'Spectro-temporal' variabilities and possible physical mechanism for Jet ejections

Abstract

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-PCA/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 (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 implies 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.