Line shifts and sub-pc super-massive binary black holes
  Here we discuss the possibility of super-massive binary black hole (SMBBH)
detection, using the shifts of the broad lines emitted from a binary system. We
perform a number of simulations of shapes and shifts of $H_{\beta}$ lines
emitted from SMBBHs, taking into account the emission from two different
regions located around both black holes, and kinematical effects which should
be present in a SMBBH. In the model we connect the parameters of the lines with
the mass of black holes and find that the peak shift depends, not only on
kinematical effects of system rotation and black hole mass ratio, but it is
also a function of the individual masses of the two black holes (BHs).
