B. Baret

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 gravitational-wave (GW) transients and high-energy neutrinos (HENs, with energies & 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 highenergy photons are expected to be observed within the rst 150s of the

Multimessenger Science Reach and Analysis Method for Common Sources of Gravitational Waves and High-energy Neutrinos

We present the baseline multimessenger analysis method for the joint observations of gravitational waves (GW) and high-energy neutrinos (HEN), together with a detailed analysis of the expected science reach of the joint search. The analysis method combines data from GW and HEN detectors, and uses the blue-luminosity-weighted distribution of galaxies. We derive expected GW+HEN source rate upper limits for a wide range of source parameters covering several emission models. Using published sensitivities of externally triggered searches, we derive joint upper limit estimates both for the ongoing analysis with the initial LIGO-Virgo GW detectors with the partial IceCube detector (22 strings) HEN detector and for projected results to advanced LIGO-Virgo detectors with the completed IceCube (86 strings). We discuss the constraints these upper limits impose on some existing GW+HEN emission models.

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.

High-energy neutrino astronomy: detection methods and first achievements

In the last century, astronomy evolved from optical observation to the multi-wavelength study of celestial objects from radio waves up to x- and γ-rays, leading to a wealth of new discoveries and opening the way to high-energy astroparticle physics. In particular, the recent success of ground-based very-high-energy γ-ray telescopes has opened a new window on the most powerful and violent objects of the Universe, giving a new insight into the physical processes at work in such sources. In the context of high-energy astronomy, neutrinos constitute a unique probe since they escape from their sources, travel undisturbed on virtually cosmological distances and are produced in high-energy hadronic processes. In particular they would allow a direct detection and unambiguous identification of the sites of acceleration of high-energy baryonic cosmic rays, which remain unknown. This report discusses the physics potential of the domain and reviews the experimental techniques relevant for the detection of high-energy (≥TeV) neutrinos. The results obtained by the first generation of such detectors are presented, along with the perspectives opened by new projects and prototypes being currently developed.

Multimessenger sources of gravitational waves and high-energy neutrinos: Science reach and analysis method

Sources of gravitational waves are often expected to be observable through several messengers, such as gamma-rays, X-rays, optical, radio, and/or neutrino emission. The simultaneous observation of electromagnetic or neutrino emission with a gravitational-wave signal could be a crucial aspect for the first direct detection of gravitational waves. Furthermore, combining gravitational waves with electromagnetic and neutrino observations will enable the extraction of scientific insight that was hidden from us before. We discuss the method that enables the joint search with the LIGO-Virgo-IceCube-ANTARES global network, as well as its methodology, science reach, and outlook for the next generation of gravitational-wave detectors.

Search for signal emission from unresolved point sources with the ANTARES neutrino telescope

We use an autocorrelation analysis to look for inhomogeneities in the arrival directions of the high energy muon neutrino candidates detected by the ANTARES neutrino telescope. This approach is complementary to a point source likelihood-based search, which is mainly sensitive to one bright point like source and not to collective effects. We present the results of a search based on this two-point correlation method, providing constraints on models of a population of Active Galactic Nuclei (AGN) too faint to be detected by the likelihood-based method.

Searching for High Energy Neutrinos detected by ANTARES in coincidence with Gravitational Wave signals observed during LIGO Observation Run O1

The ANTARES Neutrino Telescope can determine the arrival direction of a muonic High Energy Neutrino (HEN) with a precision well below

The IceCube Collaboration

1^{\circ}

Joint constraints on Galactic diffuse neutrino emission from ANTARES and IceCube.

above 1 TeV. The detection of such a HEN in coincidence with a Gravitational Wave (GW) event would then improve the localization of the GW source, facilitating the search for electromagnetic counterparts. The results of such targeted HEN searches for the 3 GW events (GW150914, GW151226, both confirmed signals, and LVT151012, an event candidate) detected during the Observation Run O1 of Advanced LIGO in 2015-2016 are presented. The principles of a sub-treshold analysis, which looks for time and space correlations between HEN detected by ANTARES or IceCube and GW candidates of low signal-to-noise ratio detected by LIGO during O1 are presented. The specific procedure optimized to select HEN candidates in ANTARES data is emphasized.