Chris Done (Durham) - Accretion disks in strong gravity

I will review the spectral and timing properties of X-ray binaries, especially the behaviour seen
as the source makes a transition from the low/hard to high/soft state. The broad band spectral
evolution is well modeled by a truncated disc/hot inner flow geometry, where the truncation
radius moves progressively towards the last stable orbit during this transition. Here I show
that this same geometry can also quantatatively match the power spectral evolution, where
fluctuations propagating through the hot flow (stirred up by the MRI) make the broad band
continuum power spectra, and Lense-Thirring precession of the hot flow makes the prominent
low frequency QPO. I will discuss how these models can be critically tested using LOFT.