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In Lima et al. 2008 we presented a new method for estimating the redshift distribution, N(z), of a photometric galaxy sample, using photometric observables and weighted sampling from a spectroscopic subsample of the data. In this paper, we…

Astrophysics · Physics 2010-03-18 Carlos E. Cunha , Marcos Lima , Hiroaki Oyaizu , Joshua Frieman , Huan Lin

We present an empirical method for estimating the underlying redshift distribution N(z) of galaxy photometric samples from photometric observables. The method does not rely on photometric redshift (photo-z) estimates for individual…

Astrophysics · Physics 2008-11-26 Marcos Lima , Carlos E. Cunha , Hiroaki Oyaizu , Joshua Frieman , Huan Lin , Erin S. Sheldon

We present a robust method to estimate the redshift of galaxies using Pan-STARRS1 photometric data. Our method is an adaptation of the one proposed by Beck et al. (2016) for the SDSS Data Release 12. It uses a training set of 2313724…

Astrophysics of Galaxies · Physics 2020-10-14 Paula Tarrío , Stefano Zarattini

We present and compare in this paper new photometric redshift catalogs of the galaxies in three public fields: the NTT Deep Field, the HDF-N and the HDF-S. Photometric redshifts have been obtained for thewhole sample, by adopting a $\chi^2$…

Astrophysics · Physics 2009-10-31 A. Fontana , S. D'Odorico , F. Poli , E. Giallongo , S. Arnouts , S. Cristiani , A. Moorwood , P. Saracco

Accurate photometric redshifts are a lynchpin for many future experiments to pin down the cosmological model and for studies of galaxy evolution. In this study, a novel sparse regression framework for photometric redshift estimation is…

Instrumentation and Methods for Astrophysics · Physics 2025-06-03 Ibrahim A. Almosallam , Sam N. Lindsay , Matt J. Jarvis , Stephen J. Roberts

We present a novel way of using neural networks (NN) to estimate the redshift distribution of a galaxy sample. We are able to obtain a probability density function (PDF) for each galaxy using a classification neural network. The method is…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-08 Christopher Bonnett

We present a photometric redshift (photo-$z$) estimation technique for galaxies in the P\lowercase{an}-STARRS1 (PS1) $3\pi $ survey. Specifically, we train and test a regression and a classification Random-Forest (RF) models using…

Astrophysics of Galaxies · Physics 2021-05-28 A. Baldeschi , M. Stroh , R. Margutti , T. Laskar , A. Miller

We present a new training set for estimating empirical photometric redshifts of galaxies, which was created as part of the 2dFLenS project. This training set is located in a 700 sq deg area of the KiDS South field and is randomly selected…

Weak gravitational lensing is a valuable probe of galaxy formation and cosmology. Here we quantify the effects of using photometric redshifts (photo-z) in galaxy-galaxy lensing, for both sources and lenses, both for the immediate goal of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 R. Nakajima , R. Mandelbaum , U. Seljak , J. D. Cohn , R. Reyes , R. Cool

Given multiband photometric data from the SDSS DR6, we estimate galaxy redshifts. We employ a Random Forest trained on color features and spectroscopic redshifts from 80,000 randomly chosen primary galaxies yielding a mapping from color to…

We apply machine learning in the form of a nearest neighbor instance-based algorithm (NN) to generate full photometric redshift probability density functions (PDFs) for objects in the Fifth Data Release of the Sloan Digital Sky Survey (SDSS…

Noisy distance estimates associated with photometric rather than spectroscopic redshifts lead to a mis-estimate of the luminosities, and produce a correlated mis-estimate of the sizes. We consider a sample of early-type galaxies from the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Graziano Rossi , Ravi K. Sheth , Changbom Park

We present a supervised neural network approach to the determination of photometric redshifts. The method was tuned to match the characteristics of the Sloan Digital Sky Survey and it exploits the spectroscopic redshifts provided by this…

We present the methodology and data behind the photometric redshift database of the Sloan Digital Sky Survey Data Release 12 (SDSS DR12). We adopt a hybrid technique, empirically estimating the redshift via local regression on a…

