Discovery of Jet-Induced Soft Lags of XTE J1550-564 during Its 1998 Outburst

TL;DR

This study identifies jet-induced soft X-ray lags in XTE J1550-564 during its 1998 outburst, revealing a correlation with radio flux and suggesting jet activity influences X-ray timing properties.

Contribution

It demonstrates a direct anti-correlation between X-ray time lag and radio flux, proposing jet activity as a cause for soft lags, a novel insight into disk-jet interactions.

Findings

Anti-correlation between X-ray lag and radio flux.

Soft lags linked to changes in accretion disk structure.

Jets contribute significantly to X-ray timing properties.

Abstract

X-ray time lags are complicated in nature. The exact reasons for complex lag spectra are yet to be known. However, the hard lags, in general, are believed to be originated due to the inverse Comptonization process. But, the origin of soft lags remained mischievous. Recent studies on "Disk-Jet Connections" revealed that the jets are also contributing to the X-ray spectral and timing properties in a magnitude which was more than what was predicted earlier. In this article, we first show an exact anti-correlation between X-ray time lag and radio flux for XTE J1550-546 during its 1998 outburst. We propose that the soft lags might be generated due to the change in the accretion disk structure along the line of sight during higher jet activity.