[ITAL]J[/ITAL]-Band Spectroscopy of the [CLC][ITAL]z[/ITAL][/CLC] = 5.74 Broad Absorption Line Quasar SDSSp J104433.04−012502.2

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 -1 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.