The effect of photometric redshift uncertainties on galaxy clustering and baryonic acoustic oscillations

Abstract

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 (BAO). 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 BAO, 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 BAO due to non-linear redshift-space distortions (RSD) 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.

19 pages, 15 figures, resubmission. Included full analysis of power spectrum moments l=0, 2, and 4

References in corpus (13)

• COSMOS Photometric Redshifts with 30-bands for 2-deg2
• Why your model parameter confidences might be too optimistic -- unbiased estimation of the inverse covariance matrix
• Improving Cosmological Distance Measurements by Reconstruction of the Baryon Acoustic Peak
• Nonlinear Evolution of Baryon Acoustic Oscillations
• The detectability of baryonic acoustic oscillations in future galaxy surveys
• `Eppur Si Muove': On The Motion of the Acoustic Peak in the Correlation Function
• Calibrating the Baryon Oscillation Ruler for Matter and Halos
• Constraining Anisotropic Baryon Oscillations
• Accurate estimators of power spectra in N-body simulations
• On Removing Interloper Contamination from Intensity Mapping Power Spectrum Measurements
• New constraints on ${\sigma }_8$ from a joint analysis of stacked gravitational lensing and clustering of galaxy clusters
• Mock galaxy redshift catalogues from simulations: implications for Pan-STARRS1
• ELDAR, a new method to identify AGN in multi-filter surveys: the ALHAMBRA test-case

Cited by in corpus (24)

• The BACCO Simulation Project: Exploiting the full power of large-scale structure for cosmology
• The miniJPAS survey: a preview of the Universe in 56 colours
• The LSST DESC DC2 Simulated Sky Survey
• Can redshift errors bias measurements of the Hubble Constant?
• The miniJPAS survey: the photometric redshift catalogue
• Optimized Clustering Estimators for BAO Measurements Accounting for Significant Redshift Uncertainty
• The Impact of Observing Strategy on Cosmological Constraints with LSST
• Power spectrum modelling of galaxy and radio intensity maps including observational effects
• Developing a unified pipeline for large-scale structure data analysis with angular power spectra -- I. The importance of redshift-space distortions for galaxy number counts
• Measuring the evolution of intergalactic gas from z=0 to 5 using the kinematic Sunyaev-Zel'dovich effect
• Lyman-alpha emitters in a cosmological volume II: the impact of the intergalactic medium
• Dark Energy Survey Year 3 Results: Measurement of the Baryon Acoustic Oscillations with Three-dimensional Clustering
• Photometric Redshift Estimation with Galaxy Morphology using Self-Organizing Maps
• Clustering with general photo-$z$ uncertainties: Application to Baryon Acoustic Oscillations
• TOPz: Photometric redshifts for J-PAS
• Density Weighted Angular Redshift Fluctuations: a New Cosmological Observable
• DISCO-DJ I: a differentiable Einstein-Boltzmann solver for cosmology
• Angular Correlation Function Estimators Accounting for Contamination from Probabilistic Distance Measurements
• Optimizing galaxy samples for clustering measurements in photometric surveys
• The miniJPAS survey: Maximising the photo-z accuracy from multi-survey datasets with probability conflation
• Improving NASA/IPAC Extragalactic Database Redshift Calculations
• Clustering redshifts with the 21cm-galaxy cross-bispectrum
• Relativistic Angular Redshift Fluctuations embedded in Large Scale Varying Gravitational Potentials
• Baryon Acoustic Oscillations in tomographic Angular Density and Redshift Fluctuations