2010ApJ...708..981H

By analyzing the X-ray spectrum of MCG -6-30-15 obtained with the High Energy Transmission Grating (HETGS) spectrometer on board the Chandra observatory, we identify three kinematically distinct absorption systems; two outflow components intrinsic to MCG -6-30-15, and one local at z = 0. The slow outflow at -100±50 km/s has a large range of ionization manifested by absorption from 24 different charge states of Fe, which enables a detailed reconstruction of the absorption measure distribution (AMD). This AMD spans 5 orders of magnitude in ionization parameter: -1.5 < log ξ < 3.5 (erg/s/cm), with a total column density of N_H= (5.3±0.7)x10²¹/cm2. The fast outflow at -1900±150 km/s has a well-defined ionization parameter with log ξ = 3.82±0.03 (erg/s cm) and column density N_H= 8.1±0.7 x10²²/cm2. Assuming this component is a thin, uniform, spherical shell, it can be estimated to lie within 11 light days of the active galactic nucleus center. The third component, most clearly detected in the lower oxygen charge states O⁺¹-O⁺⁶, has been confused in the past with the fast outflow, but is identified here with local gas (z = 0) and a total column density N_H of a few 10²⁰/cm2. Finally, we exploit the excellent spectral resolution of the HETGS and use the present spectrum to determine the rest-frame wavelengths of oxygen inner-shell lines that were previously uncertain.