Open AccessAngular cross‐correlation of galaxies: a probe of gravitational lensing by large‐scale structure
Author(s) -
Jain Bhuvnesh
Publication year - 1998
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.1365-8711.1998.01378.x
Subject(s) - physics , astrophysics , dark matter , gravitational lensing formalism , weak gravitational lensing , strong gravitational lensing , galaxy , redshift , correlation function (quantum field theory) , gravitational lens , astronomy , optoelectronics , dielectric
The angular cross‐correlation between two galaxy samples separated in redshift is shown to be a useful measure of weak lensing by large‐scale structure. Angular correlations in faint galaxies arise as a result of spatial clustering of the galaxies as well as gravitational lensing by dark matter along the line of sight. The lensing contribution to the two‐point autocorrelation function is typically small compared with the gravitational clustering. However, the cross‐correlation between two galaxy samples is almost unaffected by gravitational clustering provided that their redshift distributions do not overlap. The cross‐correlation is then induced by magnification bias resulting from lensing by large‐scale structure. We compute the expected amplitude of the cross‐correlation for popular theoretical models of structure formation. For two populations with mean redshifts of ≃0.3 and 1, we find a cross‐correlation signal of ≃1 per cent on arcmin scales and ≃3 per cent on scales of a few arcsec. The dependence on the cosmological parameters Ω and Λ, the dark matter power spectrum and the bias factor of the foreground galaxy population is explored.