Euclid: Photometric redshift calibration with the clustering redshifts technique

Abstract

Aims: The precision of cosmological constraints from imaging surveys hinges on accurately estimating the redshift distribution $n(z)$ of tomographic bins, especially their mean redshifts. We assess the effectiveness of the clustering redshifts technique in constraining Euclid tomographic redshift bins to meet the target uncertainty of $\sigma (⟨z⟩)<0.002(1+z)$. In this work, these mean redshifts are inferred from the small-scale angular clustering of Euclid galaxies, which are distributed into bins with spectroscopic samples localised in narrow redshift slices. Methods: We generate spectroscopic mocks from the Flagship2 simulation for the Baryon Oscillation Spectroscopic Survey (BOSS), the Dark Energy Spectroscopic Instrument (DESI), and Euclid's Near-Infrared Spectrometer and Photometer (NISP) spectroscopic survey. We evaluate and optimise the clustering redshifts pipeline, introducing a new method for measuring photometric galaxy bias (clustering), which is the primary limitation of this technique. Results: We have successfully constrained the means and standard deviations of the redshift distributions for all of the tomographic bins (with a maximum photometric redshift of 1.6), achieving precision beyond the required thresholds. We have identified the main sources of bias, particularly the impact of the 1-halo galaxy distribution, which imposed a minimal separation scale of 1.5 Mpc for evaluating cross-correlations. These results demonstrate the potential of clustering redshifts to meet the precision requirements for Euclid, and we highlight several avenues for future improvements.

arXiv comment31 pages, 24 figures, 2 tables

References in corpus (48)

• emcee: The MCMC Hammer
• The Cosmic Linear Anisotropy Solving System (CLASS) II: Approximation schemes
• The Baryon Oscillation Spectroscopic Survey of SDSS-III
• The Rockstar Phase-Space Temporal Halo Finder and the Velocity Offsets of Cluster Cores
• Revising the Halofit Model for the Nonlinear Matter Power Spectrum
• Why your model parameter confidences might be too optimistic -- unbiased estimation of the inverse covariance matrix
• Euclid. I. Overview of the Euclid mission
• Systematic Errors in Future Weak Lensing Surveys: Requirements and Prospects for Self-Calibration
• Photometric Redshifts for Hyper Suprime-Cam Subaru Strategic Program Data Release 1
• Core Cosmology Library: Precision Cosmological Predictions for LSST
• Calibrating Redshift Distributions Beyond Spectroscopic Limits with Cross-Correlations
• Dark Energy Survey Year 3 Results: Redshift Calibration of the Weak Lensing Source Galaxies
• KiDS-1000 catalogue: Redshift distributions and their calibration
• On using angular cross-correlations to determine source redshift distributions
• Photometric Redshift Calibration with Self Organising Maps
• Euclid. III. The NISP Instrument
• Euclid preparation: X. The Euclid photometric-redshift challenge
• The Extended Baryon Oscillation Spectroscopic Survey: Variability Selection and Quasar Luminosity Function
• SDSS Galaxy Clustering: Luminosity & Colour Dependence and Stochasticity
• Euclid. II. The VIS Instrument
• Recovering Redshift Distributions with Cross-Correlations: Pushing The Boundaries
• How accurate is Limber's equation?
• Dark Energy Survey Year 3 Results: Clustering Redshifts -- Calibration of the Weak Lensing Source Redshift Distributions with redMaGiC and BOSS/eBOSS
• Dark Energy Survey Year 1 Results: Cross-Correlation Redshifts - Methods and Systematics Characterization
• The-wiZZ: Clustering redshift estimation for everyone
• KiDS+VIKING-450: Improved cosmological parameter constraints from redshift calibration with self-organising maps
• Testing KiDS cross-correlation redshifts with simulations
• Euclid: Cosmological forecasts from the void size function
• Dark Energy Survey Year 3 Results: Calibration of Lens Sample Redshift Distributions using Clustering Redshifts with BOSS/eBOSS
• 2dFLenS and KiDS: Determining source redshift distributions with cross-correlations
• The impact of spectroscopic incompleteness in direct calibration of redshift distributions for weak lensing surveys
• Euclid. V. The Flagship galaxy mock catalogue: a comprehensive simulation for the Euclid mission
• Dark Energy Survey Year 3 results: Magnification modeling and impact on cosmological constraints from galaxy clustering and galaxy-galaxy lensing
• Weak Lensing Tomographic Redshift Distribution Inference for the Hyper Suprime-Cam Subaru Strategic Program three-year shape catalogue
• The PAU Survey: Photometric redshifts using transfer learning from simulations
• Perturbation theory for modeling galaxy bias: validation with simulations of the Dark Energy Survey
• Cross-Correlation Redshift Calibration Without Spectroscopic Calibration Samples in DES Science Verification Data
• Observational biases in flux magnification measurements
• The galaxy formation origin of the lensing is low problem
• Euclid preparation: XII. Optimizing the photometric sample of the Euclid survey for galaxy clustering and galaxy-galaxy lensing analyses
• Testing the accuracy of clustering redshift with simulations
• The Impact of Line Misidentification on Cosmological Constraints from Euclid and other Spectroscopic Galaxy Surveys
• Self-calibration and robust propagation of photometric redshift distribution uncertainties in weak gravitational lensing
• The Impact of Anisotropic Redshift Distributions on Angular Clustering
• Dark Energy Survey Year 3 Results: Redshift Calibration of the MagLim Lens Sample from the combination of SOMPZ and clustering and its impact on Cosmology
• Euclid: Calibrating photometric redshifts with spectroscopic cross-correlations
• Euclid: Relativistic effects in the dipole of the 2-point correlation function
• 6x2pt: Forecasting gains from joint weak lensing and galaxy clustering analyses with spectroscopic-photometric galaxy cross-correlations

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