Time-dependent search for neutrino emission from X-ray binaries with the ANTARES telescope

Abstract

ANTARES is currently the largest neutrino telescope operating in the NorthernHemisphere, aiming at the detection of high-energy neutrinos from astrophysical sources. Neutrino telescopes constantly monitor at least one complete hemisphere of the sky, and are thus well-suited to detect neutrinos produced in transient astrophysical sources. A timedependent search has been applied to a list of 33 X-ray binaries undergoing high flaring activities in satellite data (RXTE/ASM, MAXI and Swift/BAT) and during hardness transition states in the 2008-2012 period. The background originating from interactions of charged cosmic rays in the Earth's atmosphere is drastically reduced by requiring a directional and temporal coincidence with astrophysical phenomena. The results of this search are presented together with comparisons between the neutrino flux upper limits and the neutrino flux predictions from astrophysical models. The neutrino flux upper limits resulting from this search limit the jet parameter space for some astrophysical models.

Time-dependent search for neutrino emission from Mrk 421 and Mrk 501 observed by the HAWC gamma-ray observatory

“…Additional searches in IceCube [10] show no correlated neutrinos. Similar time-dependent analyses have been performed in the past using ANTARES data, in particular for flaring blazars [11].…”

“…Adapted from [7] 4. Time-dependent search method A time-dependent search for neutrino candidades in coincidence with γ-rays from astrophysical sources is performed using an unbinned likelihood-ratio maximization method [11]. This is done via the test statistics, λ , defined as the ratio of the probability for the hypothesis of the background and signal (H sig+bkg ), called H 1 , over the probability of only background (H bkg ), called H 0 : 1) where N S (unknown) and N (known) are expected number of signal events and total number of events in the considered data sample, x i are observed event properties (δ i , RA i , dE/dX i , and t i ).…”

Time-dependent search of neutrino emission from X-ray and gamma-ray binaries with the ANTARES telescope

“…• Swift/BAT Hard X-ray Transient Monitor 1 : any high-mass XRB (HMXR) and low-mass XRB (LMXB) with significant time variabilities are initially selected. Their daily LCs are denoised with a maximum likelihood block [16] procedure and their flare significance characterised as done in previous analyses [12,17]. Sources with more than one flare above a 5 standard deviation significance are selected for the analysis.…”

“…In this contribution is presented a time-dependent analysis realised on the ANTARES [7,8] neutrino telescope data testing the above hypothesis. This analysis method reduces in a factor of 2-3 the signal required for a discovery with respect to a time integrated search [9,10] under the assumption of correlation of the neutrino signal with high-energy electromagnetic emission, as is carried out in previous similar analyses [11,12]. The hadronic hypothesis is tested by looking for a correlation between the neutrino emission and the observed X-ray and gamma-ray flares of the brightest variable XRBs and γRBs (see Sec.…”

Search for time correlations between ANTARES neutrino candidates and IceCube/High-Energy Starting Events

“…When dealing with transient emissions, the background of atmospheric neutrinos can be significantly reduced using a time-dependent approach that consists in searching for astrophysical neutrinos in smaller time windows around source flares (see e.g. [3]).…”