  Detailed line profile variability studies of the narrow line Seyfert 1 galaxy
Mrk110 are presented. We obtained the spectra in a variability campaign carried
out with the 9.2m Hobby-Eberly Telescope at McDonald Observatory. The
integrated Balmer and Helium (HeI,II) emission lines are delayed by 3 to 33
light days to the optical continuum variations respectively. The outer wings of
the line profiles respond much faster to continuum variations than the central
regions. The comparison of the observed profile variations with model
calculations of different velocity fields indicates an accretion disk structure
of the broad line emitting region in Mrk110. Comparing the velocity-delay maps
of the different emission lines among each other a clear radial stratification
in the BLR can be recognized. Furthermore, delays of the red line wings are
slightly shorter than those of the blue wings. This indicates an accretion disk
wind in the BLR of Mrk110. We determine a central black hole mass of M =
$1.8\cdot10^{7} M_{\odot}$. Because of the poorly known inclination angle of
the accretion disk this is a lower limit only.
