Neutrino astronomy beyond the Sun was first imagined in the late 1950s; by the 1970s, it was realized that kilometer-scale neutrino detectors were required. The first such instrument, IceCube, is near completion and taking data. The IceCube project transforms a cubic kilometer of deep and ultra-transparent Antarctic ice into a particle detector. A total of 5,160 optical sensors are embedded into a gigaton of Antarctic ice to detect the Cherenkov light emitted by secondary particles produced when neutrinos interact with nuclei in the ice. Each optical sensor is a complete data acquisition system, including a phototube, digitization electronics, control and trigger systems and LEDs for calibration. The light patterns reveal the type (flavor) of neutrino interaction and the energy and direction of the neutrino, making neutrino astronomy possible. The scientific missions of IceCube include such varied tasks as the search for sources of cosmic rays, the observation of Galactic supernova explosions, the search for dark matter, and the study of the neutrinos themselves. These reach energies well beyond those produced with accelerator beams.
The outline of this review is as follows:
Neutrino Astronomy and Kilometer-Scale Detectors. High-Energy Neutrino Telescopes: Methodologies of Neutrino Detection. IceCube Hardware. High-Energy Neutrino Telescopes: Beyond Astronomy. Future Projects
In this paper, after a short introduction to the physics of neutrino telescopes, we will report on first performances of the IceCube detector and a selection of preliminary results obtained from data taken while IceCube operated in a partially completed configuration (22 strings and 40 strings). We will emphasize new analysis methods recently developed for the study of the Southern Hemisphere as well as for extended regions. Based on the long term experience of AMANDA and IceCube, the South Pole ice has proven to be an ideal site for astroparticle physics. New ideas and projects about the futu…
IceCube is the first representative of the km^3 class of neutrino telescopes and currently the most sensitive detector to high-energy neutrinos. Its main mission is to search for Galactic and extragalactic sources of high-energy neutrinos, but it is also an excellent detector for the investigation of a variety of other highly topical astrophysics and particle physics topics like supernovae, dark matter and neutrino oscillations. After an introduction to neutrino astronomy and neutrino telescopes, this article presents a selection of latest results from the IceCube neutrino detector with respec…
Combining observational data from multiple instruments for multi-messenger astronomy can be challenging due to the complexity of the instrument response functions and likelihood calculation. We introduce a python-based unbinned-likelihood analysis package called i3mla (IceCube Maximum Likelihood Analysis). i3mla is designed to be compatible with the Multi-Mission Maximum Likelihood (3ML) framework, which enables multi-messenger astronomy analyses by combining the likelihood across different instruments. By making it possible to use IceCube data in the 3ML framework, we aim to facilitate the us…
This overview of neutrino astronomy emphasizes observation of astrophysical neutrinos by IceCube and interesting limits on Galactic neutrinos from IceCube and ANTARES.
IceCube is a kilometer-scale high energy neutrino telescope under construction at the South Pole, a second-generation instrument expanding the capabilities of the AMANDA telescope. The scientific portfolio of IceCube includes the detection of neutrinos from astrophysical objects such as the sources of the cosmic rays, the search for dark matter, and fundamental physics using a very large data set of atmospheric neutrinos. The design and status of IceCube are briefly reviewed, followed by a summary of results to date from AMANDA and initial IceCube results from the 2007 run, with 22 of a planne…
Northern hemisphere TeV gamma-ray observatories such as Milagro and Tibet AS$γ$ have demonstrated the importance of all-sky instruments by discovering previously unidentified sources that may be the PeVatrons producing cosmic rays up to the "knee" in the cosmic ray spectrum. We evaluate the potential of IceCube to identify similar sources in the southern sky by detailing an analytic approach to determine fluxes of muons from TeV gamma-ray showers. We apply this approach to known gamma-ray sources such as supernova remnants. We find that, similar to Milagro, detection is possible in 10 years fo…
