SIMBAD references

We quantify the galaxy environments around a sample of 0.5≤z≤0.8 radio-quiet quasars using the amplitude of the spatial galaxy-quasar correlation function, B_gq. 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 with galaxies. The mean B_gq 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 radio-quiet 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.