Episodic gamma-ray and neutrino emission from the low mass X-ray binary GRO J0422+32

TL;DR

This paper models the gamma-ray and neutrino emissions from the low-mass X-ray binary GRO J0422+32 during an outburst, predicting observable signals and exploring non-thermal processes in the system.

Contribution

It introduces a corona model for GRO J0422+32's emission, solving particle interactions self-consistently, and provides testable predictions for high-energy observations.

Findings

Persistent power-law spectrum up to 1 MeV observed.

Model fits electromagnetic emission during flaring phase.

Predicts neutrino production detectable by future instruments.

Abstract

GRO J0422+32 is a member of the class of low-mass X-ray binary (LMXB) sources, discovered during an outburst in 1992. Along the entire episode ($\sim 230$ days) a persistent power-law spectral component extending up to $\sim 1$ MeV was observed. These results suggest that non-thermal processes must be at work in the system. We apply a corona model to describe the spectrum of GRO J0422+32 during the flaring phase. We study relativistic particle interactions solving the transport equations for all type of particles self-consistently. We fit the electromagnetic emission during the plateau phase of the event and estimate the emission during an energetic episode, as well as the neutrino production. Our work leads to predictions that can be tested by the new generation of very high energy gamma-ray instruments.