A unified paradigm for the spectral and temporal evolution of Black Hole X-ray Binaries

Abstract

We present a unified picture to explain the spectral states of BH binaries based on the two-flow model. In our view, the central regions have a multi-flow configuration consisting in (1) an outer standard accretion disc (SAD) down to a transition radius $r_{tr}$, (2) an inner magnetized jet emitting disc (JED) below $r_{tr}$ driving (3) a self-collimated non relativistic MHD jet surrounding, when conditions for pair creation are met, (4) a ultra relativistic pair beam. Large values of $r_{tr}$ correspond to Hard states while small values correspond to Soft states. In between these extremes, in the high intermediate state, $r_{tr}$ can reach values that switch on a pair cascade process giving birth to ultra-relativistic pair blobs that explain the superluminal events. In this model the accretion rate but also the disc magnetization $\mu$ play important roles, the latter being necessarily in the range 0.1-1 for the MHD jet to exist. Then, with simple assumptions on $\mu$, we propose an explanation for the hysteresis behavior observed in microquasars during their outburst. We also discuss the nature, in our framework, of the X-ray corona and the origin of the X-ray variability in the hard state. Preliminary results are discussed.

arXiv comment14 pages, 7 Figures. Contributed talk at the VIth Microquasar Workshop: "Microquasars and beyond" (Como, Italy), eds: T. Belloni et al. September 2006

References in corpus (13)

• Advection-Dominated Accretion and the Spectral States of Black Hole X-Ray Binaries: Application to Nova Muscae 1991
• The evolution of the timing properties of the black-hole transient GX 339-4 during its 2002/2003 outburst
• Radio / X-ray correlation in the low/hard state of GX 339--4
• On the Origin of Radio Emission in the X-ray States of XTE J1650-500 during the 2001-2002 Outburst
• Variability in black hole accretion discs
• INTEGRAL/RossiXTE high-energy observation of a state transition of GX 339-4
• Predicted rotation signatures in MHD disc winds and comparison to DG Tau observations
• A transient variable 6 Hz QPO from GX 339-4
• Magnetically-driven jets from Keplerian accretion discs
• Acceleration and collimation of relativistic plasmas ejected by fast rotators
• A Relativistic Fe K-alpha Emission Line in the Intermediate Luminosity BeppoSAX Spectrum of the Galactic Microquasar V4641 Sgr
• Rapid variability of the arcsec-scale X-ray jets of SS 433
• Magnetized accretion-ejection structures IV. Magnetically-driven jets from resistive, viscous, Keplerian discs