Complete Multiwavelength Evolution of Galactic Black Hole Transients During Outburst Decay II: Compact Jets and X-ray Variability Properties

TL;DR

This study explores how compact jet emissions and X-ray variability in black hole transients evolve during outburst decay, revealing correlations with radio/infrared observations and supporting models of jet and accretion physics.

Contribution

It provides a comprehensive analysis of the relationship between jet activity, X-ray variability, and spectral components across multiple sources during outburst decay.

Findings

Stronger broadband X-ray variability in standard sources when jets turn on.

QPO amplitudes increase early in decay but diminish after jet activation.

Supports the internal shock and magnetically dominated accretion flow models.

Abstract

We investigated the relation between compact jet emission and X-ray variability properties of all black hole transients with multiwavelength coverage during their outburst decays. We studied the evolution of all power spectral components (including low frequency quasi-periodic oscillations), and related this evolution to changes in jet properties tracked by radio and infrared observations. We grouped sources according to their tracks in radio/X-ray luminosity relation, and show that the standards show stronger broadband X-ray variability than outliers at a given X-ray luminosity when the compact jet turned on. This trend is consistent with the internal shock model and can be important for the understanding of the presence of tracks in the radio/X-ray luminosity relation. We also observed that the total and the QPO rms amplitudes increase together during the earlier part of the outburst decay, but after the compact jet turns either the QPO disappears or its rms amplitude decreases significantly while the total rms amplitudes remain high. We discuss these results with a scenario including a variable corona and a non-variable disk with a mechanism for the QPO separate from the mechanism that create broad components. Finally, we evaluated the timing predictions of the magnetically dominated accretion flow model which can explain the presence of tracks in the radio/X-ray luminosity relation.