IceCube is a cubic-kilometer Cherenkov detector located in the deep ice at the geographic South Pole. The dominant event yield in the deep ice detector consists of penetrating atmospheric muons produced in cosmic ray air showers with energies above several 100 GeV. In addition, the surface array, IceTop, deployed above the IceCube deep ice detector, measures the electromagnetic signal and low-energy muons of the air shower. Hence, IceCube and IceTop yield unique opportunities to study cosmic rays with large statistics in great detail. We discuss the latest results of air shower measurements from IceCube and IceTop, including the energy spectrum of cosmic rays from 250 TeV up to the EeV range. We will also report a measurement of the cosmic ray mass composition in the PeV to EeV range and show recent results from searches for PeV gamma ray sources in the Southern Hemisphere. In addition, results from a full-sky analysis of the cosmic ray anisotropy, using combined data from the IceCube and HAWC observatories, will be reported. Finally, we will present a measurement of the density of muons in the GeV range and discuss its consistency with predictions from hadronic interaction models.
IceCube is a cubic-kilometer Cherenkov detector in the deep ice at the geographic South Pole. The dominant event yield in the deep ice detector consists of penetrating atmospheric muons with energies above approximately 300 GeV, produced in cosmic ray air showers. In addition, the surface array, IceTop, measures the electromagnetic component and GeV muons of air showers. Hence, IceCube and IceTop yield unique opportunities to study cosmic rays with unprecedented statistics in great detail. We will present recent results of comic ray measurements from IceCube and IceTop. In this overview, we wi…
IceCube, with its surface array IceTop, detects three different components of extensive air showers: the total signal at the surface, GeV muons in the periphery of the showers and TeV muons in the deep array of IceCube. The spectrum is measured with high resolution from the knee to the ankle with IceTop. Composition and spectrum are extracted from events seen in coincidence by the surface array and the deep array of IceCube. The muon lateral distribution at the surface is obtained from the data and used to provide a measurement of the muon density at 600 meters from the shower core up to 30 Pe…
The interaction of high energy cosmic rays with the Earth's atmosphere produces extensive air showers of secondary particles with a large muon component. By exploiting the sensitivity of neutrino telescopes to high energy muons, it is possible to use these detectors for precision cosmic ray studies. The high rate of cosmic-ray muon events provides a high-statistics data sample that can be used to look for anisotropy in the arrival directions of the parent particles at the per-mille level. This paper reports on the observation of anisotropy in the cosmic ray data collected with the IceCube neut…
The IceCube Neutrino Observatory features both a kilometer-cubed detector between 1.45 and 2.45 km depth and an array of ice-filled tanks, called IceTop, located at the surface. The presence of both detectors at the same location allows for detailed studies of cosmic rays and their muon content in ice, while the lack of signals in the surface detectors can be used to identify muon tracks in the deep detector as neutrino candidates and to determine the veto efficiency of IceTop. While the solid angle coverage of the current detectors is limited, this has interesting implications for the design …
The IceCube Neutrino Observatory is a multi-component detector at the South Pole which detects high-energy particles emerging from astrophysical events. These particles provide us with insights into the fundamental properties and behaviour of their sources. Besides its principal usage and merits in neutrino astronomy, using IceCube in conjunction with its surface array, IceTop, also makes it a unique three-dimensional cosmic-ray detector. This distinctive feature helps facilitate detailed cosmic-ray analysis in the transition region from galactic to extragalactic sources. We will present the p…
We report on measurements of the all-particle cosmic ray energy spectrum and composition in the PeV to EeV energy range using three years of data from the IceCube Neutrino Observatory. The IceTop detector measures cosmic ray induced air showers on the surface of the ice, from which the energy spectrum of cosmic rays is determined by making additional assumptions about the mass composition. A separate measurement is performed when IceTop data are analyzed in coincidence with the high-energy muon energy loss information from the deep in-ice IceCube detector. In this measurement, both the spectru…
The IceCube Observatory at the South Pole is composed of a cubic kilometer scale neutrino telescope buried beneath the icecap and a square-kilometer surface water Cherenkov tank detector array known as IceTop. The combination of the surface array with the in-ice detector allows the dominantly electromagnetic signal of air showers at the surface and their high-energy muon signal in the ice to be measured in coincidence. This ratio is known to carry information about the nuclear composition of the primary cosmic rays. This paper reviews the recent results from cosmic-ray measurements performed w…
