Discovery of an Ionized Fe K Edge in the z = 3.91 Broad Absorption Line Quasar APM 08279+5255 with XMM-Newton

摘要

Recent XMM-Newton observations of the high-redshift, lensed, broad absorption line (BAL) quasi-stellar object APM 08279+5255, one of the most luminous objects in the universe, allowed the detection of a high column density absorber (N_H ≈10~23 cm~-2) in the form of a K-shell absorption edge of significantly ionized iron (Fe XV Fe XVIII) and corresponding ionized lower energy absorption. Our findings confirm a basic prediction of phenom- enological geometry models for the BAL outflow and can constrain the size of the absorbing region.