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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 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 catalogue of galaxy photometric redshifts and k-corrections for the Sloan Digital Sky Survey Seven Data Release (SDSS-DR7), available on the World Wide Web. The photometric redshifts were estimated with an artificial neural…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Ana Laura O'Mill , Fernanda Duplancic , Diego García Lambas , Laerte Sodré

Knowing the redshift of galaxies is one of the first requirements of many cosmological experiments, and as it's impossible to perform spectroscopy for every galaxy being observed, photometric redshift (photo-z) estimations are still of…

Instrumentation and Methods for Astrophysics · Physics 2022-03-09 Ben Henghes , Connor Pettitt , Jeyan Thiyagalingam , Tony Hey , Ofer Lahav

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…

Measuring distances of cosmological sources such as galaxies, stars and quasars plays an increasingly critical role in modern cosmology. Obtaining the optical spectrum and consequently calculating the redshift as a distance indicator could…

Astrophysics of Galaxies · Physics 2022-01-13 Aidin Momtaz , Mohammad Hossein Salimi , Soroush Shakeri

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

Traditional photometric redshift methods use only color information about the objects in question to estimate their redshifts. This paper introduces a new method utilizing colors, luminosity, surface brightness, and radial light profile to…

Astrophysics · Physics 2008-11-26 James J. Wray , James E. Gunn

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

The redshifts of galaxies are a key attribute that is needed for nearly all extragalactic studies. Since spectroscopic redshifts require additional telescope and human resources, millions of galaxies are known without spectroscopic…

Astrophysics of Galaxies · Physics 2021-07-21 S. Schuldt , S. H. Suyu , R. Cañameras , S. Taubenberger , T. Meinhardt , L. Leal-Taixé , B. C. Hsieh

Redshift is a key quantity for inferring cosmological model parameters. In photometric redshift estimation, cosmologists use the coarse data collected from the vast majority of galaxies to predict the redshift of individual galaxies. To…

Applications · Statistics 2016-04-07 Rafael Izbicki , Ann B. Lee , Peter E. Freeman

Based on the Sloan Digital Sky Survey Data Release 5 Galaxy Sample, we explore photometric morphology classification and redshift estimation of galaxies using photometric data and known spectroscopic redshifts. An unsupervised method,…

Astrophysics · Physics 2009-11-13 Yanxia Zhang , Lili Li , Yongheng Zhao

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 present and describe a catalog of galaxy photometric redshifts (photo-z's) for the Sloan Digital Sky Survey (SDSS) Data Release 6 (DR6). We use the Artificial Neural Network (ANN) technique to calculate photo-z's and the Nearest Neighbor…

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

We present a catalogue of galaxy photometric redshifts for the Sloan Digital Sky Survey (SDSS) Data Release 12. We use various supervised learning algorithms to calculate redshifts using photometric attributes on a spectroscopic training…

Instrumentation and Methods for Astrophysics · Physics 2019-04-23 Kenny Chong , Abel Yang

Photometric redshifts (photo-z's) provide an alternative way to estimate the distances of large samples of galaxies and are therefore crucial to a large variety of cosmological problems. Among the various methods proposed over the years,…

Instrumentation and Methods for Astrophysics · Physics 2017-06-13 Stefano Cavuoti , Massimo Brescia , Valeria Amaro , Civita Vellucci , Giuseppe Longo , Crescenzo Tortora

We measure photometric redshifts and spectral types for galaxies in the COSMOS survey. We use template fitting technique combined with luminosity function priors and with the option to simultaneously estimate dust extinction (i.e. E(B-V))…

We present redshift probability distributions for galaxies in the SDSS DR8 imaging data. We used the nearest-neighbor weighting algorithm presented in Lima et al. 2008 and Cunha et al. 2009 to derive the ensemble redshift distribution N(z),…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Erin S. Sheldon , Carlos Cunha , Rachel Mandelbaum , J. Brinkmann , Benjamin A. Weaver

We propose a new method to estimate the photometric redshift of galaxies by using the full galaxy image in each measured band. This method draws from the latest techniques and advances in machine learning, in particular Deep Neural…

Instrumentation and Methods for Astrophysics · Physics 2016-06-16 Ben Hoyle

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
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