The Impact of Tomographic Redshift Bin Width Errors on Cosmological Probes

Abstract

Systematic errors in the galaxy redshift distribution $n(z)$ can propagate to systematic errors in the derived cosmology. We characterize how the degenerate effects in tomographic bin widths and galaxy bias impart systematic errors on cosmology inference using observational data from the Deep Lens Survey. For this we use a combination of galaxy clustering and galaxy-galaxy lensing. We present two end-to-end analyses from the catalogue level to parameter estimation. We produce an initial cosmological inference using fiducial tomographic redshift bins derived from photometric redshifts, then compare this with a result where the redshift bins are empirically corrected using a set of spectroscopic redshifts. We find that the derived parameter $S_8\equiv {\sigma }_8({\Omega }_m/.3{)}^{1/2}$ goes from $.841_{-.061}^{+0.062}$ to $.739_{-.050}^{+.054}$ upon correcting the n(z) errors in the second method.

13 pages, 9 figures

References in corpus (7)

• Why your model parameter confidences might be too optimistic -- unbiased estimation of the inverse covariance matrix
• Galaxies in the Hubble Ultra Deep Field: I. Detection, Multiband Photometry, Photometric Redshifts, and Morphology
• Modelling baryonic feedback for survey cosmology
• Principal Component Analysis of the Time- and Position-Dependent Point Spread Function of the Advanced Camera for Surveys
• Dark Energy Survey Year 1 Results: Multi-Probe Methodology and Simulated Likelihood Analyses
• An Improved Photometric Calibration of the Sloan Digital Sky Survey Imaging Data
• Dark energy constraints and correlations with systematics from CFHTLS weak lensing, SNLS supernovae Ia and WMAP5