Hybrid photometric redshifts for sources in the COSMOS and XMM-LSS fields

Abstract

In this paper we present photometric redshifts for 2.7 million galaxies in the XMM-LSS and COSMOS fields, both with rich optical and near-infrared data from VISTA and HyperSuprimeCam. Both template fitting (using galaxy and Active Galactic Nuclei templates within LePhare) and machine learning (using GPz) methods are run on the aperture photometry of sources selected in the Ks-band. The resulting predictions are then combined using a Hierarchical Bayesian model, to produce consensus photometric redshift point estimates and probability distribution functions that outperform each method individually. Our point estimates have a root mean square error of ~0.08-0.09, and an outlier fraction of ~3-4 percent when compared to spectroscopic redshifts. We also compare our results to the COSMOS2020 photometric redshifts, which contains fewer sources, but had access to a larger number of bands and greater wavelength coverage, finding that comparable photo-z quality can be achieved (for bright and intermediate luminosity sources where a direct comparison can be made). Our resulting redshifts represent the most accurate set of photometric redshifts (for a catalogue this large) for these deep multi-square degree multi-wavelength fields to date.

Published in MNRAS, 15 figures. Photo-z catalogue described in the paper available online here: https://entangled.physics.ox.ac.uk/index.php/s/T1NQAMardpoOQMQ

References in corpus (27)

• EAZY: A Fast, Public Photometric Redshift Code
• COSMOS Photometric Redshifts with 30-bands for 2-deg2
• 3D-HST WFC3-selected Photometric Catalogs in the Five CANDELS/3D-HST Fields: Photometry, Photometric Redshifts and Stellar Masses
• UltraVISTA: a new ultra-deep near-infrared survey in COSMOS
• COSMOS2020: A panchromatic view of the Universe to $z\sim 10$ from two complementary catalogs
• Galaxies in the Hubble Ultra Deep Field: I. Detection, Multiband Photometry, Photometric Redshifts, and Morphology
• Photometric redshift and classification for the XMM-COSMOS sources
• The Zurich Extragalactic Bayesian Redshift Analyzer (ZEBRA) and its first application: COSMOS
• A lack of evolution in the very bright-end of the galaxy luminosity function from z = 8-10
• Estimating the Redshift Distribution of Faint Galaxy Samples
• Photometric Redshifts in the IRAC Shallow Survey
• Cosmic Web of Galaxies in the COSMOS Field: Public Catalog and Different Quenching for Centrals and Satellites
• All-purpose, all-sky photometric redshifts for the Legacy Imaging Surveys Data Release 8
• Photometric redshifts for the next generation of deep radio continuum surveys - I: Template fitting
• METAPHOR: A machine learning based method for the probability density estimation of photometric redshifts
• Estimating Luminosities and Stellar Masses of Galaxies Photometrically without Determining Redshifts
• Clustering-based Redshift Estimation: Comparison to Spectroscopic Redshifts
• The clustering and bias of radio-selected AGN and star-forming galaxies in the COSMOS field
• The XMM-LSS survey: the Class 1 cluster sample over the extended 11 deg${}^2$ and its spatial distribution
• Improving Photometric Redshift Estimation using GPz: size information, post processing and improved photometry
• Radio and Far-IR Emission Associated with a Massive Star-forming Galaxy Candidate at z$\simeq$6.8: A Radio-Loud AGN in the Reionization Era?
• BIRTH of the COSMOS Field: Primordial and Evolved Density Reconstructions During Cosmic High Noon
• The LSST-DESC 3x2pt Tomography Optimization Challenge
• Augmenting machine learning photometric redshifts with Gaussian mixture models
• How not to obtain the redshift distribution from probabilistic redshift estimates: Under what conditions is it not inappropriate to estimate the redshift distribution N(z) by stacking photo-z PDFs?
• The sensitivity of GPz estimates of photo-z posterior PDFs to realistically complex training set imperfections
• Statistical strong lensing. IV. Inferences with no individual source redshifts

Cited by in corpus (11)

• MIGHTEE: the nature of the radio-loud AGN population
• Optimized Photometric Redshifts for the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS)
• Probing magnetic fields in the circumgalactic medium using polarization data from MIGHTEE
• Spectral age distribution for radio-loud active galaxies in the XMM-LSS field
• $Spitzer$-selected $z>1.3$ protocluster candidates in the LSST Deep Drilling Fields
• MIGHTEE: exploring the relationship between spectral index, redshift and radio luminosity
• Exploring the physical properties of Type II Quasar candidates at intermediate redshifts with CIGALE
• The superMIGHTEE project: MeerKAT and GMRT Together to Unveil the Deep Radio Sky
• The Jet Paths of Radio AGN and their Cluster Weather
• MIGHTEE: The dark matter haloes, duty cycle and mechanical feedback from radio-AGN up to $z\sim 2.5$
• TOPz: Photometric redshifts using template fitting applied to the GAMA survey