High-energy neutrinos from Galactic superbubbles

TL;DR

This paper investigates how superbubbles in our galaxy can enhance cosmic ray interactions in their walls, leading to significant high-energy neutrino production near young cosmic ray sources like Vela.

Contribution

It introduces a model where superbubble walls increase cosmic ray density and interaction probability, explaining observed high-energy neutrinos from galactic sources.

Findings

Superbubble walls boost cosmic ray density and interactions.

Nearby superbubbles can produce a substantial fraction of observed neutrinos.

Cosmic rays from sources like Vela can generate neutrinos below a few hundred TeV.

Abstract

We study the propagation of cosmic rays generated by sources residing inside superbubbles. We show that the enhanced magnetic field in the bubble wall leads to an increase of the interior cosmic ray density. Because of the large matter density in the wall, the probability for cosmic ray interactions on gas peaks there. As a result, the walls of superbubbles located near young cosmic ray sources emit efficiently neutrinos. We apply this scenario to the Loop~I and Local Superbubble: These bubbles are sufficiently near such that cosmic rays from a young source as Vela interacting in the bubble wall can generate a substantial fraction of the observed astrophysical high-energy neutrino flux below $\sim$ few $\times 100$ TeV.