The Be X-ray Binary Outburst Zoo

TL;DR

This paper systematically analyzes the diverse outburst behaviors of Be X-ray binaries, revealing complexities beyond traditional classifications and comparing observational data with theoretical models.

Contribution

It provides a comprehensive study of Be X-ray binary outbursts, highlighting their varied properties and challenging the simple normal/giant outburst scheme.

Findings

Outbursts exhibit pre-flares and peak shifts.

Multi-peaked outbursts are common.

Outburst properties correlate with system parameters.

Abstract

Be X-ray binaries are among the best known transient high-energy sources. Their outbursts are commonly classified into a simple scheme of 'normal' and 'giant' outbursts, but a closer look shows that actual outbursts do not always follow this simple scheme. Recent data show a variety of properties, like pre-flares, shifts of the outburst peaks with respect to the periastron, multi-peaked outbursts etc. We present results from a systematic study of a large number of outbursts monitored by various space missions, comparing outburst properties and their relation to system parameters and current theoretical understanding.