KM3NeT and ANTARES

KM3NeT is a submarine telescope for detecting astrophysical neutrino sources; ANTARES is its predecessor.

My main activities within the KM3NeT-ANTARES collaboration include

• Study of a promising new emission model of gamma ray bursts and searching for neutrinos from particularly bright gamma ray bursts with ANTARES

Gamma ray bursts (GRBs) are intense flashes of gamma rays that can last from a few milliseconds to several tens of minutes. The photospheric emission model of GRBs, although quite recent, has gained considerable interest within the international community. For this reason, I chose to study the photospheric model, which predicts high neutrino emission in a lower energy range than classical emission mechanisms.  For the first time ever within the ANTARES collaboration, I used a special sample of "raw" data recorded by the detector, which may have a higher information content, but are much more delicate to handle. The analysis developed for this study led to a significant increase in the efficiency of the detector in the energy range of interest, also thanks to a signal reconstruction algorithm that I developed specifically for this measurement. The research has allowed to set an upper limit to the number of neutrinos emitted by GRBs, both assuming the photospheric model and the classical emission models.

•  Study of the shadow of the Moon and the Sun with ANTARES and KM3NeT

Pointing accuracy and angular resolution are fundamental features of a neutrino telescope, so an accurate method to estimate them is crucial. One possibility is the measurement of the shadow of the Moon or the Sun, i.e. the deficit of atmospheric muons measured in the direction of the celestial body, which is due to the absorption of cosmic rays. I used the data collected by the ANTARES detector to show its correct pointing and directly measure its angular resolution. The shadow of the Moon was detected with a significance of 3.5 σ, while the shadow of the Sun was detected with a significance of 3.7 σ.In addition, I developed a simulation of the future KM3NeT detector to estimate the significance of the expected muon deficit.

• Estimation of the sensitivity of the KM3NeT-ARCA detector for high-energy point sources of neutrinos, search for neutrino fluxes from point sources with the ANTARES detector

The study of potential point sources of neutrinos is one of KM3NeT's main objectives. Starting from the energy spectra of photon fluxes measured by γ-ray detectors, the sensitivity of KM3NeT to these potential sources is studied. The significance of the measurement is maximised by considering the energy spectrum of the expected neutrinos and the angular extent of the source, and then deriving the measurement time required to confirm the presence of a neutrino flux from several promising sources. Several searches for neutrinos from point sources have been carried out by the KM3NeT and ANTARES collaborations

• Acoustic calibration of the KM3NeT detector with multidisciplinary applications

A system of acoustic emitter-receivers is used to reconstruct the position of all KM3NeT detector components. This calibration of the detector is of crucial importance since an accuracy of the order of 10 cm on the determination of the position of the components is necessary for a correct reconstruction of the light tracks induced by the neutrino interaction. This network of submarine microphones has also been successfully used to monitor the presence of cetaceans in the vicinity of the detector.

WHALESAFE

LIFE+ Natura 2000 WHALESAFE was a project to monitor cetaceans in an area of high maritime traffic. The position of the cetaceans is reconstructed thanks to a hydrophone system that allows the detection of cetacean vocalisations.

• Project manager of the WHALESAFE project
• Member of the Technical Coordination Committee
• Development of two cetacean position reconstruction algorithms

The first algorithm uses the triangulation of two hydrophone systems to reconstruct the position, while the second uses a single system, but exploits the reflection of sound waves on the sea surface.