Performance of the KM3NeT high-energy neutrino telescope

KM3NeT is a European deep-sea research infrastructure incorporating a neutrino telescope with a volume of a few cubic kilometre at the bottom of the Mediterranean Sea. Detector response to point-like sources is presented in terms of sensitivity (flux that can be excluded at 90% CL) and discovery potential (flux that can be detected at 5σ above the background noise)

NEMO-SN1 Abyssal Cabled Observatory in the Western Ionian Sea

The NEutrinoMediterranean Observatory—Submarine Network 1 (NEMO-SN1) seafloor observatory is located in the central Mediterranean Sea, Western Ionian Sea, off Eastern Sicily (Southern Italy) at 2100-m water depth, 25 km from the harbor of the city of Catania. It is a prototype of a cabled deep-sea multiparameter observatory and the first one operating with real-time data transmission in Europe since 2005. NEMO-SN1 is also the first-established node of the European Multidisciplinary Seafloor Observatory (EMSO), one of the incoming European large-scale research infrastructures included in the Roadmap of the European Strategy Forum on Research Infrastructures (ESFRI) since 2006. EMSO will specifically address long-term monitoring of environmental processes related to marine ecosystems, marine mammals, climate change, and geohazards

GWOSC: Gravitational Wave Open Science Center

International audienceThe LIGO Scientific Collaboration and Virgo Collaboration actively pursue an open science programme. Gravitational wave strain data are publicly released through the website http://www.gw-openscience.org along with the information and tools necessary to understand and use the data. This contribution will give an overview of past and current activities related to this topic, including the recent release of the Catalog of Compact Binary Mergers (GWTC-1) and will give a sense of its impact on science, teaching and other applications

Potential of KM3NeT to observe galactic neutrino point-like sources

KM3NeT (http://www.km3net.or

Recent results from ANTARES

Operating 40 km off the coast of France since 2007, the ANTARES detector is the largest deep-sea neutrino telescope in the Northern Hemisphere with an instrumented volume of more than 0.01 cubic kilometers. It consists of an array of 885 photomultipliers detecting the Cherenkov light induced by charged leptons produced by neutrino interactions in and around the detector. The primary goal of ANTARES is to search for astrophysical neutrinos in the TeV–PeV range. This comprises generic searches for any diffuse cosmic neutrino flux as well as more specific searches for astrophysical galactic and extragalactic sources. The search program also includes multi-messenger analyses based on time and/or space coincidences with other cosmic probes. The ANTARES observatory is sensitive to a wide-range of other phenomena, from atmospheric neutrino oscillations to dark matter annihilation. In this contribution, recent results from the ANTARES neutrino telescope will be presented

Sviluppo di algoritmi di ricostruzione utilizzabili da telescopi per neutrini e risultati ottenuti con il rivelatore KM3NeT

