Microquasars - Generalized Flood
Fender, Belloni and Gallo (2005) made an important step toward a unified model for the microquasar disk+jet states by producing the evolutionary track shown on the hardness-intensity diagram (shown on the figure 3) for a variety of black hole binaries. Indeed, objects that appear wildly different in their day-to-day behavior are on similar tracks in the hardness-intensity diagram. An extended version of the MFS has been proposed to explain the schema below.
The Hardness-Intensity Diagram of Fender, Belloni and Gallo surimposed with the extended version of the MFS showing the direction of the magnetic flux in the disk and the inner hole. this behavior. It is based on the stored magnetic flux as shown on the schema.
The Hardness-Intensity Diagram of Fender, Belloni and Gallo surimposed with the extended version of the MFS
showing
the direction of the magnetic flux in the disk and the inner hole.
If we assume the starting configuration (1 on the figure) where the magnetic flux stored around the black hole and the disk flux are parallel, the disk innner radius is large and accretion remains weak. Now let us assume a field reversal (dynamo in the disk or the companion) in the flux advected in the disk (2), we obtain a slow decrease of the stored flux by (3) and at the same time the inner radius of the disk decreases.
During all that time, the AEI is present in the disk, it is the low-hard state. At that point there are two possibilities: no field reversal occurs until all the stored flux is cancelled by the disk flux (4), we obtain a global reconfiguation of the magnetic field, which favor a ejection and the disk is back at its last stable orbit, or there is a field reversal before that and we obtain a failed-flare as seen sometimes.
Slowly the stored flux is rebuilt, parallel to the disk one (5), up to a strong stored flux (6) which is the same as configuration (1) but in the opposite direction.