Compton-Thick X-ray Absorption in the Seyfert Galaxies Tololo 0109-383 and ESO 138-G1

Abstract

We present analyses of the ASCA X-ray spectra of two Seyfert galaxies, Tololo 0109-383 and ESO 138-G1. In both cases, spectral fitting reveals two statistically acceptable continuum models: Compton reflection and partial covering. Both spectra have strong iron K-alpha lines, with equivalent widths greater than 1.5 keV. These large equivalent widths are suggestive of heavier obscuration than that directly indicated by the partial-covering models (approximately 2 x 10^23 cm^-2), with the actual column densities being `Compton-thick' (i.e. N_H > 1.5 x 10^24 cm^-2). We use the hard X-ray/[O III] flux correlation for Seyferts and data from the literature to provide additional support for this hypothesis. Since Tololo 0109-383 is known to have optical type 1 characteristics such as broad Balmer line components and Fe II emission, this result marks it as a notable object.