades

Searching for dark matter using IceCube cascades

The IceCube Collaboration presents a new search for dark matter annihilation from the galactic center and halo using cascade events, i.e., particle showers created by the interaction of electron and tau neutrinos and Z-boson mediated muon neutrinos. Scientists searched for interactions starting in the DeepCore subarray between May 2011 and May 2012 and found no neutrino excess with respect to the background-only hypothesis, which allowed them to derive upper limits on dark matter candidates with masses between 30 GeV and 10 TeV. These results have been submitted today to the European Physical Journal C.


IC86-2016, or a new physics run for IceCube

IC86-2016, or a new physics run for IceCube

“On behalf of the operations group, I’m happy to report that as of run 127950 on 2016-05-20, 20:38:47 UTC, we have started the IC86-2016 physics run.” With these words, every IceCuber learned that we were entering a new year of data for IceCube.


A first search for sterile neutrinos in IceCube

A first search for sterile neutrinos in IceCube

The IceCube Collaboration has performed two independent searches for light sterile neutrinos, both with one year of data, searching for sterile neutrinos in the energy range between approximately 320 GeV and 20 TeV. IceCube has not found any anomalous disappearance of muon neutrinos and has placed new exclusion limits on the parameter space of the 3+1 model, a scenario with only one sterile neutrino. These results have been submitted today to Physical Review Letters.


Improving searches for point sources below 100 TeV

Improving searches for point sources below 100 TeV

Today, the IceCube Collaboration presents a new technique to lower the energy threshold for neutrino detection while keeping a pointing resolution to within less than a degree. IceCube researchers have used this technique in a joint search with data from a previous analysis using throughgoing muon neutrinos. No point source has been found, but sensitivity for searches below 100 TeV has been improved by a factor of ten.


A closer look at the cosmic ray anisotropy with IceCube

A closer look at the cosmic ray anisotropy with IceCube

The IceCube Collaboration is updating the cosmic ray anisotropy maps using 318 billion cosmic-ray-induced muon events detected in IceCube between May 2009 and May 2015. The larger data sample allowed discerning new regions in the anisotropy maps, which shed some light on the physical processes that stir up the variations in the arrival direction of cosmic rays. These results have been recently submitted to The Astrophysical Journal.


A search for neutrinos in coincidence with the first gravitational wave event

A search for neutrinos in coincidence with the first gravitational wave event

The detection of the first gravitational wave (GW) event by LIGO represents one of the greatest scientific breakthroughs of recent years. After receiving the gravitational wave alert in September 2015 from the Advanced LIGO detector, the IceCube and ANTARES neutrino telescopes analyzed the data they had recorded at the same time in order to search for neutrinos that might have been emitted from the same event. Neither search identified any neutrinos that could be associated with the burst. These results set the first limits on neutrino emission from a GW transient event.


Further limits on the GRB contribution to astrophysical neutrinos and ultra-high-energy cosmic rays

Further limits on the GRB contribution to astrophysical neutrinos and ultra-high-energy cosmic rays

Today, the IceCube Collaboration announces a new search for neutrino emission from GRBs with a first-ever search that covers all flavors and the full sky. Five events were found to have a low-significance correlation with five GRBs. Consequently, the analysis places tight constraints on current models of neutrino and ultra-high-energy cosmic ray (UHECR) production in GRBs. These results have just been submitted to The Astrophysical Journal.


Improving dark matter searches with neutrino telescopes

Improving dark matter searches with neutrino telescopes

In 2013, the IceCube Collaboration published the world’s best limits on the spin-dependent cross section for weakly interacting dark matter particles. They were derived from the non-observation of annihilation into neutrinos of dark matter gravitationally trapped by the Sun.

Now, the collaboration presents a new likelihood formalism that allows easy integration of any neutrino telescope data into analyses of dark matter theories.


