56 research outputs found
ANTARES and other Neutrino Telescopes in the Northern Hemisphere
Several projects are concentrating their efforts on opening the high energy
neutrino window on the Universe with km-scale detectors. The detection
principle relies on the observation, using photomultipliers, of the Cherenkov
light emitted by charged leptons induced by neutrino interactions in the
surrounding detector medium. In the Northern hemisphere, while the pioneering
Baikal telescope, has been operating for 10 years, most of the activity now
concentrates in the Mediterranean sea. Recently, the Antares collaboration has
completed the construction of a 12 line array comprising ~ 900
photomultipliers. In this paper we will review the main results achieved with
the detectors currently in operation in the Northern hemisphere, as well as the
R&D efforts towards the construction of a large volume neutrino telescope in
the Mediterranean.Comment: To Appear in proceedings of the XV International Symposium on Very
High Energy Cosmic Ray Interactions (ISVHECRI 2008
Joint searches between gravitational-wave interferometers and high-energy neutrino telescopes: science reach and analysis strategies
Many of the astrophysical sources and violent phenomena observed in our
Universe are potential emitters of gravitational waves (GWs) and high-energy
neutrinos (HENs). A network of GW detectors such as LIGO and Virgo can
determine the direction/time of GW bursts while the IceCube and ANTARES
neutrino telescopes can also provide accurate directional information for HEN
events. Requiring the consistency between both, totally independent, detection
channels shall enable new searches for cosmic events arriving from potential
common sources, of which many extra-galactic objects.Comment: 4 pages. To appear in the Proceedings of the 2d Heidelberg Workshop:
"High-Energy Gamma-rays and Neutrinos from Extra-Galactic Sources",
Heidelberg (Germany), January 13-16, 200
Bounding the Time Delay between High-energy Neutrinos and Gravitational-wave Transients from Gamma-ray Bursts
We derive a conservative coincidence time window for joint searches of
gravita-tional-wave (GW) transients and high-energy neutrinos (HENs, with
energies above 100GeV), emitted by gamma-ray bursts (GRBs). The last are among
the most interesting astrophysical sources for coincident detections with
current and near-future detectors. We take into account a broad range of
emission mechanisms. We take the upper limit of GRB durations as the 95%
quantile of the T90's of GRBs observed by BATSE, obtaining a GRB duration upper
limit of ~150s. Using published results on high-energy (>100MeV) photon light
curves for 8 GRBs detected by Fermi LAT, we verify that most high-energy
photons are expected to be observed within the first ~150s of the GRB. Taking
into account the breakout-time of the relativistic jet produced by the central
engine, we allow GW and HEN emission to begin up to 100s before the onset of
observable gamma photon production. Using published precursor time differences,
we calculate a time upper bound for precursor activity, obtaining that 95% of
precursors occur within ~250s prior to the onset of the GRB. Taking the above
different processes into account, we arrive at a time window of tHEN - tGW ~
[-500s,+500s]. Considering the above processes, an upper bound can also be
determined for the expected time window of GW and/or HEN signals coincident
with a detected GRB, tGW - tGRB ~ tHEN - tGRB ~ [-350s,+150s]
Exploiting synergies between neutrino telescopes for the next galactic core-collapse supernova
Observing and characterizing the next galactic core-collapse supernova will be a critical step for neutrino experiments. Extracting information about the supernova progenitors and neutrino properties within minutes after an observation will in particular be crucial in order to optimize analysis strategies at other observatories. Moreover, certain classes of progenitors, with strong magnetic fields, could give rise to gamma-ray bursts but have been underinvestigated to date. In this contribution we propose a strategy to combine results from next-generation neutrino experiments, focusing notably on the determination of the progenitor mass and the neutrino mass ordering. Additionally, we investigate the impact of strong magnetic fields on neutrino observations, and demonstrate the detectability of the associated effects in upcoming experiments
Event reconstruction for KM3NeT/ORCA using convolutional neural networks
The KM3NeT research infrastructure is currently under construction at two
locations in the Mediterranean Sea. The KM3NeT/ORCA water-Cherenkov neutrino
detector off the French coast will instrument several megatons of seawater with
photosensors. Its main objective is the determination of the neutrino mass
ordering. This work aims at demonstrating the general applicability of deep
convolutional neural networks to neutrino telescopes, using simulated datasets
for the KM3NeT/ORCA detector as an example. To this end, the networks are
employed to achieve reconstruction and classification tasks that constitute an
alternative to the analysis pipeline presented for KM3NeT/ORCA in the KM3NeT
Letter of Intent. They are used to infer event reconstruction estimates for the
energy, the direction, and the interaction point of incident neutrinos. The
spatial distribution of Cherenkov light generated by charged particles induced
in neutrino interactions is classified as shower- or track-like, and the main
background processes associated with the detection of atmospheric neutrinos are
recognized. Performance comparisons to machine-learning classification and
maximum-likelihood reconstruction algorithms previously developed for
KM3NeT/ORCA are provided. It is shown that this application of deep
convolutional neural networks to simulated datasets for a large-volume neutrino
telescope yields competitive reconstruction results and performance
improvements with respect to classical approaches
Event reconstruction for KM3NeT/ORCA using convolutional neural networks
The KM3NeT research infrastructure is currently under construction at two locations in the Mediterranean Sea. The KM3NeT/ORCA water-Cherenkov neutrino de tector off the French coast will instrument several megatons of seawater with photosensors. Its main objective is the determination of the neutrino mass ordering. This work aims at demonstrating the general applicability of deep convolutional neural networks to neutrino telescopes, using simulated datasets for the KM3NeT/ORCA detector as an example. To this end, the networks are employed to achieve reconstruction and classification tasks that constitute an alternative to the analysis pipeline presented for KM3NeT/ORCA in the KM3NeT Letter of Intent. They are used to infer event reconstruction estimates for the energy, the direction, and the interaction point of incident neutrinos. The spatial distribution of Cherenkov light generated by charged particles induced in neutrino interactions is classified as shower-or track-like, and the main background processes associated with the detection of atmospheric neutrinos are
recognized. Performance comparisons to machine-learning classification and maximum-likelihood reconstruction algorithms previously developed for KM3NeT/ORCA are provided. It is shown that this application of deep convolutional neural networks to simulated datasets for a large-volume neutrino telescope yields competitive reconstruction results and performance
improvements with respect to classical approaches
KM3NeT - ORCA: measuring the neutrino mass ordering in the Mediterranean
International audienceORCA (Oscillations Research with Cosmics in the Abyss) is the low-energy branch of KM3NeT, the underwater Cherenkov neutrino detector in the Mediterranean. Its primary goal is to resolve the long-standing unsolved question of the neutrino mass ordering by measuring matter oscillation effects in atmospheric neutrinos. To be deployed at the French KM3NeT site, ORCA’s multi-PMT optical modules will exploit the excellent optical properties of deep seawater to reconstruct cascade and track events with a few GeV of energy. This contribution reviews the methods and technology, and discusses the current expected performances
Recent Results from the ANTARES Neutrino Telescope
International audienc
High-Energy Neutrino Searches in the Mediterranean Sea: probing the Universe with ANTARES and KM3Net-ARCA
International audienceantares is a first generation neutrino telescope, built in the deep sea. We present here its latest results, focusing on the constraints placed on the origin of the cosmic signal observed by the icecube detector. In parallel to the antares results, we discuss the expected performance of the next generation detector under construction in the Mediterranean Sea - km3net- and in particular its high-energy component arca
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