QSO lensing magnification associated with galaxy groups

Abstract

We simulated both the matter and light (galaxy) distributions in a wedge of the universe and calculated the gravitational lensing magnification caused by the mass along the line of sight of galaxies and galaxy groups identified in sky surveys. A large volume redshift cone containing cold dark matter particles mimics the expected cosmological matter distribution in a flat universe with low matter density and a cosmological constant. We generate a mock galaxy catalogue from the matter distribution and identify thousands of galaxy groups in the luminous sky projection. We calculate the expected magnification around galaxies and galaxy groups and then the induced QSO-lens angular correlation due to magnification bias. This correlation is an observable and can be used to estimate the average mass of the lens population and also make cosmological inferences. We also use analytic calculations and various analysis to compare the observational results with theoretical expectations for the cross-correlation between faint QSOs from the 2dF Survey and nearby galaxies and groups from the APM and SDSS EDR. The observed QSO-lens anti-correlations are stronger than the predictions for the cosmological model used. This suggests that there could be unknown systematic errors in the observations and data reduction, or that the model used is not adequate. If the observed signal is assumed to be solely due to gravitational lensing then the lensing is stronger than expected, due to more massive galactic structures or more efficient lensing than simulated.

11 pages. Version accepted by MNRAS

References in corpus (20)

• A Universal Density Profile from Hierarchical Clustering
• Weak Gravitational Lensing
• Nonlinear evolution of cosmological power spectra
• The 2dF QSO Redshift Survey - XII. The spectroscopic catalogue and luminosity function
• Ray Tracing Simulations of Weak Lensing by Large-Scale Structure
• Simulating weak lensing by large scale structure
• A survey for large image-separation lensed quasars
• On Statistical Lensing and the Anti-Correlation Between 2dF QSOs and Foreground Galaxies
• Improving the Accuracy of Cosmic Magnification Statistics
• Testing deprojection algorithms on mock angular catalogues: Evidence for a break in the power spectrum
• Quasar-Galaxy and Galaxy-Galaxy Cross-Correlations: Model Predictions with Realistic Galaxies
• Measuring Omega_0 with higher-order Quasar-Galaxy Correlations induced by Weak Lensing
• The 2dF QSO Redshift Survey - X. Lensing of Background QSOs by Galaxy Groups
• QSO-galaxy correlations due to weak lensing in arbitrary Friedmann-Lemaitre cosmologies
• The Power Spectrum of Rich Clusters on Near Gigaparsec Scales
• Statistical lensing of faint QSOs by galaxy clusters
• Halo model prediction of the cosmic magnification statistics: the full non-linear contribution
• Weak lensing correlations in open and flat universes
• Shear and magnification angular power spectra and higher-order moments from weak gravitational lensing
• Galaxy-QSO Correlation induced by Weak Gravitational Lensing arising from Large-Scale Structure

Cited by in corpus (4)

• The CFHTLS Strong Lensing Legacy Survey: I. Survey overview and T0002 release sample
• LIGER: mock relativistic light-cones from Newtonian simulations
• QSO Lensing Magnification: A Comparison of 2QZ and SDSS Results
• The Effect of Lensing on the Large-Scale CMB Anisotropy