With the identification of a diffuse flux of astrophysical ("cosmic") neutrinos in the TeV-PeV energy range, IceCube has opened a new window to the Universe. However, the corresponding cosmic landscape is still uncharted: so far, the observed flux does not show any clear association with known source classes. In the present talk, I sketch the way from Baikal-NT200 to IceCube and summarize IceCube's recent astrophysics results. Finally, I describe the present projects to build even larger detectors: GVD in Lake Baikal, KM3NeT in the Mediterranean Sea and IceCube-Gen2 at the South Pole. These de…
The IceCube Neutrino Observatory is the world's largest neutrino detector, instrumenting a cubic kilometer of ice at the geographic South Pole. The detector probes neutrino energies from GeV to PeV, and collects high statistics neutrino samples by virtue of its extremely large volume. IceCube was designed to detect high-energy neutrinos from potential cosmic ray acceleration sites such as active galactic nuclei, gamma ray bursts and supernova remnants. IceCube announced the detection of a diffuse flux of astrophysical neutrinos in 2013, including the highest energy neutrinos ever detected. Ice…
Hypothesis tests based on unbinned log-likelihood (LLH) functions are a common technique used in multi-messenger astronomy, including IceCube's neutrino point-source searches. We present the general Python-based tool "SkyLLH", which provides a modular framework for implementing and executing log-likelihood functions to perform data analyses with multi-messenger astronomy data. Specific SkyLLH framework features for a new and improved time-integrated IceCube point-source analysis are highlighted, including the support for kernel density estimation (KDE) based probability density functions. In a…
The last few years, 2013-2016, the high energy neutrino events in ICECUBE and the last rich UHECR maps by AUGER and TA were hopefully opening a new High Energy astronomy age. Unfortunately the foreseen correlation between neutrino with best gamma X sources has not (yet) been found. The most celebrated GRB gamma sources do not correlate to any neutrino events. The expected Local Group anisotropy in UHECR within the nuleon GZK cut off, has just fade away. UHECR events from Virgo are almost absent. Above two hundred TeV energy tau neutrino might shine by double bang in detectable way in ICECUBE. …
The 1 km$^3$ IcCube neutrino observatory was built to find high-energy neutrinos that are associated with the sources of ultra-high energy cosmic rays. Its 5,160 optical sensors detect Cherenkov light from the charged particles produced when neutrinos interact in the ice. In this talk, I will describe the techniques that IceCube has used to search for astrophysical neutrinos. An emphasis will be given to diffuse neutrinos (not associated with a specific source), including analyses of contained events and energetic through-going neutrinos. At the end, I will discuss multi-messenger astronomy, a…
Highest energy neutrino events (contained) in cubic km ICECUBE detector resulted in last three years to be as many as $37-2=35$ signals (two of those having been recently discharged); these tens-hundred TeV (32 energetic events) up to rarest (only 3) PeV cascade showers, proved to have an extraterrestrial origin. The UHE neutrino flavor transition from a $ν_μ$ atmospheric dominance (over $ν_{e}$ showers at TeV energy), toward a higher energy shower cascade ($ν_{e}$, $ν_τ$) events at few tens TeV up to PeV energy is a hint of such a fast extraterrestrial injection. The majority (28 out of 35) o…
IceCube is a cubic-kilometer Cherenkov detector installed in deep ice at the geographic South Pole. IceCube's surface array, IceTop, measures the electromagnetic signal and mainly low-energy muons from extensive air showers above several 100 TeV primary energy, with shower bundles and high-energy muons detected by the in-ice detector IceCube. In combination, the in-ice detector and IceTop provide unique opportunities to study cosmic rays in detail with large statistics. This contribution summarizes recent results from these studies. In addition, the IceCube-Upgrade will include a considerable …
High Energy Neutrino Astronomy has been revealed by a sudden change in the flavor composition around maximal energies since three years of recording in ice km detector. However these discover didn' t led to any clear promised Neutrino Astronomy land yet. No correlation with hard gamma sources was found. Moreover the astrophysical spectra expected at Fermi value, seem to converge to a softer value, also required to avoid any Glashow resonant neutrino signal. We suggest a main solution within a composite flux ruled by prompt atmospheric neutrinos. Nevertheless the recent discover of twentyone cr…
