A joint analysis for cosmology and photometric redshift calibration using cross-correlations. Issue 3 (22nd November 2016)

• Record Type: Journal Article
• Authors: McLeod, Michael; Balan, Sreekumar T.; Abdalla, Filipe B.
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 466:Issue 3(2017)
• Page Start: 3558
• Page End: 3568
• Publication Date: 2016-11-22
• Subjects: surveys -- galaxies: photometry -- cosmological parameters -- large-scale structure of Universe; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stw2989
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: We present a method of calibrating the properties of photometric redshift bins as part of a larger nested sampling analysis for the inference of cosmological parameters. The redshift bins are characterized by their mean and variance, which are varied as free parameters and marginalized over when obtaining the cosmological parameters. We demonstrate that the likelihood function for cross-correlations in an angular power spectrum framework tightly constrains the properties of bins such that they may be well determined, reducing their influence on cosmological parameters and avoiding the bias from poorly estimated redshift distributions. We demonstrate that even with only three photometric and three spectroscopic bins, we can recover accurate estimates of the mean redshift of a bin to within Δμ ≈ 3–4 × 10 −3 and the width of the bin to Δσ ≈ 1 × 10 −3 for galaxies near z = 1. This indicates that we may be able to bring down the photometric redshift errors to a level which is in line with the requirements for the next generation of cosmological experiments.