The flat X-ray spectrum of the LINER NGC 1052

Abstract

We report on ROSAT and ASCA observations of the LINER NGC 1052, which is the first one where broad optical lines in polarized light have been observed. The 2-10 keV spectrum is very flat, with a Γobserved ≃ 0.1. A model where a nuclear source is - partly or totally -obscured by a screen of matter with column density ∼1023 cm-2 is the most convincing explanation for the observed flatness. This agrees with the hypothesis that the LINERs are a population of low-luminosity AGN, to which the Seyfert unification scenario applies. The intrinsic spectral index is still rather flat (Γinstrinsic ≃ 1.0-1.4), as observed in a few type 2 Seyferts so far or predicted if the accretion occurs in an advection-dominated flow.