A Radio Polarimetric Study to Disentangle AGN Activity and
  Star-Formation in Seyfert Galaxies
  To understand the origin of radio emission in radio-quiet AGN and
differentiate between the contributions from star formation, AGN accretion, and
jets, we have observed a nearby sample of Seyfert galaxies along with a
comparison sample of starburst galaxies using the EVLA in full-polarization
mode in the B-array configuration. The radio morphologies of the Seyfert
galaxies show lobe/bubble-like features or prominent cores in radio emission
whereas the starburst galaxies show radio emission spatially coincident with
the star-forming regions seen in optical images. There is tentative evidence
that Seyferts tend to show more polarized structures than starburst galaxies at
the resolution of our observations. We find that unlike a sample of Seyfert
galaxies hosting kilo-parsec scale radio (KSR) emission, starburst galaxies
with superwinds do not show radio-excess compared to the radio-FIR correlation.
This suggests that shock acceleration is not adequate to explain the excess
radio emission seen in Seyferts and hence most likely have a jet-related
origin. We also find that the [O III] luminosity of the Seyferts is correlated
with the off-nuclear radio emission from the lobes, whereas it is not well
correlated with the total emission which also includes the core. This suggests
strong jet-medium interaction, which in turn limits the jet/lobe extents in
Seyferts. We find that the power contribution of AGN jet, AGN accretion, and
star formation is more or less comparable in our sample of Seyfert galaxies. We
also find indications of episodic AGN activity in many of our Seyfert galaxies.
