A Comparison between the Narrow-Line Regions of Seyfert 1 and Seyfert 2 Galaxies

Abstract

We present high-resolution narrow-band [O III] images of Seyfert 1 and Seyfert 2 galaxies, obtained in the Hubble Space Telescope Data Archive. The continuum-subtracted [O III] images were used to measure the narrow- line region (NLR) sizes and compare them with the predictions from the Unified Scheme. This paper shows that the Seyfert 1 NLR sizes are much smaller than the NLR sizes of the Seyfert 2's if they were observed pole- on. We propose that the Unified Scheme is not wrong but rather that the Seyfert 1's may have their torus axes aligned close to the galaxy plane axis.