Suzaku Observations of Iron Lines and Reflection in AGN

Abstract

Initial results on the iron K-shell line and reflection component in several AGN observed as part of the Suzaku Guaranteed time program are reviewed. This paper discusses a small sample of Compton-thin Seyferts observed to date with Suzaku; namely MCG -5-23-16, MCG -6-30-15, NGC 4051, NGC 3516, NGC 2110, 3C 120 and NGC 2992. The broad iron K$α$ emission line appears to be present in all but one of these Seyfert galaxies, while the narrow core of the line from distant matter is ubiquitous in all the observations. The iron line in MCG -6-30-15 shows the most extreme relativistic blurring of all the objects, the red-wing of the line requires the inner accretion disk to extend inwards to within 2.2Rg of the black hole, in agreement with the XMM-Newton observations. Strong excess emission in the Hard X-ray Detector (HXD) above 10 keV is observed in many of these Seyfert galaxies, consistent with the presence of a reflection component from reprocessing in Compton-thick matter (e.g. the accretion disk). Only one Seyfert galaxy (NGC 2110) shows neither a broad iron line nor a reflection component. The spectral variability of MCG -6-30-15, MCG -5-23-16 and NGC 4051 is also discussed. In all 3 cases, the spectra appear harder when the source is fainter, while there is little variability of the iron line or reflection component with source flux. This agrees with a simple two component spectral model, whereby the variable emission is the primary power-law, while the iron line and reflection component remain relatively constant.