A search for cosmic-ray sources with IceCube, the Pierre Auger Observatory, and the Telescope Array

A search for cosmic-ray sources with IceCube, the Pierre Auger Observatory, and the Telescope Array

In a new study by the IceCube, Pierre Auger, and Telescope Array Collaborations, scientists have looked for correlations between the highest energy neutrino candidates in IceCube and the highest energy cosmic rays in these two cosmic-ray observatories. The results, submitted today to the Journal of Cosmology and Astroparticle Physics, have not found any correlation at discovery level. However, potentially interesting results have been found and will continue to be studied in future joint analyses.


ANTARES and IceCube, a first joint search for neutrino sources launches a future of further collaboration

ANTARES and IceCube, a first joint search for neutrino sources launches a future of further collaboration

New results submitted today to the Astrophysical Journal are the outcome of a combined search for neutrino point sources performed by the ANTARES and IceCube collaborations. No source has been identified, but the combined search improves the sensitivity to point sources by up to a factor of two, which delivers more stringent upper limits on the flux for the candidate sources considered in this analysis.


IceCube sets best limits for mildly relativistic magnetic monopoles

IceCube sets best limits for mildly relativistic magnetic monopoles

The IceCube Collaboration today presents a search for relativistic and mildly relativistic monopoles using two years of data. No monopole candidate was observed, but IceCube data allowed setting very stringent limits for the range of velocities studied. These results have been submitted today to European Physical Journal C.


On neutrino oscillations

On neutrino oscillations

Neutrino physicists spend a lot of time in the dark. As a figurative statement this reflects how difficult neutrinos are to understand, but it also reveals the literal sense that we work with experiments that do not see a lot of sun—and it’s not just the South Pole, it’s also in mines, tunnels, and deep underwater in seas and lakes. But just like a rare neutrino interaction, every so often a brief flash of light offers some new truth about the nature of our universe.


A summer of Antarctic research at UWRF

A summer of Antarctic research at UWRF

The Physics Department of UW–River Falls hosts summer internships for young college students that allow them to engage in IceCube and other polar science projects. Over the 10-week internship, they become a member of the team, where they learn to program and to tackle challenging scientific questions. And, as you will read here, they also get a chance to share their experience.


The tau neutrino hunt is now in full swing

The tau neutrino hunt is now in full swing

Today the IceCube Collaboration has presented a search for tau neutrinos at energies above 214 TeV that, although it did not find any events, allowed setting upper limits on the astrophysical tau neutrino flux. This search sets limits on tau neutrinos at energies three orders of magnitude lower than the energies reached by previous dedicated tau neutrino searches. And more importantly, the results now submitted to Physical Review D also prove that tau neutrino searches in IceCube are reaching the sensitivity for a potential discovery.


Search for transient astrophysical neutrino emission using GeV muon neutrinos in IceCube

Search for transient astrophysical neutrino emission using GeV muon neutrinos in IceCube

In a paper submitted today to the Astrophysical Journal, the IceCube Collaboration presents results of a search for astrophysical sources of transient neutrino emission using a sample of low-energy—30 to 300 GeV—muon neutrino events from DeepCore. Although no source is singled out, the study sets limits on soft-spectra models, such as energetic or nearby choked GRBs.



IceCube summer research experience with scientists at Ruhr Universität Bochum

IceCube summer research experience with scientists at Ruhr Universität Bochum

International Research Experiences for Students (IRES) is a program funded by the National Science Foundation to support active participation of US undergraduates in international research projects. Laura Lusardi from New Richmond, WI, and Kelsey Kolell from Fond du Lac, WI, participated in the IRES program through UW–River Falls to work on IceCube research for the summer.

We are both third-year undergraduate students, studying physics at the University of Wisconsin–River Falls. This summer, we had the wonderful opportunity to travel to Germany through IRES to work with IceCube researchers. Even though we both ended up attending the same university, we took wildly different paths to get here.


Exploring new directions with DM-Ice and IceCube coincident events

Exploring new directions with DM-Ice and IceCube coincident events

When I came to Yale three years ago, I did not expect to major in physics. Yet, after taking my first class in the subject, it was not long before its fundamental nature and incredible universality had reeled me in for good. Since then, I have sought out opportunities to explore the field and learn what it really means to be a physicist. I joined Assistant Professor Reina Maruyama’s lab this past January and a few months later found myself working on DM-Ice and IceCube. Now, as I gear up for my final year of college, I am spending my summer on campus, conducting research on coincident muon events between the enormous IceCube (1 cubic km) and comparatively miniature (2,309 cubic cm) DM-Ice17 detectors.


