The X-ray spectra of optically selected Seyfert 2 galaxies: are there any Seyfert 2 galaxies with no absorption?

We present an X-ray spectral analysis of a sample of eight bona fide Seyfer t 2 galaxies, selected on the basis of their high [O III]lambda 5007 flux, from the Ho et al. spectroscopic sample of nearby galaxies. We find that, i n general, the X-ray spectra of our Seyfert 2 galaxies are complex, with so me of our objects having spectra different from the 'typical' spectrum of X -ray selected Seyfert 2 galaxies. Two (NGC 3147 and 4698) show no evidence for intrinsic absorption. We suggest that this is a result of the fact that when the torus suppresses the intrinsic medium and hard energy flux, under lying emission from the host galaxy, originating in circumnuclear starburst s, and scattering from warm absorbers contributes in these energy bands mor e significantly. Our ASCA data alone cannot discriminate whether low-absorp tion objects are Compton-thick active galactic nuclei (AGNs) with a strong scattered component or lack an obscuring torus. The most striking example o f our low absorption Seyfert 2 is NGC 4698. Its spectrum could be explained by either a dusty warm absorber or a lack of broad-line clouds so that its appearance as a Seyfert 2 is intrinsic and not a result of absorption.