Since 2013 IceCube cascade showers sudden overabundance have shown a fast flavor change above 30-60 TeV up to PeV energy. This flavor change from dominant muon tracks at TeVs to shower events at higher energies, has been indebted to a new injection of a neutrino astronomy. However the recent published 54 neutrino HESE, high energy starting events, as well as the 38 external muon tracks made by trough going muon formed around the IceCube, none of them are pointing to any expected X-gamma or radio sources: no one in connection to GRB, no toward active BL Lac, neither to AGN source in Fermi catal…
The announcement by the IceCube Collaboration of the observation of 28 cosmic neutrino candidates has been greeted with a great deal of justified excitement. The data reported so far depart by 4.3σfrom the expected atmospheric neutrino background, which raises the obvious question: "Where in the Cosmos are these neutrinos coming from?" We review the many possibilities which have been explored in the literature to address this question, including origins at either Galactic or extragalactic celestial objects. For completeness, we also briefly discuss new physics processes which may either explai…
The IceCube observatory located at the South Pole is a cubic-kilometre optical Cherenkov telescope primarily designed for the detection of high-energy astrophysical neutrinos. IceCube became fully operational in 2010, after a seven-year construction phase, and reached a milestone in 2013 by the first observation of cosmic neutrinos in the TeV-PeV energy range. This observation does not only mark an important breakthrough in neutrino astronomy, but it also provides a new probe of particle physics related to neutrino production, mixing, and interaction. In this review we give an overview of the …
The IceCube observatory is the first cubic kilometre scale instrument in the field of high-energy neutrino astronomy and cosmic rays. In 2009, following five successful deployment seasons, IceCube consisted of 59 strings of optical modules in the South Pole ice, together with 118 air shower detectors in the IceTop surface array. The range of physics topics includes neutrino signals from astrophysical sources, dark matter, exotic particle physics, cosmic rays, and atmospheric neutrinos. The current IceCube status and selected results are described. Anticipated future developments are also discu…
The IceCube Neutrino Observatory at the geographic South Pole instruments a gigaton of glacial Antarctic ice with over 5000 photosensors. The detector, by now running for over a decade, will be upgraded with seven new densely instrumented strings. The project focuses on the improvement of low-energy and oscillation physics sensitivities as well as re-calibration of the existing detector. Over the last few years we developed a Precision Optical Calibration Module (POCAM) providing self-monitored, isotropic, nanosecond, light pulses for optical calibration of large-volume detectors. Over 20 next…
The IceCube Neutrino Observatory instruments about 1 km$^3$ of deep, glacial ice at the geographic South Pole using 5160 photomultipliers to detect Cherenkov light from relativistic, charged particles. Most IceCube science goals rely on precise understanding and modelling of the optical properties of the instrumented ice. A peculiar light propagation effect observed by IceCube is an anisotropic attenuation, which is aligned with the local flow of the ice. Recent efforts have shown this effect is most likely due to curved photon trajectories resulting from the asymmetric light diffusion in the …
The IceCube Neutrino Observatory, located under 1.4 km of Antarctic ice, instruments a cubic kilometer of ice with 5,160 optical modules that detect Cherenkov radiation originating from neutrino interactions. The more densely instrumented center, DeepCore, aims to detect atmospheric neutrinos at 10-GeV scales to improve important measurements of fundamental neutrino properties such as the oscillation parameters and to search for non-standard interactions. Sensitivity to oscillation parameters, dependent on the distance traveled over the neutrino energy (L/E), is limited in IceCube by the resol…
The IceCube neutrino telescope discovered PeV-energy neutrinos originating beyond our Galaxy with an energy flux that is comparable to that of GeV-energy gamma rays and EeV-energy cosmic rays. These neutrinos provide the only unobstructed view of the cosmic accelerators that power the highest energy radiation reaching us from the universe. We will review the results from IceCube's first decade of operations, emphasizing the measurement of the diffuse multiflavored neutrino flux from the universe and the identification of the supermassive black hole TXS 0506+056 as a source of cosmic neutrinos …
The IceCube Neutrino Observatory has revealed the existence of sources of high-energy astrophysical neutrinos. However, identification of the sources is challenging because astrophysical neutrinos are difficult to separate from the background of atmospheric neutrinos produced in cosmic-ray-induced particle cascades in the atmosphere. The efficient detection of air showers in coincidence with detected neutrinos can greatly reduce those backgrounds and increase the sensitivity of neutrino telescopes. Imaging Air Cherenkov Telescopes (IACTs) are sensitive to gamma-ray-induced (and cosmic-ray-indu…