IceCube confirms the astrophysical nature of high-energy neutrinos with an independent search in the Northern Hemisphere

IceCube confirms the astrophysical nature of high-energy neutrinos with an independent search in the Northern Hemisphere

Today, the IceCube Collaboration announces a new observation of high-energy neutrinos that originated beyond our solar system. This study, which looked for neutrinos coming from the Northern Hemisphere, confirms their cosmic origin as well as the presence of extragalactic neutrinos and the intensity of the neutrino rate. The first evidence for astrophysical neutrinos was announced by the collaboration in November 2013. The results published now in ''Physical Review Letters'' are the first independent confirmation of this discovery.


AMON, the Astrophysical Multimessenger Observatory Network

AMON, the Astrophysical Multimessenger Observatory Network

The Astrophysical Multimessenger Observatory Network (AMON) will link existing and future high-energy astrophysical observatories into a single virtual system, enabling near real-time coincidence searches for multimessenger astrophysical transients and their electromagnetic counterparts and providing alerts to follow-up observatories.


A combined analysis of the astrophysical neutrino flux in IceCube

A combined analysis of the astrophysical neutrino flux in IceCube

The IceCube Collaboration is now revisiting these results in a combined analysis accepted for publication in The Astrophysical Journal. The analysis is based on the results of six individual studies and uses up to three observables—energy, zenith angle and event topology—to derive improved constraints on the energy spectrum and the composition of neutrino flavors of the astrophysical neutrino flux.


What the atmospheric muon flux in IceCube can tell us about cosmic rays, or even about particle interactions

What the atmospheric muon flux in IceCube can tell us about cosmic rays, or even about particle interactions

In a new study presented a few days ago, the IceCube Collaboration reports the potential of atmospheric muons detected in IceCube to help our understanding of important properties of cosmic rays in a wide range of energies. These muons are also shown to be useful for investigating systematic uncertainties in neutrino studies in IceCube. Measurements of the composition of primary cosmic rays, the high-energy spectrum of muons, and the prompt flux are three of the highlights of this paper, which was submitted last Friday to Astroparticle Physics.


An IceCube neutrino alert triggers the discovery of a supernova

An IceCube neutrino alert triggers the discovery of a supernova

On March 30, 2012, IceCube detected two high-energy neutrino events. IceCube immediately sent an alert to several optical and X-ray telescopes—the Robotic Optical Transient Search Experiment (ROTSE), the Palomar Transient Factory (PTF) and the Swift satellite—and a core-collapse supernova was discovered in the PTF images. However, physicists have shown that this was a coincidental discovery and that this supernova is not likely to be the source of the neutrinos in IceCube. These results have been submitted today to the Astrophysical Journal and are the outcome of a joint study between the IceCube Collaboration and members of the PTF Collaboration, the Swift Collaboration and the Pan-STARRS1 Science Consortium.


A search for dark matter in the galactic center

A search for dark matter in the galactic center

In a new analysis of the IceCube Collaboration, a search for dark matter annihilation at the Galactic Center is presented using data from May 2010 to May 2011. The highest density of dark matter in the Milky Way is anticipated to concentrate in its center. Dark-matter self-annihilation should then produce a flux of muon neutrinos and other particles that peaks in the direction of this region, which is seen in the Southern Hemisphere by IceCube. The search did not find a neutrino excess, and the researchers have set new limits on the dark-matter self-annihilation cross section. These results have been submitted today to European Physical Journal C.


A new year of data for IceCube

A new year of data for IceCube

Not everyone begins a new year on January 1, right? That includes IceCubers, who decided a while ago that mid May would be a good time to start a new year of data for the South Pole neutrino observatory.

The IC86-2014 physics run ended on May 18, 2015, wrapping up another successful year for the IceCube detector.


