2014/01/31 by Alex Hall, A Hall, Andy Taylor · 1 citation
Physics and Astronomy · #Amplitude #Astrophysics #COSMIC cancer database #Cosmic background radiation #Cosmic microwave background #Cosmology and Gravitation Theories #Cross-correlation #Galaxies: Formation, Evolution, Phenomena #Galaxy #Optics #Physics #Radio Astronomy Observations and Technology #Redshift #Statistics #Weak gravitational lensing #astro-ph.CO
paper · pdf · doi:10.1093/mnrasl/slu094
5 pages, 4 figures; Published by MNRAS Letters. Minor corrections to match the published version
openalex publication_date 2014/07/16 · arxiv created 2014/07/18 · arxiv updated 2014/07/22 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Abstract We demonstrate that the intrinsic alignment of galaxies with large-scale tidal fields sources an extra contribution to the recently detected cross-correlation of galaxy shear and weak lensing of the microwave background. The extra term is the analogy of the ‘GI’ term in standard cosmic shear studies, and results in a reduction in the amplitude of the cross-correlation. We compute the intrinsic alignment contribution in linear and non-linear theory, and show that it can be at roughly the 15 per cent level for the Canada–France–Hawaii Telescope Stripe 82 redshift distribution, if the canonical amplitude of intrinsic alignments is assumed. The new term can therefore potentially reconcile the apparently low value of the measured cross-correlation with standard Λ cold dark matter. We discuss various small-scale effects in the signal and the dependence on the source redshift distribution. We discuss the exciting possibility of self-calibrating intrinsic alignments with a joint analysis of cosmic shear and weak lensing of the microwave background.