Ultrahigh-energy neutrinos as a probe of espresso-shear acceleration in jets of Centaurus A

TL;DR

This paper models the production of ultrahigh-energy neutrinos in the jet of Centaurus A to assess detectability and constrain its role in cosmic-ray origins, using magnetohydrodynamic simulations and neutrino flux predictions.

Contribution

It presents a detailed bottom-up simulation of proton acceleration in Cen A's jet and predicts neutrino fluxes for current and future detectors.

Findings

Detection of neutrinos at 10^{17}-10^{18} eV from Cen A requires highly sensitive detectors.

Predicted neutrino fluxes are close to the sensitivity limits of planned neutrino observatories.

Successful detection could help constrain Cen A's contribution to ultrahigh-energy cosmic rays.

Abstract

It has been suggested that Centaurus A (Cen A) could make a contribution to the observed ultrahigh-energy cosmic-ray (UHECR) flux. We calculate the flux of astrophysical neutrinos produced by UHECRs accelerated in the jet of Cen A, a close-by jetted active galactic nucleus. We use a bottom-up approach, in which we follow the energization of protons and heavier elements in a magnetohydrodynamic simulation of a relativistic jet with proper parameters of Cen A, also accounting for attenuation losses based on the observed photon fields. We compare the expected neutrino flux with the sensitivity of current and planned neutrino detectors. We find that the detection of $\sim 10^{17}$-$10^{18}$ eV neutrinos from Cen A would require ultimate neutrino detectors that reach a point source sensitivity of $\sim {\rm a~few}\times10^{-13}~{\rm erg}~{\rm cm}^{-2}~{\rm s}^{-1}$. Successful detection, though challenging, would be useful in constraining the Cen A contribution to the UHECRs.