A measurement of the atmospheric electron neutrino spectrum with IceCube

A measurement of the atmospheric electron neutrino spectrum with IceCube

In a new analysis by the IceCube Collaboration, the atmospheric electron neutrino spectrum is measured at energies between 0.1 TeV and 100 TeV, extending previous measurements to higher energies and yielding improved precision. The results, which have been submitted to Physical Review D, find good agreement with models of the conventional electron neutrino flux.


Latest result from neutrino observatory IceCube opens up new possibilities for particle physics

Latest result from neutrino observatory IceCube opens up new possibilities for particle physics

The South Pole observatory IceCube has recorded evidence that elusive elementary particles called neutrinos changing their identity as they travel through the Earth and its atmosphere. The observation of these neutrino oscillations, first announced in 1998 by the Super Kamiokande experiment in Japan, opens up new possibilities for particle physics with the Antarctic telescope that was originally designed to detect neutrinos from faraway sources in the cosmos.


Searches for time-dependent neutrino sources with IceCube

Searches for time-dependent neutrino sources with IceCube

Searches with IceCube have so far persistently shown us that more data is needed to reveal the first cosmic ray source. But IceCube researchers are convinced that success also requires a resolute determination to exploit IceCube data in every possible manner. In a new study submitted today to the Astrophysical Journal, the collaboration presents a search for time-dependent astrophysical neutrino sources that did not find any evidence for their existence. The study did however make it possible to set upper limits on the neutrino flux from several source candidates and has proven IceCube’s capabilities for long-term monitoring of sources triggered by multiwavelength information from several experiments.


Measuring the flavor ratio of astrophysical neutrinos

Measuring the flavor ratio of astrophysical neutrinos

In a new measurement of the flavor ratio of astrophysical neutrinos, submitted today to Physical Review Letters, the IceCube Collaboration has found good agreement with the standard source model. The collaboration also sets limits on nonstandard flavor compositions, which could be a signature for new physics in the neutrino sector, such as neutrino decay or sterile neutrinos.



Atmospheric neutrino oscillations measured with three years of IceCube data

Atmospheric neutrino oscillations measured with three years of IceCube data

Last year, an initial measurement of the neutrino oscillation parameters was a hint that IceCube could become an important detector for studying neutrino oscillations. Today, the IceCube Collaboration has submitted new results to Physical Review Letters that present an improved measurement of the oscillation parameters, via atmospheric muon neutrino disappearance, which is compatible and comparable in precision to those of dedicated oscillation experiments such as MINOS, T2K or Super-Kamiokande.


More on astrophysical neutrinos yet no track of charmed mesons

More on astrophysical neutrinos yet no track of charmed mesons

The IceCube Collaboration has expanded the search for neutrino interactions in IceCube, lowering the range of deposited energy down to 1 TeV. The goal was a better understanding of the different contributions to the neutrino flux in IceCube and hopefully to measure the charmed-meson component for the first time. The results of this study have been submitted today to Physical Review D.



A search for faint neutrino point sources in IceCube

A search for faint neutrino point sources in IceCube

In a new analysis by the IceCube Collaboration, a search for faint point sources, by looking for small-scale anisotropies in the diffuse neutrino flux, was found to be consistent with the background expectation. These results have just been submitted to Astroparticle Physics.


Multimessenger search for cosmic sources by initial LIGO-Virgo and IceCube

Multimessenger search for cosmic sources by initial LIGO-Virgo and IceCube

In a joint analysis by the IceCube, LIGO and Virgo collaborations to be submitted to the journal Physical Review D, researchers aimed to identify GW events and high-energy neutrinos that could originate from the same astrophysical source and to determine their joint significance. No significant coincident events were found, but the search allowed researchers to derive upper limits on the rate of joint sources for a range of source emission parameters.


A search for dark matter in the galactic halo

A search for dark matter in the galactic halo

The quest for galactic halo dark matter includes high-energy neutrino searches that might be produced by the self-annihilation of dark matter particles in our galaxy. If this is the case, IceCube should observe a characteristic anisotropy in the neutrino flux due to the additional dark-matter induced neutrinos. So far, the IceCube Collaboration has not found any significant deviation from the background expectation, following new results that have been submitted today to The European Physical Journal C.





