The second APM UKST colour survey for z > 4 quasars

We present the spectra, positions, and finding charts for 31 bright (R < 19 .3) colour-selected quasars covering the redshift range z = 3.85-4.78, with four having redshifts z > 4.5. The majority are in the southern sky (delta < -25<degrees>). The quasar candidates were selected for their red (B-J - R greater than or similar to 2.5) colours from UK or POSSII Schmidt Plates scanned at the Automated Plate Measuring (APM) facility in Cambridge. Low-r esolution (greater than or similar to 10 Angstrom) spectra were obtained to identify the quasars, primarily at the Las Campanas Observatory. The highe st redshift quasar in our survey is at z approximate to 4.8 (R = 18.7) and its spectrum shows a damped Ly alpha absorption system z = 4.46. This is cu rrently the highest redshift damped Ly alpha absorber detected. Five of the se quasars exhibit intrinsic broad absorption line features. Combined with the previously published results from the first part of the APM United King dom Schmidt Telescope (UKST) survey we have now surveyed a total of similar to 8000 deg(2) of sky i.e. 40 per cent of the high galactic latitude (\b\ > 30 degrees) sky, resulting in 59 optically selected quasars in the redshi ft range 3.85 to 4.78; 49 of which have z greater than or equal to 4.00.