The host-galaxy of the gamma-ray Narrow-line Seyfert 1 galaxy
  1H~0323+342
  We present optical and near infrared (NIR) imaging data of the radio-loud
Narrow-line Seyfert 1 galaxy 1H 0323+342, which shows intense and variable
gamma-ray activity discovered by the Fermi satellite with the Large Area
Telescope. NIR and optical images are used to investigate the structural
properties of the host galaxy of 1H 0323+342; this together with optical
spectroscopy allowed us to examine its black hole mass. Based on the 2D
multiwavelength surface brightness modeling, we find that, statistically, the
best model fit is a combination of a nuclear component and a S\'ersic profile
(n~2.8). However, the presence of a disc component (with a small bulge n~1.2)
remains also a possibility and cannot be ruled out with the present data.
Although at first glance a spiral-arm like structure is revealed in our images,
a 2D Fourier analysis of the imagery suggests that such structure corresponds
to an asymmetric ring, likely associated to a recent violent dynamical
interaction. We discuss our results on the context of relativistic jets
production and galaxy evolution.
