[Paper Review] Searching for high-energy neutrinos in coincidence with gravitational waves with the ANTARES and VIRGO/LIGO detectors

V. Van Elewyck|arXiv (Cornell University)|Aug 17, 2009

Astrophysics and Cosmic Phenomena4 references4 citations

TL;DR

This paper proposes a multi-messenger search for high-energy neutrinos coincident with gravitational wave (GW) bursts using the ANTARES neutrino telescope and the VIRGO/LIGO GW network. By combining time, direction, and angular uncertainty data from both detectors, the method significantly reduces background noise and enables sensitive detection of rare astrophysical events, with a projected false alarm rate of ~600 yr⁻¹.

ABSTRACT

Cataclysmic cosmic events can be plausible sources of both gravitational waves (GW) and high-energy neutrinos (HEN). Both GW and HEN are alternative cosmic messengers that may escape very dense media and travel unaffected over cosmological distances, carrying information from the innermost regions of the astrophysical engines. For the same reasons, such messengers could also reveal new, hidden sources that were not observed by conventional photon astronomy. Requiring the consistency between GW and HEN detection channels shall enable new searches as one has significant additional information about the common source. A neutrino telescope such as ANTARES can determine accurately the time and direction of high energy neutrino events, while a network of gravitational wave detectors such as LIGO and VIRGO can also provide timing/directional information for gravitational wave bursts. By combining the information from these totally independent detectors, one can search for cosmic events that may arrive from common astrophysical sources.

Motivation & Objective

• To develop a coordinated analysis strategy for detecting high-energy neutrinos (HEN) in coincidence with gravitational wave (GW) bursts.
• To leverage the complementary strengths of ANTARES (neutrino timing and direction) and VIRGO/LIGO (GW timing and direction) to improve signal detection sensitivity.
• To reduce false positives by requiring consistency between independent HEN and GW detection channels.
• To constrain astrophysical emission models for cataclysmic events such as gamma-ray bursts and neutron star mergers.
• To probe hidden or opaque astrophysical sources undetectable via electromagnetic radiation.

Proposed method

• Combine time-stamped event lists from ANTARES (high-energy neutrino events) and VIRGO/LIGO (gravitational wave triggers) using a predefined, astrophysically motivated time window.
• Use angular uncertainty estimates (e.g., sky maps) to assess spatial coincidence between HEN and GW events.
• Apply an unbinned maximum likelihood method to evaluate the statistical significance of coincident events.
• Perform Monte Carlo simulations with time-shifted data streams to estimate the background rate of accidental coincidences.
• Utilize the overlap of visibility maps (approximately 4 sr, or 30% of the sky) between ANTARES and the GW network to define the effective observation window.
• Optimize signal-to-background ratio through reconstruction algorithms and quality cuts specific to each detector.

Experimental results

Research questions

• RQ1 Can a joint analysis of ANTARES and VIRGO/LIGO data detect high-energy neutrino events coincident with gravitational wave bursts from cataclysmic astrophysical sources?
• RQ2 What is the expected false alarm rate for accidental coincidences between HEN and GW events in the combined network?
• RQ3 How does the combination of independent neutrino and GW data improve background rejection and sensitivity compared to single-messenger searches?
• RQ4 To what extent can coincident detections constrain models of hadronic emission in sources like gamma-ray bursts or soft gamma-ray repeaters?
• RQ5 Can time-of-flight measurements between GW and HEN signals probe quantum gravity effects or dark energy models?

Key findings

• The joint GW+HEN search strategy maintains a very low false alarm rate of approximately 600 per year, significantly reducing background events.
• The overlap in sky visibility between ANTARES and the VIRGO/LIGO network is about 4 sr, corresponding to roughly 30% of the celestial sphere.
• Preliminary feasibility studies indicate that even with several triggers per day from each detector, the coincidence method effectively suppresses accidental coincidences.
• The method enables robust background rejection due to the independence of the two detection channels, enhancing sensitivity to rare astrophysical signals.
• The upcoming science runs (mid-2009) involving upgraded detectors (ANTARES 12L, VIRGO+ and eLIGO) will provide optimal conditions for such joint observations.
• Future next-generation detectors (KM3NeT and Advanced LIGO/Virgo) are expected to increase sensitivity by a factor of 10, further enhancing the potential for discovery.