We present measurements of the Fe-Kα line for nine Seyfert I galaxies using Chandra High Energy Transmission Grating Spectrometer (HETGS) data. The centroid energies are narrowly dispersed (6.403 ± 0.062 keV) and indicate an origin of the line cores in cold matter. If all the lines in this sample were the peaks of a relativistically broadened disk line, it would require unrealistically fine tuning. However, at least three of the nine AGN clearly show a complex Fe-Kα line with an underlying broad component, possibly from a disk. In the others, an apparently narrow Fe-Kα line (even if it is resolved by Chandra) may still be due to the peak of a disk line. To distinguish this scenario from an origin in distant matter requires variability information.
A soft X-ray study of type I active galactic nuclei observed with Chandra high-energy transmission grating spectrometer