Large Scale QSO-galaxy correlations for radio loud and optically selected QSO samples

Abstract

We have studied the distribution of $B_J<20.5$ galaxies from the ROE/NRL COSMOS/UKST catalogue around two samples of $z>0.3$ QSOs with similar redshift distributions. The first sample is formed by 144 radio-loud QSOs from the Parkes Catalogue, and the other contains 167 optically selected QSOs extracted from the Large Bright Quasar Survey. It is found that there is a $\approx 99.0$ significance level excess of COSMOS/UKST galaxies around the PKS QSOs, whereas there is a marginal defect of galaxies around the LBQS QSOs. When the distribution of galaxies around both samples is compared, we found that there is an overdensity of galaxies around the PKS sample with respect to the LBQS sample anticorrelated with the distance from the QSOs at a $99.7$ significance level. Although this result apparently agrees with the predictions of the double magnification bias, it is difficult to explain by gravitational lensing effects alone; dust in the foreground galaxies and selection effects in the detection of LBQS QSOs should be taken into account. It has been established that the lines of sight to PKS flat-spectrum QSOs go through significatively higher foreground galaxy densities than the directions to LBQS quasars, what may be partially related with the reported reddening of PKS QSOs.

18 pages, 8 figures, AASTeX, accepted for publication in ApJ

References in corpus (2)

• Maximum-Likelihood Cluster Recontruction
• Cosmological Applications of Gravitational Lensing

Cited by in corpus (15)

• Probing the Universe with Weak Lensing
• The MICE Grand Challenge Lightcone Simulation III: Galaxy lensing mocks from all-sky lensing maps
• Three-Point Correlations in Weak Lensing Surveys: Model Predictions and Applications
• On Statistical Lensing and the Anti-Correlation Between 2dF QSOs and Foreground Galaxies
• Quasar-Galaxy and Galaxy-Galaxy Cross-Correlations: Model Predictions with Realistic Galaxies
• Correlation between galaxies and QSO in the SDSS:na signal from gravitational lensing magnification?
• Quasar-galaxy associations revisited
• Halo model prediction of the cosmic magnification statistics: the full non-linear contribution
• Weak lensing of the high redshift SNIa sample
• The environments of intermediate-redshift QSOs: 0.3 < z < 0.7
• Weak Lensing Induced Correlations Between 1 Jy QSOs and APM Galaxies on Angular Scales of a Degree
• Galaxy-QSO Correlation induced by Weak Gravitational Lensing arising from Large-Scale Structure
• Galaxy-Quasar correlations between APM galaxies and Hamburg-ESO QSOs
• Large-Scale QSO-Galaxy Correlations and Weak Lensing
• Detecting Local and Integrated Relativistic Effects by Multi-Tracing a Single Galaxy Population in Harmonic Space