Neutrino lighthouse powered by Sagittarius A* disk dynamo

TL;DR

This paper proposes that high-energy neutrinos detected by IceCube from the Galactic center could originate from proton collisions accelerated by the Sagittarius A* disk dynamo, with potential observational signatures in X-ray and EeV neutrinos.

Contribution

It introduces a novel model linking Sagittarius A*'s disk dynamo to high-energy neutrino production and suggests observational tests via X-ray and ultra-high-energy neutrino detection.

Findings

Sagittarius A* can accelerate protons to multi-PeV energies.

PeV neutrino progenitors emit keV curvature photons detectable by Chandra.

EeV neutrinos from black hole mergers could confirm particle acceleration mechanisms.

Abstract

We show that the subset of high energy neutrino events detected by IceCube which correlate with the Galactic center (within uncertainties of their reconstructed arrival directions) could originate in the collisions of protons accelerated by the Sagittarius (Sgr) A* disk dynamo. Under very reasonable assumptions on source parameters we demonstrate that the supermassive black hole at the center of the Galaxy could launch protons and nuclei with multi PeV energies. Acceleration of these particles in a period of seconds up to Lorentz factors of \sim 10^7 is possible by means of the Blandford-Znajek mechanism, which wires the spinning magnetosphere of Sgr A* as a Faraday unipolar inductor. During the acceleration process the \sim PeV progenitors of \sim 50 TeV neutrinos radiate curvature photons in the keV energy range. We show that IceCube neutrino astronomy with photon tagging on the Chandra X-ray Observatory could provide a valuable probe for the Blandford-Znajek acceleration mechanism. We also argue that EeV neutrinos, which may be produced in a similar fashion during the merging of binary black holes, could become the smoking gun for particle acceleration in a one-shot boost.