In light of the recent IceCube evidence for a flux of extraterrestrial neutrinos, we revisit the prospect of observing the sources of the Galactic cosmic rays. In particular, we update the predictions for the neutrino flux expected from sources in the nearby star-forming region in Cygnus taking into account recent TeV gamma ray measurements of their spectra. We consider the three Milagro sources: MGRO J2019+37, MGRO J1908+06 and MGRO J2031+41 and calculate the attainable confidence level limits and statistical significance as a function of the exposure time. We also evaluate the prospects for …
The recent association between IC-170922A and the blazar TXS0506+056 highlights the importance of real-time observations for identifying possible astrophysical neutrino sources. Thanks to its near-100\% duty cycle, 4$π$ steradian field of view, and excellent sensitivity over many decades of energy, IceCube is well suited both to generate alerts for follow-up by other instruments and to rapidly follow up alerts generated by other instruments. Detection of neutrinos in coincidence with transient astrophysical phenomena serves as a smoking gun for hadronic processes and supplies essential informa…
The IceCube Neutrino Observatory opened the window on neutrino astronomy by discovering high-energy astrophysical neutrinos in 2013 and identifying the first compelling astrophysical neutrino source, the blazar TXS0506+056, in 2017. In this talk, we will discuss the science reach and ongoing development of the IceCube-Gen2 facility---a planned extension to IceCube. IceCube-Gen2 will increase the rate of observed cosmic neutrinos by an order of magnitude, be able to detect five-times fainter neutrino sources, and extend the measurement of astrophysical neutrinos several orders of magnitude high…
The IceCube Neutrino Observatory, located at the geographic South Pole, is a Cherenkov detector that continuously monitors a cubic kilometer of instrumented glacial ice for neutrino interactions in the sub-TeV to EeV energy range. Its primary design goal is the study of powerful astrophysical objects that could act as natural particle accelerators and thus as sources of (ultra) high energy cosmic rays - in short: to do neutrino astronomy. IceCube has discovered a diffuse flux of high energy astrophysical neutrinos consistent with an extra-galactic origin. In addition the IceCube Collaboration …
The discoveries of high-energy astrophysical neutrinos by IceCube in 2013 and of gravitational waves by LIGO in 2015 have enabled a new era of multi-messenger astronomy. Gravitational waves can identify the merging of compact objects such as neutron stars and black holes. These compact mergers, especially neutron star mergers, are potential neutrino sources. We present an analysis searching for neutrinos from gravitational wave sources reported by the LIGO Virgo Collaboration (LVC). We use a dedicated transient likelihood analysis combining IceCube events with source localizations provided by …
With the recent discovery of high-energy neutrinos of extra-terrestrial origin by the IceCube neutrino observatory, neutrino-astronomy is entering a new era. This review will cover currently operating open water/ice neutrino telescopes, the latest evidence for a flux of extra-terrestrial neutrinos and current efforts in the search for steady and transient neutrino point sources. Generalised constraints on potential astrophysical sources are presented, allowing to focus the hunt for the sources of the observed high-energy neutrinos.
The search for the sources of cosmic rays is a three-fold assault, using charged cosmic rays, gamma rays and neutrinos. The first conceptual ideas to detect high energy neutrinos date back to the late fifties. The long evolution towards detectors with a realistic discovery potential started in the seventies and eighties, with the pioneering works in the Pacific Ocean close to Hawaii and in Lake Baikal in Siberia. But only now, half a century after the first concepts, such a detector is in operation: IceCube at the South Pole. We do not yet know whether with IceCube we will indeed detect extrat…
IceCube Neutrino Astronomy is considered. The tau neutrino flavor paucity and the asymmetry for the tracks suggest a dominant atmospheric charm noise. The correlated cascades and tracks asymmetry with relevant statistics enforce the charm noise dominance in the data. The charm signal may explain at once the absence of correlation for the tracks data with the galactic plane and with known brightest gamma sources.
