Host galaxies of double-peaked [OIII] emitting AGN: binary AGN or
  mergers?
  Mergers are suspected to be reliable triggers of both starformation and AGN
activity. However, the exact timing of this process remains poorly understood.
Here, we present deep imaging and long slit spectroscopy data of a sample of
four double-peaked [OIII] emitting AGN. These sources are often believed to
host binary AGN, or at least be currently undergoing major mergers. The sample
presented here either have previous IFU and high resolution imaging data that
show double-nuclei in the IR as well as kinematicly and spatially distinct line
emitting regions. Two sources have detections of double point sources in either
the X-ray or radio. The sources studied are therefore likely binary AGN. The
AGN in this sample are luminous, radio-quiet and at low redshift. The $u/r/z$
imaging data show host galaxies in a wide range of merger stages, with the
majority (3/4) showing tidal tails or complex kinematics and morphologies
clearly indicating a recent merger. One source however -hosting a double X-ray
source- shows quiescent morphologies with no clear signs of interaction from
imaging data. The spectroscopy in this case reveals a gas disk counter-rotating
with respect to the stellar component. Spectroscopy of the other sources reveal
disturbed kinematics further confirming their status as ongoing mergers. Our
data show that AGN triggering in mergers may happen over a wide time span and
that sinking of black holes to the center of a merged system might take
considerable time in some cases. A detailed analysis will be published in an
upcoming paper. Further studies of AGN in merging galaxies will show how the
hosts of those AGN differ from normal mergers without AGN activity.
