Search for high energy neutrinos from bright GRBs with ANTARES

S Celli,Antares Collaboration ,M Sanguineti,D Turpin

doi:10.1088/1742-6596/888/1/012100

Abstract

Gamma-ray bursts are thought to be cosmic-ray accelerators, thus neutrinos are expected from the decay of charged mesons, produced in pγ interactions. The search for high-energy neutrinos from astrophysical sources is one of the main goals of the ANTARES scientific project. The methods and the results of a search for neutrinos from the brightest GRBs observed between 2008 and 2013 are presented. Two scenarios of the fireball model have been investigated: the internal shock and the photospheric case. Since no events have been detected in time and space coincidence with any of these bursts, upper limits at 90% C.L. on the expected neutrino fluxes are derived, as well as constraints on some parameters used in the modeling of the neutrino yield, as the bulk Lorentz factor of the jet and the baryon loading fp.

Highlights

The existence of hadronic acceleration mechanisms in Gamma-Ray Bursts (GRBs) would be unambiguously proven by the identification of high-energy neutrinos in temporal and spatial coincidence with the prompt emission of the burst
The individual limits derived for these bright GRBs are consistent with the limits shown in previous ANTARES stacking searches, which refer to the Internal Shock (IS) model only
This search extends the ANTARES neutrino detection capability from GRBs into the low-energy regime; compared to what was shown in previous ANTARES searches for muon neutrinos in coincidence with 296 GRBs during four years of data (Adrián-Martínez et al 2013b), it confirms the sensitivity in the high-energy regime, i.e. above 100 TeV

Summary

Introduction

The existence of hadronic acceleration mechanisms in Gamma-Ray Bursts (GRBs) would be unambiguously proven by the identification of high-energy neutrinos in temporal and spatial coincidence with the prompt emission of the burst. In order to test different scenarios, including those in which GRBs are able to reproduce the magnitude of the UHECR flux observed on Earth (see for instance Waxman 1995, Vietri 1995, Wang et al 2008, Murase & Takami 2008 and Globus et al 2015), a multimessenger approach can be adopted For this purpose, the search for a possible neutrino counterpart can be crucial. The generally accepted picture is the Internal Shock (IS) scenario (Rees & Mészáros 1994, Kobayashi et al 1997 and Daigne & Mochkovitch 1998); the Photospheric (PH) scenario has been widely discussed in literature (Paczýnski 1986, Thompson 1994, Mészáros & Rees 2000 and Zhang & Kumar 2013) They both assume that internal shocks take place when a faster shell of plasma catches up with a slower one: such a mechanism dissipates a large fraction of the kinetic energy of the flow, provided that the internal engine is highly variable. The main channel goes through the production of the ∆+ and its subsequent decay into pions, according to: π0 −→ γ + γ p + γ −∆−→+

Methods

Results

Conclusion