The IceCube Neutrino Observatory at the geographic South Pole consists of two components, a km2 surface array IceTop and a km3 in-ice array between 1.5 and 2.5 km below the surface. Cosmic ray events with primary energy above a few tens of TeV may trigger both the IceTop and in-ice array and leave a three-dimensional footprint of the electromagnetic and muonic components in the extensive air shower. A new reconstruction based on the minimization of a unified likelihood function involving quantities measured by both IceTop and in-ice detectors was developed. This report describes the new recons…
The IceCube Neutrino Observatory at the South Pole can provide unique tests of muon production models in extensive air showers by measuring both the low-energy (GeV) and high-energy (TeV) muon components. We present here a measurement of the TeV muon content in near-vertical air showers detected with IceTop in coincidence with IceCube. The primary cosmic-ray energy is estimated from the dominant electromagnetic component of the air shower observed at the surface. The high-energy muon content of the shower is studied based on the energy losses measured in the deep detector. Using a neural netwo…
The study of cosmic ray anisotropy in the TeV-PeV energy range could provide clues about the origin and propagation of cosmic rays in our galactic neighborhood. Because the observed anisotropy is very small, below the per-mille level, large event volumes are needed in order to characterize it in sufficient detail. Over the last six years, the IceCube Observatory has collected 150 billion cosmic ray induced muon events. This large data sample made it possible to detect anisotropies in the southern hemisphere, down to the 10$^{-5}$ level, at primary energies in excess of 10 TeV. The observed ani…
We present the current status of the IceTop air shower array on top of the IceCube neutrino detector that IceTop can use as a huge detector of TeV muons. We laos give a brief discussion of different types of air shower events that contain information on the spectrum and composition of the cosmic rays in a wide energy range.
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 …
IceAct is a proposed surface array of compact (50 cm diameter) and cost-effective Imaging Air Cherenkov Telescopes installed at the site of the IceCube Neutrino Observatory at the geographic South Pole. Since January 2019, two IceAct telescope demonstrators, featuring 61 silicon pho- tomultiplier (SiPM) pixels have been taking data in the center of the IceTop surface array during the austral winter. We present the first analysis of hybrid cosmic ray events detected by the IceAct imaging air-Cherenkov telescopes in coincidence with the IceCube Neutrino Observatory, includ- ing the IceTop surfac…
Cosmic rays and related measurements: IceTop overview; IceTop calibration; Cosmic ray composition; Air shower measurements; Studies of cosmic ray muons; Studies of PeV gamma rays; Cosmic ray anisotropy; Forbush decrease; Submitted papers to the 32nd International Cosmic Ray Conference, Beijing 2011.
We report on the measurement of the all-particle cosmic ray energy spectrum with the IceTop air shower array in the energy range from 1.58 PeV to 1.26 EeV. The IceTop air shower array is the surface component of the IceCube Neutrino Observatory at the geographical South Pole. The analysis was performed using only information from IceTop. The data used in this work were taken from June 1, 2010 to May 13, 2011. During that period the IceTop array consisted of 73 stations compared to 81 in its final configuration. The measured spectrum exhibits a clear deviation from a single power law above the …
The IceCube collaboration is building a cubic kilometer scale neutrino telescope at a depth of 2 km at the geographic South Pole, utilizing the clear Antarctic ice as a Cherenkov medium to detect cosmic neutrinos. The IceCube observatory is complemented by IceTop, a square kilometer air shower array on top of the in-ice detector. The construction of the detector is nearly finished with 79 of a planned 86 strings and 73 of 80 IceTop stations deployed. Its completion is expected in the winter 2010/11. Using data from the partially built detector, we present initial results of searches for neutri…
The IceTop air shower array is the surface component of the IceCube Neutrino Observatory at the geographic South Pole. The combination of IceTop and IceCube provides a new and powerful tool to measure cosmic ray composition in the energy range between about 300 TeV and 1 EeV by detecting the electromagnetic component at the surface in coincidence with the muon bundle in the deep underground detector. The paper will give an overview of the current status of the detector and the first physics results will be presented.
