High energy neutrino early afterglows from gamma-ray bursts revisited

Abstract

The high energy neutrino emission from gamma-ray bursts (GRBs) has been expected in various scenarios. In this paper, we study the neutrino emission from early afterglows of GRBs, especially under the reverse-forward shock model and late prompt emission model. In the former model, the early afterglow emission occurs due to dissipation made by an external shock with the circumburst medium (CBM). In the latter model, internal dissipation such as internal shocks produces the shallow decay emission in early afterglows. We also discuss implications of recent Swift observations for neutrino signals in detail. Future neutrino detectors such as IceCube may detect neutrino signals from early afterglows, especially under the late prompt emission model, while the detection would be difficult under the reverse-forward shock model. Contribution to the neutrino background from the early afterglow emission may be at most comparable to that from the prompt emission unless the outflow making the early afterglow emission loads more nonthermal protons, and it may be important in the very high energies. Neutrino-detections are inviting because they could provide us with not only information on baryon acceleration but also one of the clues to the model of early afterglows. Finally, we compare various predictions for the neutrino background from GRBs, which are testable by future neutrino-observations.Comment: 18 pages, 12 figures, accepted for publication in PR

Ultrahigh-energy cosmic ray production by turbulence in gamma-ray burst jets and cosmogenic neutrinos

“…However, the Rayleigh-Taylor fingers arising from the instability can disrupt the smooth laminar shock structure needed for the first-order Fermi acceleration, and similar effects may also be associated with the RichtmyerMeshkov instability. The photon emission from the forward shock afterglow does not provide a large cooling effect on UHECRs [96]. Also, the X-ray flares [see e.g.…”

High Energy Cosmic Ray and Neutrino Astronomy

“…We discuss below some examples of ∼ 1 TeV neutrino emission predictions, that depend on the properties of the GRB progenitor. For a discussion of ∼ 10 18 eV neutrino emission during the afterglow phase see [40,74,91,102] and the reviews [70,71,95].…”

Prompt high-energy neutrinos from gamma-ray bursts in photospheric and synchrotron self-Compton scenarios

“…is the proton loss time scale (in the comoving frame), where t BH , t pγ , t pp , t syn , t IC , t ad , and t esc are cooling times of the Bethe-Heitler process, photomeson production, pp reaction, synchrotron emission, inverse Compton emission, adiabatic expansion, and the escape time in the Bohm diffusion approximation [5,6]. Following Refs.…”

“…Our method of calculation based on Geant4 is basically the same as in Refs. [3,6], but improved qualitatively and quantitatively by including the pp reaction and all the relevant processes of protons, mesons and muons [16,17]. As for GRB neutrinos, cooling of mesons and muons is remarkably important, which makes neutrino spectra complicated and affects estimate of event rates [2,5,17].…”

“…[6] and references therein). However, despite recent progresses in the Swift era, the mechanism of prompt emission has not been well understood [7].…”