Neutrino and Cosmic-Ray Emission from Multiple Internal Shocks in Gamma-Ray Bursts

Bustamante, Mauricio; Murase, Kohta; Winter, Walter; Baerwald, Philipp

Preprint/Internal Report

PUBDB-2015-00416

Neutrino and Cosmic-Ray Emission from Multiple Internal Shocks in Gamma-Ray Bursts

Bustamante, M. (Corresponding Author)DESY* ; Baerwald, P. ; Murase, K. ; Winter, W.DESY*

2014

This record in other databases:

Report No.: arXiv:1409.2874

Abstract: In the classical theory of gamma-ray bursts, it is expected that particles are accelerated at mildly relativistic shocks generated by the collisions of material ejected from a central engine. We consider neutrino and cosmic-ray emission from multiple emission regions since these internal collisions must occur at very different radii, from below the photosphere all the way out to the circumburst medium, as a consequence of the efficient dissipation of kinetic energy. We demonstrate that the different messengers originate from different collision radii, which means that multimessenger observations open windows for revealing the evolving GRB outflows. We find that, even in the internal shock model, the neutrino production can be dominated by emission from around the photosphere, i.e., the radius where the ejecta become transparent to gamma-ray emission. Possible subphotospheric contributions enhance the detectability. We predict a minimal neutrino flux per flavor at the level of E^2 J ~ 10^{-11} GeV cm^{-2} sr^{-1} s^{-1} for the contribution from beyond the photosphere, with a spectral shape similar to the original theoretical prediction. However, in striking contrast to earlier approaches, this prediction turns out to hardly depend on model parameters such as the Lorentz boost or the baryonic loading. This implies that the hypothesis that ultra-high-energy cosmic rays originate from GRBs can be more robustly tested.

Note: OA

Contributing Institute(s):