Improving Galaxy Clustering Measurements with Deep Learning: analysis of the DECaLS DR7 data

Abstract

Robust measurements of cosmological parameters from galaxy surveys rely on our understanding of systematic effects that impact the observed galaxy density field. In this paper we present, validate, and implement the idea of adopting the systematics mitigation method of Artificial Neural Networks for modeling the relationship between the target galaxy density field and various observational realities including but not limited to Galactic extinction, seeing, and stellar density. Our method by construction allows a wide class of models and alleviates over-training by performing k-fold cross-validation and dimensionality reduction via backward feature elimination. By permuting the choice of the training, validation, and test sets, we construct a selection mask for the entire footprint. We apply our method on the extended Baryon Oscillation Spectroscopic Survey (eBOSS) Emission Line Galaxies (ELGs) selection from the Dark Energy Camera Legacy Survey (DECaLS) Data Release 7 and show that the spurious large-scale contamination due to imaging systematics can be significantly reduced by up-weighting the observed galaxy density using the selection mask from the neural network and that our method is more effective than the conventional linear and quadratic polynomial functions. We perform extensive analyses on simulated mock datasets with and without systematic effects. Our analyses indicate that our methodology is more robust to overfitting compared to the conventional methods. This method can be utilized in the catalog generation of future spectroscopic galaxy surveys such as eBOSS and Dark Energy Spectroscopic Instrument (DESI) to better mitigate observational systematics.

31 pages, 25 figures, accepted for publication in MNRAS. Moderate revision throughout the paper. The new version includes a quantitative evaluation of the remaining systematic effects in the DECaLS DR7 data in Summary and Discussion and in Conclusion. Pipeline available at https://github.com/mehdirezaie/SYSNet

References in corpus (63)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Planck 2015 results. XIII. Cosmological parameters
• The Sloan Digital Sky Survey: Technical Summary
• Gaia Data Release 2. Summary of the contents and survey properties
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• An overview of gradient descent optimization algorithms
• LSST: from Science Drivers to Reference Design and Anticipated Data Products
• The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: cosmological analysis of the DR12 galaxy sample
• The 2dF Galaxy Redshift Survey: Spectra and redshifts
• Planck 2018 results. I. Overview and the cosmological legacy of Planck
• HI4PI: A full-sky HI survey based on EBHIS and GASS
• The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey
• The DESI Experiment Part I: Science,Targeting, and Survey Design
• The imprints of primordial non-gaussianities on large-scale structure: scale dependent bias and abundance of virialized objects
• Probing Dark Energy with Baryonic Acoustic Oscillations from Future Large Galaxy Redshift Surveys
• MASTER of the CMB Anisotropy Power Spectrum: A Fast Method for Statistical Analysis of Large and Complex CMB Data Sets
• The WiggleZ Dark Energy Survey: Survey Design and First Data Release
• The clustering of the SDSS-IV extended Baryon Oscillation Spectroscopic Survey DR14 quasar sample: First measurement of Baryon Acoustic Oscillations between redshift 0.8 and 2.2
• How to measure CMB power spectra without losing information
• Why does deep and cheap learning work so well?
• Correlation of CMB with large-scale structure: I. ISW Tomography and Cosmological Implications
• Linear Redshift Distortions: A Review
• The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Analysis of potential systematics
• The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Observational systematics and baryon acoustic oscillations in the correlation function
• Analysis of Systematic Effects and Statistical Uncertainties in Angular Clustering of Galaxies from Early SDSS Data
• nbodykit: an open-source, massively parallel toolkit for large-scale structure
• Cosmic Complementarity: H_0 and Omega_m from Combining CMB Experiments and Redshift Surveys
• Fast estimation of polarization power spectra using correlation functions
• Measuring the galaxy power spectrum with future redshift surveys
• Project Overview of the Beijing-Arizona Sky Survey
• Ameliorating Systematic Uncertainties in the Angular Clustering of Galaxies: A Study using SDSS-III
• Mock galaxy catalogs using the quick particle mesh method
• The SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations at redshift of 0.72 with the DR14 Luminous Red Galaxy Sample
• Clustering of Sloan Digital Sky Survey III Photometric Luminous Galaxies: The Measurement, Systematics and Cosmological Implications
• Dark Energy Survey Year 1 Results: Galaxy clustering for combined probes
• Measuring Dark Energy Properties with Photometrically Classified Pan-STARRS Supernovae. II. Cosmological Parameters
• The Clustering of Galaxies in SDSS-III DR9 Baryon Oscillation Spectroscopic Survey: Constraints on Primordial Non-Gaussianity
• Clustering of quasars in SDSS-IV eBOSS : study of potential systematics and bias determination
• The power of deeper networks for expressing natural functions
• Clustering Analyses of 300,000 Photometrically Classified Quasars--II. The Excess on Very Small Scales
• The SDSS-IV extended Baryonic Oscillation Spectroscopic Survey: Luminous Red Galaxy Target Selection
• No galaxy left behind: accurate measurements with the faintest objects in the Dark Energy Survey
• Galaxy clustering, photometric redshifts and diagnosis of systematics in the DES Science Verification data
• The SDSS-IV Extended Baryon Oscillation Spectroscopic Survey: final Emission Line Galaxy Target Selection
• Estimating the large-scale angular power spectrum in the presence of systematics: a case study of Sloan Digital Sky Survey quasars
• Exact likelihood evaluations and foreground marginalization in low resolution WMAP data
• Excess Clustering on Large Scales in the MegaZ DR7 Photometric Redshift Survey
• Calibration errors unleashed: effects on cosmological parameters and requirements for large-scale structure surveys
• Mapping and simulating systematics due to spatially-varying observing conditions in DES Science Verification data
• Exploiting the full potential of photometric quasar surveys: Optimal power spectra through blind mitigation of systematics
• Systematic effects in large-scale angular power spectra of photometric quasars and implications for constraining primordial nongaussianity
• What is the best way to measure baryonic acoustic oscillations?
• Unbiased methods for removing systematics from galaxy clustering measurements
• The Angular Power Spectra of Photometric SDSS LRGs
• The SDSS-IV eBOSS: emission line galaxy catalogues at z=0.8 and study of systematic errors in the angular clustering
• A map-based method for eliminating systematic modes from galaxy clustering power spectra with application to BOSS
• Higher-Order Angular Galaxy Correlations in the SDSS: Redshift and Color Dependence of non-Linear Bias
• POKER: Estimating the power spectrum of diffuse emission with complex masks and at high angular resolution
• Unbiased contaminant removal for 3D galaxy power spectrum measurements

