2007MNRAS.374.1506B

Quasars representative of the populous faint end of the luminosity function are dim with m ∼ 24 at intermediate redshift, and traditional ground-based surveys for such faint quasars often suffer from severe contamination by compact faint galaxies. In order to limit the latter morphological contamination, we are conducting a combined multicolour and morphological survey for faint quasars, to B < 24.5 and z < 2.1, using archival Hubble Space Telescope (HST) images. Our previous work provided a similar survey of the Groth-Westphal Strip. Here, we extend our survey to an additional 31 high galactic latitude (pure parallel) fields that cover another 0.04 deg² of sky, imaged with the superb 0.1-arcsec spatial resolution of the Wide Field Planetary Camera 2 aboard HST. In our expanded survey, we identify an additional 19 high-likelihood ultraviolet-excess quasar candidates having stellar or unresolved nucleus plus host-galaxy morphology, and yielding a cumulative quasar surface density of 511⁺¹⁴²_–113/deg2 to B < 24.5 and z < 2.1. Our results are in reasonable agreement both with our own earlier survey of the Groth-Westphal Strip and with other faint quasar surveys that utilize very different selection approaches.