The IceCube Neutrino Observatory, completed in December 2010 and located at the geographic South Pole, is the largest neutrino telescope in the world. IceCube includes the more densely instrumented DeepCore subarray, which increases IceCube's sensitivity at neutrino energies down to 10 GeV. DeepCore has recently demonstrated sensitivity to muon neutrino disappearance from atmospheric neutrino oscillation. A further extension is under consideration, the Precision IceCube Next Generation Upgrade (PINGU) which would lower the energy threshold below about 10 GeV. In particular, PINGU would be sens…
This report is the write-up of a rapporteur talk on neutrino astronomy given at the 34th International Cosmic Ray Conference in The Hague, Netherlands, in 2015. Here, selected contributions on the neutrino astronomy from the total of 40 talks and 90 posters presented in NU sessions at the 34th ICRC are summarized in the attempt of providing a status report on this rapidly glowing new field. The field of neutrino astronomy has recently experienced a "phase transition" since the first observation of high energy cosmic neutrinos. Extensive efforts have been made to identify the origin of the neut…
We discuss how to constrain new physics in the neutrino sector using multimessenger astronomical observations by the IceCube experiment. The information from time and direction coincidence with an identifiable source is used to improve experimental limits by constraining the mean free path of neutrinos from these sources. Over the coming years, IceCube is expected to detect neutrinos from a variety of neutrino-producing sources, and has already identified the Blazar TXS 0506+056 as a neutrino-producing source. We explore specific phenomenological models: additional neutrino interactions, neutr…
The IceCube Neutrino Observatory opened the window on high-energy neutrino astronomy by confirming the existence of PeV astrophysical neutrinos and identifying the first compelling astrophysical neutrino source in the blazar TXS0506+056. Planning is underway to build an enlarged detector, IceCube-Gen2, which will extend measurements to higher energies, increase the rate of observed cosmic neutrinos and provide improved prospects for detecting fainter sources. IceCube-Gen2 is planned to have an extended in-ice optical array, a radio array at shallower depths for detecting ultra-high-energy (>10…
Detection of 54 very high-energy (VHE) neutrinos by the IceCube Neutrino Observatory has opened a new chapter in multi-messenger astronomy. However due to large errors in measuring the directions of the neutrino shower-type events, which dominate the current event list, it is difficult to identify their astrophysical sources. We perform cross-correlation study of IceCube neutrino events with extragalactic candidate sources using X-ray and gamma-ray selected source catalogues such as Swift-BAT, 3LAC and TeV-Cat. We apply different cuts on the X-ray and gamma-ray fluxes of the sources in these c…
In 2012, physicists and astronomers celebrated the hundredth anniversary of the detection of cosmic rays by Viktor Hess. One year later, in 2013, there was first evidence for extraterrestrial high-energy neutrinos, i.e. for signal which may contain key information on the origin of cosmic rays. That evidence is provided by data taken with the IceCube neutrino telescope at the South Pole. First concepts to build a detector of this kind have been discussed at the 1973 International Cosmic Ray Conference. Nobody would have guessed at that time that the march towards first discoveries would take fo…
The IceCube Neutrino Observatory is the world's largest neutrino detector with a cubic-kilometer instrumented volume at the South Pole. It is preparing for a major upgrade that will significantly increase its sensitivity. A promising technological innovation investigated for this upgrade is wavelength shifting optics. Augmenting sensors with such optics could increase the photo-collection area of IceCube's digital optical modules, and shift the incoming photons' wavelength to where these modules are the most sensitive. Here we investigate the use of IceCube's drill holes themselves as waveleng…
The advent of Multi-Messenger Astronomy has allowed for new types of source searches within the neutrino community. We present the results of the first search for GeV astrophysical neutrinos emitted from Compact Binary Mergers, i.e. binary black hole or binary neutron star mergers, detected by the LIGO and Virgo interferometers. We introduce a new approach that lowers the energy threshold of IceCube from roughly 10 GeV to <1 GeV. This method uses an innovative event selection of GeV neutrino events in IceCube and searches for a statistically significant increase in the amount of GeV-like event…