Analysis of cosmic ray surface data collected with the IceTop array of Cherenkov detectors at the South Pole provides an accurate measurement of the cosmic ray spectrum and its features in the "knee" region up to energies of about 1 EeV. IceTop is part of the IceCube Observatory that includes a deep-ice cubic kilometer detector that registers signals of penetrating muons and other particles. Surface and in-ice signals detected in coincidence provide clear insights into the nuclear composition of cosmic rays. IceCube already measured an increase of the average primary mass as a function of ener…
The IceCube Neutrino Observatory at the South Pole is a multi-component particle detector consisting of the IceTop surface array and the deep in-ice IceCube array. The foreseen enhancement of the surface instrumentation will consist of plastic scintillator panels read out by silicon photomultipliers. This additional detector component will calibrate the effect of snow accumulation on the IceTop tanks, improve the measurement of cosmic rays, and enhance the atmospheric background rejection for the high-energy astrophysical neutrino detection. Two scintillator prototype stations were deployed at…
IceTop is an air shower array that is part of the IceCube Observatory currently under construction at the geographic South Pole. When completed, it will consist of 80 stations covering an area of 1 km2. Previous analyzes done with IceTop studied the events that triggered five or more stations, leading to an effective energy threshold of about 0.5 PeV. The goal of this study is to push this threshold lower, into the region where it will overlap with direct measurements of cosmic rays which currently have an upper limit around 300TeV.We select showers that trigger exactly three or exactly four a…
IceTop is the surface instrumentation of the IceCube Neutrino Observatory at the South Pole. It is designed to measure extensive air showers of cosmic rays in the primary energy range from PeV to EeV. Air showers induced by heavier primary particles develop earlier in the atmosphere and produce more muons observable at ground level than lighter cosmic rays with the same primary energy. Therefore, the fraction of muons to all charged particles measured by IceTop characterizes the mass of primary particles. This analysis seeks a muon-based mass sensitive parameter by using the charge signal dist…
The IceCube Neutrino Observatory at the South Pole is a multi-component detector capable of measuring the cosmic ray energy spectrum and composition from PeV to EeV, the energy region typically thought to cover the transition from galactic to extragalactic sources of cosmic rays. The IceTop array at the surface is sensitive to the electromagnetic part of the air shower while the deep in-ice array detects the high-energy (TeV) muonic component of air showers. IceTop's reconstructed shower size parameter, S$_{125}$, is unfolded into a high statistics all-particle energy spectrum. Furthermore, fo…
The IceCube Neutrino Observatory with its 1-km^3 in-ice detector and the 1-km^2 surface detector (IceTop) constitutes a three-dimensional cosmic ray detector well suited for general cosmic ray physics. Various measurements of cosmic ray properties, such as energy spectra, mass composition and anisotropies, have been obtained from analyses of air showers at the surface and/or atmospheric muons in the ice.
