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

G. Hasinger·N. Schartel·S. Komossa
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Abstract

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 ($N_H \approx 10^{23}$ cm$^{-2}$) in the form of a K-shell absorption edge of significantly ionized iron (Fe XV - XVIII) and corresponding ionized lower-energy absorption. Our findings confirm a basic prediction of phenomenological geometry models for the BAL outflow and can constrain the size of the absorbing region. The Fe/O abundance of the absorbing material is significantly higher than solar (Fe/O = 2-5), giving interesting constraints on the gas enrichment history in the early Universe.

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G. Hasinger, N. Schartel, S. Komossa. 2002-06-29. Discovery of an ionized Fe-K edge in the z=3.91 Broad Absorption Line Quasar APM 08279+5255 with XMM-Newton. https://doi.org/10.1086/342191

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