Emrah Kalemci (Sabanci University, Turkey)

X-ray timing of black hole transients as the compact jet turns on

Compact, steady jets are observed in near infrared and radio bands in the hard state of Galactic black hole
transients as their luminosity decreases and the source moves towards a quiescent state. Our group conduct
multiwavelength observations of these sources during the outburst decay to understand the process of jet
formation, and the contribution of jets to X-ray spectral and temporal properties. Recent radio observations
indicate that the jets turn off completely in the soft state, therefore these investigations do probe the
formation process and the associated timescales.
In this presentation we will show the results of a systematic study involving the timescales of changes in Xray
spectral and temporal properties of black hole transients as the jets turns on. The study includes the
study of lag timescales between jet formation and changes in X-ray properties, and the evolution of QPO
properties along with the evolution of jet flux. The study will also show that we still lack crucial data that could
link X-ray timing properties to jet, and how LOFT would contribute.