The Nature of Seyfert 2 Galaxies with Obscured Broad-Line Regions. I. Observations

We present high signal-to-noise ratio spectropolarimetric observations of 10 Seyfert 2 galaxies known to harbor obscured broad-line regions. Most of the data, covering the spectral range λλ3200-7400 at moderate resolution, were obtained with the Kast double spectrograph in combination with the CCD polarimeter on the Shane 3 m telescope at Lick Observatory. Optical polarimetric imaging was also obtained with the same telescope for one object (Mrk 463), and narrowband imaging observations were made for four galaxies using the Nickel 1 m telescope. We describe methods of data reduction and those used to correct the polarimetry data for contamination from Galactic interstellar polarization as well as dilution from unpolarized starlight in the Seyfert host galaxies. From a comparison of various spectral properties, we found that the hidden Seyfert 1 galaxies do not appear to differ significantly from the normal Seyfert 1 galaxies, although the apparent lack of Fe II emission in the polarized flux spectra of most of them is intriguing.