The OH Megamaser galaxy IRAS11506-3851: an AGN and starformation
  revealed by multiwavelength observations
  We present Gemini Multi-Object Spectrograph (GMOS) Integral Field Unit (IFU),
Hubble Space Telescope (HST) and Very Large Array (VLA) observations of the OH
Megamaser (OHM) galaxy IRAS 11506-3851. The HST images reveal an isolated
spiral galaxy and the combination with the GMOS-IFU flux distributions and VLA
data allow us to identify a partial ring of star-forming regions surrounding
the nucleus with a radius of ~ 500 pc. While this ring shows starburst
excitation and low velocity dispersion, the region internal to the ring shows
higher excitation and velocity dispersion values, with values increasing
towards its borders at ~ 240 pc from the nucleus, resembling a projected
bubble. The enhanced excitation and velocity dispersion of this bubble
surrounds a 8.5 GHz radio emission structure, supporting its origin in a faint
AGN that is mostly shocking the surrounding gas via a plasma ejection seen in
radio at the present stage. This is the fourth of the 5 OHM galaxies we have
studied so far (from our sample of 15 OHM) for which GMOS-IFU data indicate the
presence of a previously unknown faint AGN at the nucleus, consistent with the
hypothesis that OHM galaxies harbor recently triggered AGN.
