2001ApJ...561L..23G

We use NIRSPEC, a near-IR spectrometer on Keck II, to obtain moderate-resolution (R=1540) spectroscopy that shows conclusively that the C IV emission line in the z=5.74 quasar SDSSp J104433.04-012502.2 is accompanied by broad, blueshifted C IV absorption. The line has a ``balnicity index'' of 900 km.s<sup>–1</sup> and a rest-frame equivalent width of 13.1±1.3 Å relative to the continuum. This confirms its membership in the class of objects called ``broad absorption line'' (BAL) quasi-stellar objects (QSOs). SDSSp J1044-0125 was previously suggested to be a BAL QSO based on its UV-to-X-ray flux ratio, which is larger than most non-BAL QSOs. The C IV emission is of normal strength, implying a metallicity similar to that found in other, lower redshift, QSOs.