Using IceTop, the surface component of the IceCube Neutrino Observatory, the all-particle cosmic ray energy spectrum has been determined above a few PeV. The measured energy spectrum leaves a gap of more than a decade in energy to direct measurements by balloon and satellite experiments. In this analysis, we lowered the energy threshold of IceTop to 250 TeV, narrowing the gap between IceTop and direct measurements. In order to collect lower energy events, we implemented a new trigger that uses four pairs of infill stations for which the separation between stations is less than 50 m, compared t…
IceTop, the surface array of the IceCube Neutrino Observatory, consists of 162 ice-Cherenkov tanks distributed over an area of 1km$^2$. Besides being used as a veto for the in-ice neutrino detector, IceTop is a powerful cosmic-ray detector. In the upcoming years, the capabilities of the IceTop array will be enhanced by augmenting the existing ice-Cherenkov tanks with an array of elevated scintillator panels and radio antennas. Combining the data obtained from the different detectors will improve the reconstruction of cosmic-ray energy and primary mass while reducing the energy threshold and in…
We describe the design and performance of IceTop, the air shower array on top of the IceCube neutrino detector. After the 2008/09 antarctic summer season both detectors are deployed at almost 3/4 of their design size. With the current IceTop 59 stations we can start the study of showers of energy well above 10$^{17}$ eV. The paper also describes the first results from IceTop and our plans to study the cosmic ray composition using several different types of analysis.
IceTop, the surface component of the IceCube detector, has been used to measure the energy spectrum of cosmic ray primaries in the range between 1.58 PeV and 1.26 EeV. It can also be used to study the low energy muons in air showers by looking at large distances (> 300m) from the shower axis. We will show the muon lateral distribution function at large lateral distances as measured with IceTop and discuss the implications of this measurement. We also discuss the prospects for low energy muon studies with IceTop.
The IceCube Neutrino Observatory provides the opportunity to perform unique measurements of cosmic-ray air showers with its combination of a surface array and a deep detector. Electromagnetic particles and low-energy muons ($\sim$GeV) are detected by IceTop, while a bundle of high-energy muons ($\gtrsim$400 GeV) can be measured in coincidence in IceCube. Predictions of air-shower observables based on simulations show a strong dependence on the choice of the high-energy hadronic interaction model. By reconstructing different composition-dependent observables, one can provide strong tests of had…
An upgrade of the present IceCube surface array (IceTop) with scintillation detectors and possibly radio antennas is foreseen. The enhanced array will calibrate the impact of snow accumulation on the reconstruction of cosmic-ray showers detected by IceTop as well as improve the veto capabilities of the surface array. In addition, such a hybrid surface array of radio antennas, scintillators and Cherenkov tanks will enable a number of complementary science targets for IceCube such as enhanced accuracy to mass composition of cosmic rays, search for PeV photons from the Galactic Center, or more th…
Extending large-scale air-shower arrays with radio antennas can increase the detector's performance, as the radio emission by cosmic-ray air showers provides an additional measurement of the electromagnetic component. Instrumenting the IceCube surface detector IceTop with radio detectors as well as with new particle detectors in a hybrid approach will enhance the measurement and reconstruction accuracy and allow for the characterization of highly inclined air showers. This will enable a better understanding of the atmospheric background for the in-ice neutrino measurements. It also opens the o…
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 evaluation of mass composition of cosmic rays in the knee region ($\sim 3$ PeV) is critical to understanding the transition in the origin of cosmic rays from galactic to extragalactic sources. The IceCube Neutrino Observatory at the South Pole is a multi-component detector consisting of the surface IceTop array and the deep in-ice IceCube detector. By applying modern machine-learning techniques to cosmic-ray air showers reconstructed coincidentally in both detector components of IceCube observatory, the energy and the mass of primary cosmic rays in this transition region can be measured. I…
IceTop, the surface array of IceCube, measures air showers from cosmic rays within the energy range of 1 PeV to a few EeV and a zenith angle range of up to $\approx$ 36$^\circ$. This detector array can also measure air showers arriving at larger zenith angles at energies above 20 PeV. Air showers from lighter primaries arriving at the array will produce fewer muons when compared to heavier cosmic-ray primaries. A discrimination of these muons from the electromagnetic component in the shower can therefore allow a measurement of the primary mass. A study to discriminate muons using Monte-Carlo a…
