English
Related papers

Related papers: Photometric redshift estimation via deep learning

200 papers

We release photometric redshifts, reaching $\sim$0.7, for $\sim$14M galaxies at $r\leq 20$ in the 11,500 deg$^2$ of the SDSS north and south galactic caps. These estimates were inferred from a convolution neural network (CNN) trained on…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-16 M. Treyer , R. Ait-Ouahmed , J. Pasquet , S. Arnouts , E. Bertin , D. Fouchez

We present METAPHOR (Machine-learning Estimation Tool for Accurate PHOtometric Redshifts), a method able to provide a reliable PDF for photometric galaxy redshifts estimated through empirical techniques. METAPHOR is a modular workflow,…

Instrumentation and Methods for Astrophysics · Physics 2017-06-14 Valeria Amaro , Stefano Cavuoti , Massimo Brescia , Civita Vellucci , Crescenzo Tortora , Giuseppe Longo

We combine in a single framework the two complementary benefits of chi^2-template fits and empirical training sets used e.g. in neural nets: chi^2 is more reliable when its probability density functions (PDFs) are inspected for multiple…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 Christian Wolf

Expanding upon the work of Way and Srivastava 2006 we demonstrate how the use of training sets of comparable size continue to make Gaussian process regression (GPR) a competitive approach to that of neural networks and other least-squares…

Instrumentation and Methods for Astrophysics · Physics 2009-11-09 M. J. Way , L. V. Foster , P. R. Gazis , A. N. Srivastava

From SDSS commissioning photometric and spectroscopic data, we investigate the utility of photometric redshift techniques to the task of estimating QSO redshifts. We consider empirical methods (e.g. nearest-neighbor searches and polynomial…

The recently initiated SPHEREx and 7DS surveys will deliver low-resolution spectra ($R\approx 30-130$) for hundreds of millions of galaxies over the optical to near-infrared range ($0.4-5.0\mu m$), covering a wide sky area without sample…

Cross-correlation techniques provide a promising avenue for calibrating photometric redshifts and determining redshift distributions using spectroscopy which is systematically incomplete (e.g., current deep spectroscopic surveys fail to…

Instrumentation and Methods for Astrophysics · Physics 2012-01-20 Daniel J. Matthews , Jeffrey A. Newman

The development of the state-of-the-art telescopic systems capable of performing expansive sky surveys such as the Sloan Digital Sky Survey, Euclid, and the Rubin Observatory's Legacy Survey of Space and Time (LSST) has significantly…

We present a simple, efficient and robust approach to improve cosmological redshift measurements. The method is based on the presence of a reference sample for which a precise redshift number distribution (dN/dz) can be obtained for…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-13 Nicolas Tejos , Aldo Rodriguez-Puebla , Joel R. Primack

We demonstrate that observations lacking reliable redshift information, such as photometric and radio continuum surveys, can produce robust measurements of cosmological parameters when empowered by clustering-based redshift estimation. This…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-10 Ely D. Kovetz , Alvise Raccanelli , Mubdi Rahman

Photometric redshifts are essential in studies of both galaxy evolution and cosmology, as they enable analyses of objects too numerous or faint for spectroscopy. The Rubin Observatory, Euclid, and Roman Space Telescope will soon provide a…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-28 Jeffrey A. Newman , Daniel Gruen

Computational image reconstruction algorithms generally produce a single image without any measure of uncertainty or confidence. Regularized Maximum Likelihood (RML) and feed-forward deep learning approaches for inverse problems typically…

Machine Learning · Computer Science 2020-12-18 He Sun , Katherine L. Bouman

Photometric galaxy surveys constitute a powerful cosmological probe but rely on the accurate characterization of their redshift distributions using only broadband imaging, and can be very sensitive to incomplete or biased priors used for…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-30 Alex Alarcon , Carles Sánchez , Gary M. Bernstein , Enrique Gaztañaga

Photometric redshifts of galaxies obtained by multi-wavelength data are widely used in photometric surveys because of its high efficiency. Although various methods have been developed, template fitting is still adopted as one of the most…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-11 Yicheng Li , Liping Fu , Zhu Chen , Zhijian Luo , Wei Du , Yan Gong , Xianmin Meng , Junhao Lu , Zhirui Tang , Pengfei Chen , Shaohua Zhang , Chenggang Shu , Xingchen Zhou , Zuhui Fan

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 uncertainty in the redshift distributions of galaxies has a significant potential impact on the cosmological parameter values inferred from multi-band imaging surveys. The accuracy of the photometric redshifts measured in these surveys…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-05 Augusta Abrahamse , Lloyd Knox , Samuel Schmidt , Paul Thorman , J. Anthony Tyson , Hu Zhan

The accurate estimation of photometric redshifts plays a crucial role in accomplishing science objectives of the large survey projects. The template-fitting and machine learning are the two main types of methods applied currently. Based on…

Machine learning techniques, specifically the k-nearest neighbour algorithm applied to optical band colours, have had some success in predicting photometric redshifts of quasi-stellar objects (QSOs): Although the mean of differences between…

Instrumentation and Methods for Astrophysics · Physics 2020-01-29 S. J. Curran

We seek to improve the accuracy of joint galaxy photometric redshift estimation and spectral energy distribution (SED) fitting. By simulating different sources of uncorrected systematic errors, we demonstrate that if the uncertainties on…

Instrumentation and Methods for Astrophysics · Physics 2015-06-24 Viviana Acquaviva , Anand Raichoor , Eric Gawiser