Disc atmospheres and winds in X-ray binaries

TL;DR

This paper reviews the mechanisms behind disc atmospheres and winds in low mass X-ray binaries, highlighting how thermal and radiative pressures explain observations and their role in iron emission lines.

Contribution

It provides a comprehensive comparison of wind launching models with observations, emphasizing the combined effects of thermal and radiative pressures.

Findings

Thermal and radiative pressures can explain observed winds.

Winds and atmospheres may significantly contribute to iron emission lines.

Models align with observations across neutron star and black hole binaries.

Abstract

We review the current status of studies of disc atmospheres and winds in low mass X-ray binaries. We discuss the possible wind launching mechanisms and compare the predictions of the models with the existent observations. We conclude that a combination of thermal and radiative pressure (the latter being relevant at high luminosities) can explain the current observations of atmospheres and winds in both neutron star and black hole binaries. Moreover, these winds and atmospheres could contribute significantly to the broad iron emission line observed in these systems.