Testing the neutrino annihilation model for launching GRB jets

Abstract

The mechanism behind the launching of gamma-ray-burst (GRB) jets remains debated resulting in large uncertainty over the jet composition. Both magnetohydrodynamical and neutrino annihilation models have been proposed for the energy extraction in a black hole/accretion-disc central engine. In particular, for the extreme accretion rates $\dot{M}\sim 0.1-1$~ M${}_{\odot }$s${}^{-1}$ expected for bursts of duration $T\lesssim 100$~s, the disc can be an efficient neutrino emitter. Neutrino-antineutrino annihilation results in an energy deposition rate at the jet that can, in principle, account for the burst's energetics. Recent discoveries of X-ray flares hours after the burst and of ultra-long GRBs suggest that GRB activity can last for $\sim 10^4$~s or longer. These long-lived events have fluence similar to that of classical GRBs. In view of these findings, we re-evaluate the neutrino annihilation model. We derive the maximum possible energy of a neutrino-powered jet as a function of the burst duration and show that the available energy drops fast for longer bursts. For a standard choice of the parameters, the model falls short by three to four orders of magnitude in explaining the observed energetics of events that last longer than $\sim 10^3$~s.

5 pages, 1 figure

References in corpus (5)

• Neutrino-Cooled Accretion Disks around Spinning Black Hole
• The ultra-long Gamma-Ray Burst 111209A: the collapse of a blue supergiant?
• The First Survey of X-ray Flares from Gamma Ray Bursts Observed by Swift: Spectral Properties and Energetics
• Neutrino pair annihilation near accreting, stellar-mass black holes
• Flares in GRB afterglows from delayed magnetic dissipation

Cited by in corpus (4)

• Constraints on millisecond magnetars as the engines of prompt emission in gamma-ray bursts
• Can black-hole neutrino-cooled disks power short gamma-ray bursts?
• Spontaneous Lorentz symmetry breaking effects on GRBs jets arising from neutrino pair annihilation process near a black hole
• Deciphering the properties of the central engine in GRB collapsars