Cited by in corpus (30)

• DESI Bright Galaxy Survey: Final Target Selection, Design, and Validation
• The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Growth rate of structure measurement from anisotropic clustering analysis in configuration space between redshift 0.6 and 1.1 for the Emission Line Galaxy sample
• The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Large-scale Structure Catalogues and Measurement of the isotropic BAO between redshift 0.6 and 1.1 for the Emission Line Galaxy Sample
• Dark Energy Survey Year 3 Results: Galaxy clustering and systematics treatment for lens galaxy samples
• DESI 2024 V: Full-Shape Galaxy Clustering from Galaxies and Quasars
• Mitigating contamination in LSS surveys: a comparison of methods
• Primordial non-Gaussianity from the Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey I: Catalogue Preparation and Systematic Mitigation
• Angular clustering properties of the DESI QSO target selection using DR9 Legacy Imaging Surveys
• Local primordial non-Gaussianity from the large-scale clustering of photometric DESI luminous red galaxies
• Characterising the target selection pipeline for the Dark Energy Spectroscopic Instrument Bright Galaxy Survey
• Organised Randoms: Learning and correcting for systematic galaxy clustering patterns in KiDS using self-organising maps
• Cross-correlation of Planck CMB lensing with DESI galaxy groups
• Measuring ${\sigma }_8$ using DESI Legacy Imaging Surveys Emission-Line Galaxies and Planck CMB Lensing and the Impact of Dust on Parameter Inference
• Using angular two-point correlations to self-calibrate the photometric redshift distributions of DECaLS DR9
• KiDS-1000: cross-correlation with Planck cosmic microwave background lensing and intrinsic alignment removal with self-calibration
• Baryon Acoustic Oscillations in the projected cross-correlation function between the eBOSS DR16 quasars and photometric galaxies from the DESI Legacy Imaging Surveys
• Clustering of red-sequence galaxies in the fourth data release ofthe Kilo-Degree Survey
• Linear Systematics Mitigation in Galaxy Clustering in the Dark Energy Survey Year 1 Data
• Constraints on primordial non-Gaussianity from the cross-correlation of DESI Luminous Red Galaxies and $Planck$ CMB lensing
• KiDS-Legacy: Angular galaxy clustering from deep surveys with complex selection effects
• The clustering of LRGs in the DECaLS DR8 footprint: distance constraints from baryon acoustic oscillations using photometric redshifts
• Fisher forecast for the BAO measurements from the CSST spectroscopic and photometric galaxy clustering
• On the impact of the galaxy window function on cosmological parameter estimation
• Joint inference of multiplicative and additive systematics in galaxy density fluctuations and clustering measurements
• Spurious correlations between galaxies and multi-epoch image stacks in the DESI Legacy Surveys
• Weak Lensing Reconstruction by Counting DECaLS Galaxies
• Separating Angular and Radial Modes with Spherical-Fourier Bessel Power Spectrum on All Scales and Implications for Systematics Mitigation
• 6x2pt: Forecasting gains from joint weak lensing and galaxy clustering analyses with spectroscopic-photometric galaxy cross-correlations
• Dark Energy Survey Year 3 Results: Galaxy Sample for BAO Measurement
• Systematics mitigation for catalogue-based angular power spectra