Suzaku observations of active galactic nuclei detected in the Swift/BAT survey

We present the first results of Suzaku follow-up of new AGNs detected in the Swift/BAT survey. The Suzaku spectra of Swift J0601.9-8636 and Swift J0138.6-4001 reveal a heavily absorbed power law component with a column density of NH≅1023.5-24cm-2 that dominates above 10 keV, and an intense reflection component with a solid angle > approx 2π from a cold, optically thick medium. We find that these AGNs have an extremely small fraction of scattered light from the nucleus (> approx 0.5%) with respect to the intrinsic power law component. This indicates that they are buried in a very geometrically-thick torus with a small opening angle and/or have unusually small amount of gas responsible for scattering. Our results imply that there must be a significant number of yet unrecognized, very Compton thick AGNs in the local universe, which are difficult to detect even in the currently most sensitive optical or hard X-ray surveys. (author)