IceCube sets new limits for non-relativistic magnetic monopoles

IceCube sets new limits for non-relativistic magnetic monopoles

In a new paper submitted to The European Physical Journal C, the IceCube Collaboration presents a search for non-relativistic (slow) magnetic monopoles that, despite being fruitless, has set the best experimental limits for a wide range of assumed speeds and catalysis cross sections.


IceCube looks to the future with PINGU

IceCube looks to the future with PINGU

PINGU, the Precision IceCube Next Generation Upgrade, proposes a extension inside the current IceCube array designed to measure the mass of the three known neutrino types.


IceCube awarded the 2013 Breakthrough of the Year

IceCube awarded the 2013 Breakthrough of the Year

The IceCube project has been awarded the 2013 Breakthrough of the Year by the British magazine Physics World. The Antarctic observatory has been selected for making the first observation of cosmic neutrinos, but also for overcoming the many challenges of creating and operating a colossal detector deep under the ice at the South Pole.


Neutrino telescope shines light on the last glaciation

Neutrino telescope shines light on the last glaciation

In a paper recently published in the Journal of Glaciology, the IceCube Collaboration presents a study of South Pole climate over the past 100,000 years, using high-resolution 3D laser images of the ice sheet.


Growing evidence of an astrophysical neutrino flux in IceCube: results from neutrino-induced particle showers

Growing evidence of an astrophysical neutrino flux in IceCube: results from neutrino-induced particle showers

In a new study, the IceCube Collaboration searches for neutrino-induced particle showers in one year of data taken during the construction phase of IceCube, when about half the detector was operational. Above 100 TeV, a 2.7σ excess of events was found, which is consistent with results published by the IceCube Collaboration in Science. The current paper has been submitted to the journal Physical Review D.


Looking for a diffuse flux of astrophysical muon neutrinos with IceCube

Looking for a diffuse flux of astrophysical muon neutrinos with IceCube

In an analysis published today, the IceCube Collaboration reports on a search for a diffuse astrophysical neutrino signal, looking at high-energy upward-going muon tracks, with data taken between May 2009 and May 2010, when the detector was running in its 59-string configuration. The search found a high-energy neutrino excess of 1.8σ compared to the background scenario of a pure conventional atmospheric model, a measurement consistent with the astrophysical neutrino flux described in Science. The results of this research have been submitted to Physical Review D.


IceCube pushes neutrinos to the forefront of astronomy

IceCube pushes neutrinos to the forefront of astronomy

The IceCube Neutrino Observatory is a demonstration of the power of the human passion for discovery, where scientific ingenuity meets technological innovation. Today, nearly 25 years after the pioneering idea of detecting neutrinos in ice, the IceCube Collaboration announces the observation of 28 very high-energy particle events that constitute the first solid evidence for astrophysical neutrinos from cosmic accelerators. Details of the research appear in an article published tomorrow, November 22, in Science.


Extremely high-energy neutrinos in IceCube: where do they come from?

Extremely high-energy neutrinos in IceCube: where do they come from?

The IceCube collaboration presents new results that rule out the possibility—at a confidence level greater than 90%—that the two PeV events detected in IceCube are cosmogenic neutrinos. However, the long exposure of the analyzed data, from May 2010 to May 2012, and the lack of detected events with higher energies, have allowed a new probe into the cosmogenic neutrino flux, which has been used to set the most stringent limit for the energy range from 1 PeV to 10 EeV. This analysis has just been submitted to the journal Physical Review D.


An improved muon track reconstruction in IceCube

An improved muon track reconstruction in IceCube

A new study by the IceCube Collaboration shows that the muon track reconstruction performed in the early stages of the analysis can be significantly improved by using robust statistical methods to estimate particle trajectories through the detector. The new algorithm results in a 13% gain in the angular resolution of the muon track and a 98% accuracy rate in determining the number of muons in coincident events. The paper has just been submitted to Nuclear Instruments and Methods in Physics Research Section A.


