Modulation of the disk Emission by the AEI | AEI is a Model for the LFQPO
Microquasars - LFQPO / AEI is a Model for the LFQPO
The AEI seems to be a promising candidate to explain low-frequency QPOs because it is able to account for the following observational characteristics :
- The LFQPO frequency is 
few 1/10 the Keplerian frequency at the inner edge of the disk. This is similar
to the rotation frequency of the one-armed spiral predicted in the the linear AEI theory and confirmed by
the non-linear simulations.
- The AEI can naturally predict not only the frequency of the LFQPO but can also reproduce, partially, the
X-ray flux modulation from the variation in disk properties at the location of the spiral wave.
- The AEI does not require external excitation but grows naturally when the 
(the ratio of thermal to
magnetic pressure).
- The AEI creates a large scale wave similar to Galactic spiral density waves. The non-linear simulations show
that the rotating pattern remains nearly steady, and thus is a able to account for persistent LFQPOs.
- The AEI transfers energy and angular momentum toward the corona by Alfven Waves, thus providing a supply of Poynting flux that may produce the compact jet, often observed in the low-hard state.
- Including general relativity through the existence of a last stable orbit and orbital velocity profile has allowed
us to show that the AEI can explain the observed turnover in the correlation between the color radius (=
inner disk radius, as determined by the spectral fits) and the LFQPO frequency. (Rodriguez et al 2002; Varniere et al 2002).