Astrophysics of Galaxies · Physics 2016-06-21 Róbert Beck , László Dobos , Tamás Budavári , Alexander S. Szalay , István Csabai

We developed a Deep Convolutional Neural Network (CNN), used as a classifier, to estimate photometric redshifts and associated probability distribution functions (PDF) for galaxies in the Main Galaxy Sample of the Sloan Digital Sky Survey…

Instrumentation and Methods for Astrophysics · Physics 2018-12-26 Johanna Pasquet , Emmanuel Bertin , Marie Treyer , Stéphane Arnouts , Dominique Fouchez

We present photometric redshift estimates for galaxies used in the weak lensing analysis of the Dark Energy Survey Science Verification (DES SV) data. Four model- or machine learning-based photometric redshift methods -- ANNZ2, BPZ…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-07 C. Bonnett , M. A. Troxel , W. Hartley , A. Amara , B. Leistedt , M. R. Becker , G. M. Bernstein , S. Bridle , C. Bruderer , M. T. Busha , M. Carrasco Kind , M. J. Childress , F. J. Castander , C. Chang , M. Crocce , T. M. Davis , T. F. Eifler , J. Frieman , C. Gangkofner , E. Gaztanaga , K. Glazebrook , D. Gruen , T. Kacprzak , A. King , J. Kwan , O. Lahav , G. Lewis , C. Lidman , H. Lin , N. MacCrann , R. Miquel , C. R. O'Neill , A. Palmese , H. V. Peiris , A. Refregier , E. Rozo , E. S. Rykoff , I. Sadeh , C. Sánchez , E. Sheldon , S. Uddin , R. H. Wechsler , J. Zuntz , T. Abbott , F. B. Abdalla , S. Allam , R. Armstrong , M. Banerji , A. H. Bauer , A. Benoit-Lévy , E. Bertin , D. Brooks , E. Buckley-Geer , D. L. Burke , D. Capozzi , A. Carnero Rosell , J. Carretero , C. E. Cunha , C. B. D'Andrea , L. N. da Costa , D. L. DePoy , S. Desai , H. T. Diehl , J. P. Dietrich , P. Doel , A. Fausti Neto , E. Fernandez , B. Flaugher , P. Fosalba , D. W. Gerdes , R. A. Gruendl , K. Honscheid , B. Jain , D. J. James , M. Jarvis , A. G. Kim , K. Kuehn , N. Kuropatkin , T. S. Li , M. Lima , M. A. G. Maia , M. March , J. L. Marshall , P. Martini , P. Melchior , C. J. Miller , E. Neilsen , R. C. Nichol , B. Nord , R. Ogando , A. A. Plazas , K. Reil , A. K. Romer , A. Roodman , M. Sako , E. Sanchez , B. Santiago , R. C. Smith , M. Soares-Santos , F. Sobreira , E. Suchyta , M. E. C. Swanson , G. Tarle , J. Thaler , D. Thomas , V. Vikram , A. R. Walker

Photometric redshifts of the source galaxies are a key source of systematic uncertainty in the Rubin Observatory Legacy Survey of Space and Time (LSST)'s galaxy clustering and weak lensing analysis, i.e., the $3\times 2$pt analysis. This…

A trustworthy estimate of the redshift distribution $n(z)$ is crucial for using weak gravitational lensing and large-scale structure of galaxy catalogs to study cosmology. Spectroscopic redshifts for the dim and numerous galaxies of…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-27 Alex I. Malz , David W. Hogg

Over the years, photometric redshift estimation (photo-z) has advanced through various methods. This study evaluates four distinct photo-z estimators-ANNz2, BPZ, ENF, and DNF-using the Dark Energy Survey Y3 BAO Sample. Unlike most studies,…

Astrophysics of Galaxies · Physics 2025-07-08 Paula S. Ferreira , Ribamar R. R. Reis

We present a new approach to the problem of estimating the redshift of galaxies from photometric data. The approach uses a genetic algorithm combined with non-linear regression to model the 2SLAQ LRG data set with SDSS DR7 photometry. The…

Instrumentation and Methods for Astrophysics · Physics 2015-04-14 Robert Hogan , Malcolm Fairbairn , Navin Seeburn
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