2016/10/31 by J. Chaves-Montero, Jonás Chaves-Montero, Raúl E. Angulo +2 · 2 citations
Environmental Science · Physics and Astronomy · #Amplitude #Astrophysics #Baryon #Baryon acoustic oscillations #Cluster analysis #Cosmology #Cosmology and Gravitation Theories #Dark energy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Photometric redshift #Physics #Plant Water Relations and Carbon Dynamics #Redshift #Redshift survey #Redshift-space distortions #Spectral density #Statistics #astro-ph.CO
paper · pdf · doi:10.1093/mnras/sty924
19 pages, 15 figures, resubmission. Included full analysis of power spectrum moments l=0, 2, and 4
arxiv created 2018/04/09 · openalex publication_date 2018/04/11 · openalex created_date 2018/04/24 · arxiv updated 2018/06/20 · openalex updated_date 2026/08/05
In the upcoming era of high-precision galaxy surveys, it becomes necessary to understand the impact of redshift uncertainties on cosmological observables. In this paper we explore the effect of sub-percent photometric redshift errors (photo-z errors) on galaxy clustering and baryonic acoustic oscillations (BAOs). Using analytic expressions and results from 1000 N-body simulations, we show how photo-z errors modify the amplitude of moments of the 2D power spectrum, their variances, the amplitude of BAOs, and the cosmological information in them. We find that (a) photo-z errors suppress the clustering on small scales, increasing the relative importance of shot noise, and thus reducing the interval of scales available for BAO analyses; (b) photo-z errors decrease the smearing of BAOs due to non-linear redshift-space distortions (RSDs) by giving less weight to line-of-sight modes; and (c) photo-z errors (and small-scale RSD) induce a scale dependence on the information encoded in the BAO scale, and that reduces the constraining power on the Hubble parameter. Using these findings, we propose a template that extracts unbiased cosmological information from samples with photo-z errors with respect to cases without them. Finally, we provide analytic expressions to forecast the precision in measuring the BAO scale, showing that spectro-photometric surveys will measure the expansion history of the Universe with a precision competitive to that of spectroscopic surveys.