Neutrino-astronomy is one of the most interesting frontiers of the astro-particle physics. Neutrino telescopes detect neutrinos indirectly through charged leptons produced in weak charged current interaction. In transparent media, tracks of relativistic particles can be reconstructed detecting light produced via Cherenkov effect, with 3D arrays of optical sensors. At present the most sensitive neutrino telescope in the world is the IceCube detector at the South Pole, that recently has reported evidence of a flux of cosmic high energy neutrinos exceeding the expected flux of atmospheric neutrinos by a statistically significant factor, de facto opening a new era of neutrino astronomy. KM3NeT will be the next-generation cubic kilometers scale neutrino telescope to be installed in the depths of the Mediterranean Sea. With several cubic kilometers of sea water instrumented with thousand of optical sensors, KM3NeT will be the most sensitive high energy neutrino telescope, with a sensitivity exceeding that of IceCube by a substantial factor. The construction of KM3NeT is based on a novel type of optical sensor, the Digital Optical Module, realised by arranging many small photomultipliers inside a pressure resistant glass sphere. This concept allows better performances with respect to the standard single large-area photomultiplier used in Antares and IceCube, since photon counting and directionality are possible due to photocatode segmentation. The aim of this work was to develop a new muon track reconstruction procedure appropriate for such a detector and evaluate the performances of the telescope through a complete Monte-Carlo simulation. Using this algorithm, the detector sensitivity (flux that can be excluded at 90% CL) and discovery potential (flux that can be detected at 5 sigma or 3 sigma above the background noise) for two galactic sources that appear to be the best candidates neutrino sources, the Supernova Remnants RXJ1713.7-3946 and Pulsar Wind Nebula Vela X, have been evaluated. The observation time required for the discovery of these sources at 5 sigma is about 5 year (2 years at 3 sigma) for the RXJ1713.7-3946 and about 3 years (1 year at 3sigma) for the Vela X. This analysis leads to the conclusion that at least the more intense galactic sources are at reach for KM3NeT. Recently it has been also proposed to exploit underwater Cherenkov neutrino telescopes to investigate the neutrino mass hierarchy by studying atmospheric neutrino oscillations at low energies (about 10 GeV). To perform such studies an as much as possible accurate determination of the neutrino energy and of the zenith angle are crucial. This requires a much denser array of photosensors with adequate containment conditions. First simulations show that with an effective volume of 3 Mton and an observation time of 5 years a significance of 3 sigma (5 sigma) can be achieved if the energy resolution is 25% (10%), assuming only contained events and a perfect knowledge of the muon zenith angle. To approach these assumptions an ad hoc reconstruction algorithm has been developed and is presented in this thesis. This algorithm allows to identify with an error of a few meters the interaction vertex that is used for the containment conditions. The error on the reconstructed zenith angle is less than 1 degree above about 8 GeV. The muon energy is reconstructed through the muon track length allowing to achieve a neutrino energy resolution of about 35% at 10 GeV. Further improvements are expected by including also the reconstruction of the hadronic shower, which will require a dedicated algorithm that has not yet been developed. The contamination due to electron and tau neutrino still needs to be considered

Denoising gravitational-wave signals from binary black holes with a dilated convolutional autoencoder

The broadband frequency output of gravitational-wave (GW) detectors is a non-stationary and non-Gaussian time series data stream dominated by noise populated by local disturbances and transient artifacts, which evolve on the same timescale as the GW signals and may corrupt the astrophysical information. We study a denoising algorithm dedicated to expose the astrophysical signals by employing a convolutional neural network in the encoder-decoder configuration, i.e. apply the denoising procedure of coalescing binary black hole signals to the publicly available LIGO O1 time series strain data. The denoising convolutional autoencoder neural network is trained on a dataset of simulated astrophysical signals injected into the real detector’s noise and a dataset of detector noise artifacts (‘glitches’), and its fidelity is tested on real GW events from O1 and O2 LIGO-Virgo observing runs

Pericytes of Stria Vascularis Are Targets of Cisplatin-Induced Ototoxicity: New Insights into the Molecular Mechanisms Involved in Blood-Labyrinth Barrier Breakdown

The stria vascularis (SV) contributes to cochlear homeostasis and consists of three layers, one of which contains the blood-labyrinthic barrier (BLB), with a large number of bovine cochlear pericytes (BCPs). Cisplatin is a chemotherapeutic drug that can damage the SV and cause hearing loss. In this study, cell viability, proliferation rate, cytotoxicity and reactive oxygen species production were evaluated. The protein content of phospho-extracellular signal-regulated kinases (ERK) 1/2, total ERK 1/2, phospho-cytosolic phospholipase A2 (cPLA2), total cPLA2 and cyclooxygenase 2 (COX-2) and the release of prostaglandin E2 (PGE2) and vascular endothelial growth factor (VEGF) from BCPs were analyzed. Finally, the protective effect of platelet-derived growth factor (PDGF-BB) on BCPs treated with cisplatin was investigated. Cisplatin reduced viability and proliferation, activated ERK 1/2, cPLA2 and COX-2 expression and increased PGE2 and VEGF release; these effects were reversed by Dexamethasone. The presence of PDGF-BB during the treatment with cisplatin significantly increased the proliferation rate. No studies on cell regeneration in ear tissue evaluated the effect of the PDGF/Dex combination. The aim of this study was to investigate the effects of cisplatin on cochlear pericytes and propose new otoprotective agents aimed at preventing the reduction of their vitality and thus maintaining the BLB structure