2016MNRAS.460.4403R

In this paper, we attempt to find out the 'spectro-temporal' characteristics during the jet ejection, of several outbursting Galactic black hole sources based on RXTE-Proportional Counter Array (PCA)/High Energy X-ray Timing Experiment (HEXTE) data in the energy band of 2-100 keV. We present results of detailed analysis of these sources during the rising phase of their outburst, whenever simultaneous or near-simultaneous X-ray and radio observations are 'available'. We find that before the peak radio flare (transient jet) a few of the sources (in addition to those reported earlier) exhibit 'local' softening within the soft intermediate state itself. Except the duration, all the properties of the 'local' softening (Quasi Periodic Oscillation (QPO) not observed, reduction in total rms, soft spectra) are observed to be similar to the canonical soft state. We find similar 'local' softening for the recent outburst of V404 Cyg also based on SWIFT observations. Fast changes in the 'spectro-temporal' properties during the 'local' softening imply that it may not be occurring due to change in Keplerian accretion rate. We discuss these results in the framework of the magnetized two component advective flow model.