Accretion-Ejection Instability, LFQPO and lag structure of microquasars

摘要

The Accretion-Ejection Instability (AEI) has been proposed to explain the low frequency Quasi-Periodic Oscillation (QPO) observed in low-mass X-Ray Binaries. Its frequency, typically a fraction of the Keplerian frequency at the disk inner radius, is in the right range indicated by observations. I will briefly review the basic of the instability. In a second part I will focus on a simple model to explain the complex lag structure between the hard and soft X-ray observed in microquasars such as GRS 1915+105.