2003/11/30 by Masahiro Takada, Martin White · 3 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1086/381870
published as Astrophys.J. 601:L1,2004 · 4 pages, 1 figure. Corrected typo in Equation (6)
openalex publication_date 2004/01/20 · arxiv created 2004/09/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
By obtaining photometric redshift information, tomography allows us to cross-correlate galaxy ellipticities in different source redshift bins. The cross-correlation is nonvanishing because the different bins share much of the foreground mass distribution from which, over gigaparsec scales, the lensing signal is built. If the redshift bins are thick enough, however, the cross-correlations are insensitive to contamination from the intrinsic alignments of galaxies since these fall off rapidly on scales larger than a few tens of megaparsecs. We forecast how lensing tomography using only the cross-power spectra can constrain cosmological parameters compared to tomography including the autospectra. It is shown that the parameter errors are degraded by only (10%) for five or more source redshift bins. Thus, the cross-power spectrum tomography can be a simple, model-independent means of reducing the intrinsic alignment contamination while retaining most of the constraints on cosmology.