High-energy Neutrino Predictions for T Coronae Borealis: Probing Particle Acceleration in Novae

TL;DR

This paper analyzes the potential for detecting neutrinos from the upcoming T Coronae Borealis nova, comparing two particle acceleration mechanisms and their observable signatures across gamma-ray and neutrino observatories.

Contribution

It provides the first comparative analysis of hadronic secondary fluxes from T CrB and evaluates their detectability, highlighting the potential to distinguish acceleration mechanisms via neutrino timing.

Findings

Magnetic reconnection scenario predicts neutrino flux detectable by IceCube and KM3NeT.

External shock model predicts gamma-ray detection but negligible neutrino flux.

Neutrinos from magnetic reconnection arrive hours before gamma-ray signals, offering a way to probe acceleration physics.

Abstract

The MAGIC detection of near-TeV gamma rays from the 2021 RS Oph ($2.45$ kpc) outburst has established recurrent novae as TeV particle accelerators. However, the origin of this emission (hadronic vs leptonic) remains unclear due to the lack of coincident neutrinos detected by IceCube. The upcoming outburst of the much closer T Coronae Borealis (T CrB, $\sim0.887$ kpc) offers a unique opportunity to detect these rare nova neutrinos. Here we present the first comparative analysis of the hadronic secondary fluxes expected from the upcoming T CrB outburst and evaluate their detectability across major observatories, considering two proton-acceleration mechanisms: (i) an external shock (ES) at $\sim10^{13}$ cm, and (ii) magnetic reconnection (MR), near the white dwarf surface at $\sim10^{9}$ cm. While the benchmark ES model predicts a gamma-ray flux detectable by current facilities, its corresponding neutrino flux largely remains undetectable. In contrast, the MR scenario generates a robust neutrino flux within the reach of IceCube and KM3NeT. Importantly, as the MR-produced gamma-rays are absorbed, the escaping MR neutrinos will arrive hours before any ES-origin signals. This distinct temporal separation can create a powerful phenomenological signature to disentangle the nova acceleration physics.