Stacked search for time shifted high energy neutrinos from gamma ray bursts with the Antares neutrino telescope

Abstract

A search for high-energy neutrino emission correlated with gamma-ray bursts outside the electromagnetic prompt-emission time window is presented. Using a stacking approach of the time delays between reported gammaray burst alerts and spatially coincident muon-neutrino signatures, data from the Antares neutrino telescope recorded between 2007 and 2012 are analysed. One year of public data from the IceCube detector between 2008 and 2009 have been also investigated. The respective timing profiles are scanned for statistically significant accumulations within 40 days of the Gamma Ray Burst, as expected from Lorentz Invariance Violation effects and some astrophysical models. No significant excess over the expected accidental coincidence rate could be found in either of the two data sets. The average strength of the neutrino signal is found to be fainter than one detectable neutrino signal per hundred gamma-ray bursts in the Antares data at 90% confidence level.

New constraints on all flavor Galactic diffuse neutrino emission with the ANTARES telescope

“…The analysis presented in this work is based on a likelihood ratio test, widely used in neutrino astronomy, e.g. in the search for neutrinos from individual point-like or extended sources by ANTARES [28,29,30,31]. It is adapted here to a full-sky search where the signal map is built according to the reference models mentioned above.…”

New Constraints on all flavour Galactic diffuse neutrino emission with the ANTARES telescope

“…This analysis relies on a likelihood ratio test, similar to the one used in the search for neutrinos from individual point-like or extended sources by ANTARES [14,15,16,17]. It is adapted here to a full-sky search where the signal map is built according to the reference models mentioned above.…”

Can the gamma-ray bursts travelling through the interstellar space be explained without invoking the drastic assumption of Lorentz invariance violation?

“…Assuming that a GRB and the corresponding neutrino burst are produced at the same time or within a short period, a significant delay would indicate that the electromagnetic and neutrino signals have travelled at different speeds. Note, however, that the recent experimental studies show only faint neutrino signals associated with GRB [2,3], and hence the observed delays may be inaccurate.…”

“…Those events may also produce high-energy cosmic rays and consequently bursts of high-energy neutrinos [1]. Neutrino bursts have been observed to be shifted in time with respect to the GRB (see [2,3] and references therein). The time window = − between the arrival times of a GRB and a neutrino burst can vary between an hour or several days.…”

“…Consider a GRB with photon energy 1 TeV and neutrinos with the same energy, = 1 TeV. The dispersion relation 2 = 2 2 + 2 4 gives the speed of the neutrinos as 2 , where the masses are estimated with the heaviest neutrino mass. The speed of neutrinos is given by = 0.17 × 10 −26 .…”