Search for neutrino emission from astrophysical sources with IceCube

Search for neutrino emission from astrophysical sources with IceCube

A search for neutrino point sources using throughgoing muons in IceCube has not found any excess of neutrinos above the atmospheric background in any given direction in the sky. Neither did dedicated searches of a priori selected objects. However, IceCube data provide insights into the nature of cosmic ray sources even from non-discovery results. These results have been submitted today to The Astrophysical Journal.


Measurement of the high-energy cosmic ray spectrum with IceTop

Measurement of the high-energy cosmic ray spectrum with IceTop

The IceCube Collaboration publishes today a new measurement of the all-particle cosmic ray energy spectrum in the energy range from 1.6 PeV to 1.3 EeV using data from IceTop, the surface component of the IceCube Neutrino Observatory. The measured spectrum exhibits clear deviations from power law behavior. These resultshave just been submitted to Physical Review D.



The cosmic-ray Moon shadow seen by IceCube

The cosmic-ray Moon shadow seen by IceCube

A recent measurement of the Moon shadow in TeV cosmic rays with the IceCube telescope sets an upper limit on the detector’s absolute pointing accuracy to 0.2 degrees. The IceCube Collaboration presents these results in a paper submitted today to Physical Review D.


First observation of high-energy neutrino oscillations by DeepCore and IceCube

First observation of high-energy neutrino oscillations by DeepCore and IceCube

The IceCube Neutrino Observatory, which comprises the IceCube and DeepCore detectors, has been designed to contribute heavily to our understanding of neutrino physics. In a paper submitted today to Physical Review Letters, the IceCube Collaboration has announced the first statistically significant detection of neutrino oscillations in the high-energy region (20–100 GeV).



IceCube reveals interesting high-energy neutrino events

IceCube reveals interesting high-energy neutrino events

From its vantage point at the geographic South Pole in Antarctica, the IceCube Neutrino Observatory is uniquely positioned to see neutrinos—mysterious, nearly massless, difficult-to-detect particles that are plentiful but little understood.



Cosmic Rays: 100 years of mystery

Cosmic Rays: 100 years of mystery

Using data from the IceCube Neutrino Observatory, astrophysicists Nathan Whitehorn and Pete Redl searched for neutrinos coming from the direction of known GRBs. And they found nothing.

Their result, appearing today in the journal Nature, challenges one of the two leading theories for the origin of the highest energy cosmic rays.


Today in Nature: Results of the GRB neutrino search

Today in Nature: Results of the GRB neutrino search

Although cosmic rays were discovered 100 years ago, their origin remains one of the most enduring mysteries in physics. Now, the IceCube Neutrino Observatory, a massive detector in Antarctica, is honing in on how the highest energy cosmic rays are produced.


The Search for Dark Matter

The Search for Dark Matter

The IceCube collaboration published a paper entitled "Search for dark matter from the Galactic halo with the IceCube Neutrino Telescope," detailing the collaboration's search for Dark Matter with IceCube.



The vanishing antineutrino

Researcher William C. Lewis discusses observed differences between neutrino and antineutrino disappearance, what that might mean for our understanding of th Universe, and the role IceCube can play in discovering an answer


Inside the Fukushima hot zone

Inside the Fukushima hot zone

IceCube collaborator and Japanese resident Shigeru Yoshida took advantage of an opportunity to help out his country by volunteering to scan residents after they spent time inside the Fukushima hot zone gathering belongings from their hastily evacuated homes. His first hand account of the area after a 9.0 magnitude earthquake compromised the nuclear power plant on March 11 is below.


IceCube sees nothing, learns something

Wired Science spoke with University of Wisconsin-Madison PhD candidate Nathan Whitehorn about what IceCube hasn't seen, and how that helps us set boundaries on what we know about the Universe.


Forschung in der Unterwelt, "Research Underground"

Forschung in der Unterwelt, "Research Underground"

This German-language publication covers the IceCube project and other neutrino detection experiments, with quotes from IceCube collaborator Christian Spiering (DESY) and advisory board member Uli Katz (U. of Erlangen).