Radio - quiet quasar environments at 0 . 5 ≤ z ≤ 0 . 8

We have quantified the galaxy environments around a sample of 0.5 ≤ z ≤ 0.8 radioquiet quasars using the amplitude of the spatial galaxy–quasar correlation function, Bgq. The quasars exist in a wide variety of environments, some sources are located in clusters as rich as Abell class 1–2 clusters, whereas others exist in environments comparable to the field. We find that on average, the quasars prefer poorer clusters of ≈ Abell class 0, which suggests that quasars are biased tracers of mass compared to galaxies. The mean Bgq for the sample is found to be indistinguishable from the mean amplitude for a sample of radio-loud quasars matched in redshift and optical luminosity. These observations are consistent with recent studies of the hosts of radioquiet quasars at low to intermediate redshifts, and suggest that the mechanism for the production of powerful radio jets in radio-loud quasars is controlled by processes deep within the active galactic nucleus itself, and is unrelated to the nature of the hosts or their environments.