Cosmic-Ray Physics in the PeV to EeV Energy Range with the IceCube-Gen2 Surface Array (ICRC 2025)
Bartol Research Institute, Department of Physics and Astronomy, University of Delaware（特拉华大学巴托尔物理与天文学研究所）；Institute for Astroparticle Physics, Karlsruhe Institute of Technology (KIT)（卡尔斯鲁厄理工学院高能粒子物理研究所）
In May 2011, the IceCube neutrino observatory with one cubic kilometer instrumented volume started full operation with 5160 sensors on 86 strings and 324 sensors on 162 IceTop detectors. The fine-tuning of operation and calibration of the detector is still in progress while a very high uptime of well above $98\%$ is obtained. New analysis techniques rely on veto techniques for enhanced rejection of atmospheric muon and neutrino backgrounds. We will give an overview of recent results including the techniques of searching for starting tracks and some comments on the reported evidence of astrophy…
We report here an extension of the measurement of the all-particle cosmic-ray spectrum with IceTop to lower energy. The new measurement gives full coverage of the knee region of the spectrum and reduces the gap in energy between previous IceTop and direct measurements. With a new trigger that selects events in closely spaced detectors in the center of the array, the IceTop energy threshold is lowered by almost an order of magnitude below its previous threshold of 2 PeV. In this paper, we explain how the new trigger is implemented, and we describe the new machine-learning method developed to de…
In this paper we explore the possibility to complement the cosmic ray physics program of the IceCube observatory with an extended surface array of radio antennas. The combination of air-shower sampling on the surface and muon calorimetry underground offers significant scientifc potential: the neutrino sensitivity above the horizon can be enhanced by vetoing air-showers on the ground, photon-induced air-showers can be identifed by their small muon component and the coincident measurement of the particle density on the surface and the muon component gives useful information on the composition of…
The IceCube Collaboration foresees to upgrade IceTop, the present surface array, with scintillator detectors augmented by radio antennas. As one of several goals the scintillator detectors will be used to measure and mitigate the effects of snow accumulation on the IceTop tanks: the increasing energy threshold and efficiency loss are nowadays the sources of the largest systematic uncertainties in shower reconstruction and mass composition analysis. In addition, the upgrade will provide useful experience for the development of next generation neutrino detectors proposed for the South Pole. In t…
Located at the South Pole, IceCube is a particle-astrophysics observatory composed of a square-kilometer surface air shower array (IceTop) and a 1.4 km deep cubic-kilometer optical Cherenkov detector array. We review results of measurements of the cosmic ray spectrum and average mass in the energy range 1 PeV to 1 EeV.
IceCube as a three-dimensional air-shower array covers an energy range of the cosmic-ray spectrum from below 1 PeV to approximately 1 EeV. This talk is a brief review of the function and goals of IceTop, the surface component of the IceCube neutrino telescope. An overview of different and complementary ways that IceCube is sensitive to the primary cosmic-ray composition up to the EeV range is presented. Plans to obtain composition information in the threshold region of the detector in order to overlap with direct measurements of the primary composition in the 100-300 TeV range are also describ…
We present a measurement of the density of GeV muons in near-vertical air showers using three years of data recorded by the IceTop array at the South Pole. We derive the muon densities as functions of energy at reference distances of 600 m and 800 m for primary energies between 2.5 PeV and 40 PeV and between 9 PeV and 120 PeV, respectively, at an atmospheric depth of about $690\,\mathrm{g/cm}^2$. The measurements are consistent with the predicted muon densities obtained from Sibyll~2.1 assuming any physically reasonable cosmic ray flux model. However, comparison to the post-LHC models QGSJet-I…
The upgrade of IceTop, the surface array of IceCube, by a hybrid array of scintillation and radio detectors is motivated by a rich science case. The scintillators will lower the threshold for the measurement of air showers to about 100 TeV, provide a more efficient veto of air showers for neutrino measurements, and improve the separation of the electromagnetic and muonic shower components due to the different responses of scintillators and ice-Cherenkov tanks. Furthermore, the scintillators will enable the calibration and compensation of the effect of snow accumulation above IceTop. The radio …
