Neutrino telescopes are moving steadily toward the goal of detecting astrophysical neutrinos from the most powerful galactic and extragalactic sources. Here we describe analysis methods to search for ...high energy point-like neutrino sources using detectors deep in the ice or sea. We simulate an ideal cubic kilometer detector based on real world performance of existing detectors such as AMANDA, IceCube, and ANTARES. An unbinned likelihood ratio method is applied, making use of the point spread function and energy distribution of simulated neutrino signal events to separate them from the background of atmospheric neutrinos produced by cosmic ray showers. The unbinned point source analyses are shown to perform better than binned searches and, depending on the source spectral index, the use of energy information is shown to improve discovery potential by almost a factor of two.
Recent topics of terrestrial observatories Karle, Albrecht
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2010, Volume:
623, Issue:
1
Journal Article
Peer reviewed
Ground based observatories in high energy astro-particle physics are used to explore the non-thermal high energy Universe. These detectors provide data to advance our understanding of cosmic ...accelerators of cosmic rays, gamma rays and neutrinos up to energies of 1E15eV. The detection principle is in most cases based on shower detection, mostly using photodetectors. This report gives an overview of new techniques in ground based gamma astronomy, cosmic ray air shower arrays and large under water/ice neutrino observatories.
IceCube: Construction status and first results Karle, Albrecht
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2009, Volume:
604, Issue:
1
Journal Article
Peer reviewed
Open access
IceCube is a 1
km
3 neutrino telescope currently under construction at the South Pole. The detector will consist of 4800 optical sensors deployed at depths between 1450 and 2500
m in clear Antarctic ...ice evenly distributed over 80 strings. An air shower array covering a surface area of 1
km
2 above the in-ice detector will measure cosmic ray air showers in the energy range from 300
TeV to above 1
EeV.
The detector is designed to detect neutrinos of all flavors:
ν
e,
ν
μ and
ν
τ. With 40 strings in operation in 2008, construction is 50% complete. Based on data taken to date, the observatory meets its design goals and currently exceeds the sensitivity of AMANDA and previous neutrino telescopes. The construction outlook and possible future extensions are also discussed.
We present maximum-likelihood search methods for time-dependent fluxes from point sources, such as flares or periodic emissions. We describe a method for the case when the time dependence of the flux ...can be assumed
a priori from other observations, and we additionally describe a method to search for bursts with an unknown time dependence. In the context of high energy neutrino astronomy, we simulate one year of data from a cubic kilometer scale neutrino detector and characterize these methods and equivalent binned methods with respect to the duration of neutrino emission. Compared to standard time-integrated searches, we find that up to an order of magnitude fewer events are needed to discover bursts with short durations, even when the burst time and duration are not known
a priori.
The Path from AMANDA to IceCube Karle, Albrecht
Proceedings of the International Astronomical Union,
08/2012, Volume:
8, Issue:
S288
Journal Article
Peer reviewed
Open access
In May 2011, IceCube, a neutrino telescope with one cubic kilometer instrumented volume started full operation with 5,160 sensors. The plan to build an experiment of this scale was based in part on ...the successful realization of a prototype experiment, the Antarctic Muon and Neutrino Detector Array. Here, we will review some of the major challenges and milestones.
Astrophysical neutrinos are excellent probes of astroparticle physics and high-energy physics. With energies far beyond solar, supernovae, atmospheric, and accelerator neutrinos, high-energy and ...ultra-high-energy neutrinos probe fundamental physics from the TeV scale to the EeV scale and beyond. They are sensitive to physics both within and beyond the Standard Model through their production mechanisms and in their propagation over cosmological distances. They carry unique information about their extreme non-thermal sources by giving insight into regions that are opaque to electromagnetic radiation. This white paper describes the opportunities astrophysical neutrino observations offer for astrophysics and high-energy physics, today and in coming years.
Status of IceCube in 2005 Karle, Albrecht
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2006, Volume:
567, Issue:
2
Journal Article
Peer reviewed
Open access
IceCube is a kilometer scale neutrino observatory now in construction at the South Pole. The construction started in January 2005 with the deployment of 76 sensors on the first string and four ...surface detector stations. Nine strings and 32 surface detectors are in operation since February 2006. The data based on calibration measurements, muons and artificial light flashes are consistent with performance expectations. This report focuses on design, construction experience and first data from the sensors deployed in January 2005.
Abstract
We recently reported on the radio-frequency attenuation length of cold polar ice at Summit Station, Greenland, based on bi-static radar measurements of radio-frequency bedrock echo strengths ...taken during the summer of 2021. Those data also allow studies of (a) the relative contributions of coherent (such as discrete internal conducting layers with sub-centimeter transverse scale) vs incoherent (e.g. bulk volumetric) scattering, (b) the magnitude of internal layer reflection coefficients, (c) limits on signal propagation velocity asymmetries (‘birefringence’) and (d) limits on signal dispersion in-ice over a bandwidth of ~100 MHz. We find that (1) attenuation lengths approach 1 km in our band, (2) after averaging 10 000 echo triggers, reflected signals observable over the thermal floor (to depths of ~1500 m) are consistent with being entirely coherent, (3) internal layer reflectivities are ≈–60
$\to$
–70 dB, (4) birefringent effects for vertically propagating signals are smaller by an order of magnitude relative to South Pole and (5) within our experimental limits, glacial ice is non-dispersive over the frequency band relevant for neutrino detection experiments.
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