Prompt TeV neutrinos from the dissipative photospheres of gamma-ray bursts

Abstract

Recently it was suggested that a photospheric component that results from internal dissipation occurring in the optically thick inner parts of relativistic outflows may be present in the prompt γ/X-ray emission of gamma-ray bursts or X-ray flashes. We explore high-energy neutrino emission in this dissipative photosphere model, assuming that the composition of the outflow is baryon dominated. We find that neutrino emission from a proton-proton collision process forms an interesting signature in the neutrino spectra. Under favorable conditions for the shock dissipation site, these low-energy neutrinos could be detected by km3 detectors, such as Icecube. Higher-energy (≳10 TeV) neutrino emission from proton-proton collision and photopion production processes could be significantly suppressed for dissipation at relatively small radii due to efficient Bethe-Heitler cooling of protons and/or radiative cooling of the secondary mesons in the photosphere radiation. As the dissipation shocks continue further out, high-energy neutrinos from the photopion production process become dominant. © 2009. The American Astronomical Society. All rights reserved..