Open AccessThe environments of intermediate‐redshift QSOs: 0.3 < z < 0.7
Author(s) -
Smith R. J.,
Boyle B. J.,
Maddox S. J.
Publication year - 2000
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2000.03225.x
Subject(s) - qsos , physics , astrophysics , redshift , galaxy , astronomy , radio galaxy , quasar
An angular correlation of low significance (2 σ ) is observed between 0.3< z <0.5 QSOs and V 23 galaxies. Overall, the cross‐correlation function between 82 intermediate‐redshift (0.3< z <0.7) X‐ray selected QSOs and V ≲24 galaxies is investigated, but no signal is detected for the z >0.5 QSOs. After converting to an excess of galaxies physically associated with the QSO, this lack of strong correlation is shown to be consistent with the clustering of normal galaxies at the same moderate redshifts. Combined with previous observations, these results imply that the environments of radio‐quiet QSOs do not undergo significant evolution with respect to the galaxy population over a wide range of redshifts (0< z <1.5). This is in marked contrast to the rapid increase in the richness of the environments associated with radio‐loud QSOs over the same redshift range.