Ultrahigh Energy Cosmic Rays and Black Hole Mergers

TL;DR

This paper explores the possibility that black hole mergers, especially those with spin and magnetic fields, could be a source of ultrahigh energy cosmic rays, linking gravitational wave events to cosmic ray origins.

Contribution

It proposes a novel hypothesis that black hole mergers can accelerate cosmic rays to ultrahigh energies, given certain astrophysical conditions.

Findings

Black hole mergers can potentially accelerate cosmic rays to ultrahigh energies.

Modest efficiency (< 0.01) per event is sufficient for this acceleration.

Relic magnetic fields and debris are crucial for the acceleration process.

Abstract

The recent detection of the gravitational wave source GW150914 by the LIGO collaboration motivates a speculative source for the origin of ultrahigh energy cosmic rays as a possible byproduct of the immense energies achieved in black hole mergers, provided that the black holes have spin as seems inevitable and there are relic magnetic fields and disk debris remaining from the formation of the black holes or from their accretion history. We argue that given the modest efficiency $< 0.01$ required per event per unit of gravitational wave energy release, merging black holes potentially provide an environment for accelerating cosmic rays to ultrahigh energies.