Accretion Disc Wind Variability in the States of the Microquasar GRS 1915+105

TL;DR

This study investigates how accretion disc winds in the microquasar GRS 1915+105 vary across different states, revealing the link between inner disc activity, wind ionization, and jet ejections through high-resolution spectral analysis.

Contribution

It provides new evidence connecting inner and outer disc dynamics and wind ionization states during different accretion states using high-resolution spectral data.

Findings

Radiation links inner and outer accretion discs on various time-scales.

Wind over-ionization correlates with increased X-ray flux during gamma state.

Inner disc changes and jet ejections influence wind quenching in beta state.

Abstract

Continuing our study of the role and evolution of accretion disc winds in the microquasar GRS 1915+105, we present high-resolution spectral variability analysis of the beta and gamma states with the Chandra High Energy Transmission Grating Spectrometer. By tracking changes in the absorption lines from the accretion disc wind, we find new evidence that radiation links the inner and outer accretion discs on a range of time-scales. As the central X-ray flux rises during the high-luminosity gamma state, we observe the progressive over-ionization of the wind. In the beta state, we argue that changes in the inner disc leading to the ejection of a transient 'baby jet' also quench the highly-ionized wind from the outer disc. Our analysis reveals how the state, structure, and X-ray luminosity of the inner accretion disc all conspire to drive the formation and variability of highly-ionized accretion disc winds.