Suzaku observations of hard X-ray selected Seyfert 2 galaxies

We present Suzaku observations of five hard X-ray-selected nearby Seyfert 2 galaxies. All the sources were clearly detected with the PIN Hard X-ray Detector up to several tens of keV, allowing for a fairly good characterization of the broadband X-ray continuum. We find that a unique model, even including multiple components, fails to represent the spectra of all the sources. Heavy obscuration manifests itself in different ways. For two sources, there is evidence for a reflection-dominated continuum; among the other three, one is “mildly” Compton thick (CT; NH ∼ 1024 cm−2), while the remaining two are heavily obscured (NH ≃ 1023.5 cm−2) but Compton thin. Strong, narrow, iron Kα lines (EW ∼ 1–2 keV) due to neutral or mildly ionized gas are detected in CT active galactic nuclei (AGNs). In all of them, the Kα line is accompanied by the Kβ. The intensity and shape of the soft X-ray spectrum are different from object to object. Soft X-rays may originate from a nuclear component scattered off, or leaking through, the X-ray absorber plus thermal X-rays from the host galaxy. Emission from circumnuclear gas photoionized by the active nucleus, parameterized with a power law plus individual narrow Gaussian lines, also provides an acceptable description of the soft X-ray spectra. The limited Suzaku XIS CCD energy resolution does not allow us to draw firm conclusions about the origin of the soft X-ray emission. We briefly discuss our findings in the light of the AGN unified model and the geometry of the obscuring gas.