On the CQE phase signature of high resolution spectro-interferometry of Be stars

In this contribution we analyse and quantify a feature that is detected at the differential phases of high-resolution 
spectro-interferometry of Be stars.
The origin of this feature (dubbed CQE PS, Central Quasi Emission Phase Signature) lies on the differential absorption of 
photospheric radiation by the circumstellar disk, which is spectroscopically detected as a CQE line profile in shell stars. This 
phenomenon has great diagnostic potential for Be star disks, revealing the properties of these disks on the scale of a few 
stellar radii. In particular, we demonstrate that the CQE PS can be used to determine the density scale, the density profile, 
the disk size and, in some circumstances, the rotation rate of the star.