CXO HETGS observations of Seyfert 1 galaxies

We present spectra from NGC 5548 and NGC 3227 obtained using the High-Energy Transmission Grating Spectrometer (HETGS) on board the Chandra X-ray Observatory (CXO). Spectra from two "control" sources, 3C 273 and NGC 3783, are also shown for direct comparison. Here, we concentrate on the strongest, narrow absorption features expected from He- & H-like ions of the abundant elements in the 0.73 keV band. In all cases the data from the Medium- and High-Energy Gratings (MEG & HEG) are shown separately to illustrate their relative quality, and to serve as an independent check on the reality of any features. Our results confirm and illustrate the ionized outflow reported in NGC 5548 by Kaastra et al., and that in NGC 3783 by Kaspi et al. We also confirm a lack of any such material in the case of 3C 273. NGC 3227 was observed during a low, heavily-absorbed state, preventing any definitive statements being made at this time.