Galaxy Clustering around Nearby Luminousquasars 1

We examine the clustering of galaxies around a sample of 20 luminous low redshift (z < 0:30) quasars observed with the Wide Field Camera-2 on the Hubble Space Telescope. The HST resolution makes possible galaxy identiication brighter than V = 23:5 and as close as 2 00 to the quasar. We nd a signiicant enhancement of galaxies within a projected separation of < 100 h ?1 kpc of the quasars. If we model the qso/galaxy correlation function as a power law with a slope given by the galaxy/galaxy correlation function, we nd that the ratio of the qso/galaxy to galaxy/galaxy correlation functions is 3:8 0:8. The galaxy counts within r < 15 h ?1 kpc of the quasars are too high for the density proole to have an appreciable core radius (> 100 h ?1 kpc). Our results reinforce the idea that low redshift quasars are located preferentially in groups of 10{20 galaxies rather than in rich clusters. We see no signiicant diierence in the clustering amplitudes derived from radio-loud and radio-quiet subsamples.