Multiwavelength Study of Seyfert Galaxies

Seyfert galaxies are a subclass of active galaxies and are categorized as nearby, low luminosity, radio-quiet Active Galactic Nuclei (AGN) hosted in spiral or lenticular galaxies. Seyfert galaxies are classified mainly into two subclasses named as `type 1' and `type 2' based on the presence and absence of broad permitted emission lines in their optical spectra, respectively. Seyfert unification scheme hypothesizes that Seyfert type 1s and type 2s belong to the same parent population and appear different solely due to the differing orientations of the obscuring material having a torus-like geometry around the AGN. The primary objective of this work is to examine the validity and limitations of the orientation and obscuration based Seyfert unification scheme using multiwavelength (mainly X-ray and radio) observations. It has been emphasized that the key issue in testing the Seyfert unification scheme is acquiring a well defined Seyfert sample. The statistical comparisons of X-ray, radio and IR properties of the two Seyfert subtypes have been discussed in the framework of the unification scheme.