2002/08/31 by Lindsay King, L. King, P. Schneider +1 · 2 citations
Physics and Astronomy · #Amplitude #Astronomy and Astrophysical Research #COSMIC cancer database #Correlation function (quantum field theory) #Cosmology #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Matter power spectrum #Photometric redshift #Redshift #Weak gravitational lensing #astro-ph
paper · pdf · doi:10.1051/0004-6361:20021372
published as Astron.Astrophys. 396 (2002) 411-418 · 17 pages, 5 figures, Accepted in A&A, incorporates minor Comments from referee
arxiv created 2002/09/23 · openalex publication_date 2002/12/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Cosmological weak lensing gives rise to correlations in the ellipticities of faint galaxies. This cosmic shear signal depends upon the matter power spectrum, thus providing a means to constrain cosmological parameters. It has recently been proposed that intrinsic alignments arising at the epoch of galaxy formation can also contribute significantly to the observed correlations, the amplitude increasing with decreasing survey depth. Here we consider the two-point shear correlation function, and demonstrate that photometric redshift information can be used to suppress the intrinsic signal; at the same time Poisson noise is increased, due to a decrease in the effective number of galaxy pairs. The choice to apply such a redshift-depending weighting will depend on the characteristics of the survey in question. In surveys with , although the lensing signal dominates, the measurement error bars may soon become smaller than the intrinsic alignment signal; hence, in order not to be dominated by systematics, redshift information in cosmic shear statistics will become a necessity. We discuss various aspects of this.