Construction of the cubic-kilometer neutrino detector IceCube at the South Pole has been completed in December 2010. It forms a lattice of 5160 photomultiplier tubes monitoring a gigaton of the deep Antarctic ice for particle induced photons. The telescope is primarily designed to detect neutrinos with energies greater than 100 GeV from astrophysical sources. Beyond this astrophysical motivation IceCube is also a discovery instrument for the search for physics beyond the Standard Model. Owing to subfreezing ice temperatures, the photomultiplier dark noise rates are particularly low which opens…
Between 2011 March and 2014 August Swift responded to 20 triggers from the IceCube neutrino observatory, observing the IceCube 50% confidence error circle in X-rays, typically within 5 hours of the trigger. No confirmed counterpart has been detected. We describe the Swift follow up strategy and data analysis and present the results of the campaign. We discuss the challenges of distinguishing the X-ray counterpart to a neutrino trigger from serendipitous uncatalogued X-ray sources in the error circle, and consider the implications of our results for future strategies for multi-messenger astrono…
The IceCube Neutrino Observatory instruments about 1 km^3 of deep, glacial ice at the geographic South Pole with 5160 photomultipliers to detect Cherenkov light from charged relativistic particles. The experiment pursues a wide range of scientific questions ranging from particle physics such as neutrino oscillations to high-energy neutrino astronomy. Most of these efforts rely heavily on an ever more precise understanding of the optical properties of the instrumented ice. An unexpected light propagation effect, observed by the experiment, is an anisotropic attenuation, which is aligned with th…
With the completion of the first cubic-kilometer class neutrino telescopes, IceCube, the race for the discovery of the first cosmic high-energy neutrino sources enters into a new phase. The usage of neutrinos as cosmic messengers has the potential to significantly enhance and extend our knowledge on Galactic and extragalactic sources of the high-energy universe. This article gives a short review on the status of neutrino telescopes and their sensitivities concentrating on point-like sources. It discusses the current upper limits on neutrino emissions and their implications for models of differ…
The IceCube Neutrino Observatory instruments about 1 km$^3$ of deep, glacial ice at the geographic South Pole using 5160 photomultipliers to detect Cherenkov light of charged relativistic particles. Most of IceCube's science goals rely heavily on an ever more precise understanding of the optical properties of the instrumented ice. A curious light propagation effect observed by the experiment is an anisotropic attenuation, which is aligned with the local flow of the ice. Having recently identified curved photon trajectories resulting from asymmetric light diffusion in the birefringent polycryst…
Neutrino astronomy has entered an exciting time with the completion of the first km3-scale neutrino telescope at the South Pole (IceCube) and the successful operation of the first under-sea neutrino telescope in the Mediterranean (Antares). This new generation of experiments is approaching the sensitivity levels required to explore at least part of the current landscape of neutrino flux predictions from astrophysical sources, bringing neutrino astronomy on the verge of its first discovery. This contribution presents the current status and latest results of the operating neutrino telescopes, wi…
Neutrinos produced in dark matter self-annihilations in the Galactic halo might be detectable by IceCube. We present a search for such a signal using the IceCube detector in the 22-string configuration. We first evaluate the sensitivity before presenting the result based on the collected data. We find that even with the partially instrumented detector and a small dataset, we are able to meaningfully constrain the dark matter self-annihilation cross-section. Future analyses, based on data sets from a larger detector and the inclusion of the Galactic center, are expected to considerably improve …
We discuss the status of the kilometer-scale neutrino detector IceCube and its low energy upgrade Deep Core and review its scientific potential for particle physics. We subsequently appraise IceCube's potential for revealing the enigmatic sources of cosmic rays. After all, this aspiration set the scale of the instrument. While only a smoking gun is missing for the case that the Galactic component of the cosmic ray spectrum originates in supernova remnants, the origin of the extragalactic component remains as inscrutable as ever. We speculate on the role of the nearby active galaxies Centaurus …
First evidence of high-energy astrophysical neutrino observation with the IceCube detector from May 2010 to May 2012 is presented. Selecting for high-energy neutrino events with vertices well contained in the detector volume, the analysis has sensitivity starting at approximately 50 TeV, and the highest energy events are a few PeV. A significant excess in flux is observed above expected backgrounds from atmospheric muons and neutrinos. The sample of 28 events includes the highest energy neutrinos ever observed, and has properties consistent in flavor, arrival direction, and energy with generic…
