English
Related papers

Related papers: METAPHOR: A machine learning based method for the …

200 papers

Photometric redshifts are estimated on the basis of template scenarios with the help of the code ZPEG, an extension of the galaxy evolution model PEGASE.2 and available on the PEGASE web site. The spectral energy distribution (SED)…

Astrophysics · Physics 2009-11-07 Damien Le Borgne , Brigitte Rocca-Volmerange

In this paper we present photometric redshift (photo-$z$) estimates for the Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Surveys, currently the most sensitive optical survey covering the majority of the extra-galactic sky. Our…

Astrophysics of Galaxies · Physics 2022-03-14 Kenneth J. Duncan

Photometric redshift estimation algorithms are often based on representative data from observational campaigns. Data-driven methods of this type are subject to a number of potential deficiencies, such as sample bias and incompleteness.…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-06 Nesar Ramachandra , Jonás Chaves-Montero , Alex Alarcon , Arindam Fadikar , Salman Habib , Katrin Heitmann

We present a method, PhotoWeb, for estimating photometric redshifts of individual galaxies, and their equivalent distance, with megaparsec and even sub-megaparsec accuracy using the Cosmic Web as a constraint over photo-z estimates.…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-30 Miguel A. Aragon-Calvo , Rien van de Weygaert , Bernard J. T. Jones , Bahram Mobasher

Machine learning (ML) is a standard approach for estimating the redshifts of galaxies when only photometric information is available. ML photo-z solutions have traditionally ignored the morphological information available in galaxy images…

Instrumentation and Methods for Astrophysics · Physics 2019-09-25 Kristen Menou

Photometric redshift estimation is an indispensable tool of precision cosmology. One problem that plagues the use of this tool in the era of large-scale sky surveys is that the bright galaxies that are selected for spectroscopic observation…

Instrumentation and Methods for Astrophysics · Physics 2017-07-18 Peter E. Freeman , Rafael Izbicki , Ann B. Lee

In this paper we explore the applicability of the unsupervised machine learning technique of Self Organizing Maps (SOM) to estimate galaxy photometric redshift probability density functions (PDFs). This technique takes a spectroscopic…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 M. Carrasco Kind , R. J. Brunner

We present results exploring the role that probabilistic deep learning models can play in cosmology from large-scale astronomical surveys through photometric redshift (photo-z) estimation. Photo-z uncertainty estimates are critical for the…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-20 Evan Jones , Tuan Do , Bernie Boscoe , Jack Singal , Yujie Wan , Zooey Nguyen

Photo-z algorithms that utilize SED template fitting have matured, and are widely adopted for use on high-redshift near-infrared data that provides a unique window into the early universe. Alternative photo-z methods have been developed,…

Instrumentation and Methods for Astrophysics · Physics 2026-02-04 Grant Merz , Ming-Yang Zhuang , Junyao Li , Qian Yang , Yue Shen , Xin Liu , John Franklin Crenshaw

Quasar photometric redshifts are essential for studying cosmology and large-scale structures. However, their complex spectral energy distributions cause significant redshift-color degeneracy, limiting the accuracy of traditional methods. To…

Astrophysics of Galaxies · Physics 2025-12-19 Jianzhen Chen , Zhijian Luo , Liping Fu , Zhu Chen , Hubing Xiao , Shaohua Zhang , Chenggang Shu

We apply instance-based machine learning in the form of a k-nearest neighbor algorithm to the task of estimating photometric redshifts for 55,746 objects spectroscopically classified as quasars in the Fifth Data Release of the Sloan Digital…

We present a star/galaxy classification for the Southern Photometric Local Universe Survey (S-PLUS), based on a Machine Learning approach: the Random Forest algorithm. We train the algorithm using the S-PLUS optical photometry up to $r$=21,…

Wide field images taken in several photometric bands allow simultaneous measurement of redshifts for thousands of galaxies. A variety of algorithms to make this measurement have appeared in the last few years, the majority of which can be…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-11 Juan De Vicente , Eusebio Sánchez , Ignacio Sevilla

The scientific value of the next generation of large continuum surveys would be greatly increased if the redshifts of the newly detected sources could be rapidly and reliably estimated. Given the observational expense of obtaining…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-03 S. J. Curran , J. P. Moss , Y. C. Perrott

Large-scale surveys make huge amounts of photometric data available. Because of the sheer amount of objects, spectral data cannot be obtained for all of them. Therefore it is important to devise techniques for reliably estimating physical…

Instrumentation and Methods for Astrophysics · Physics 2017-03-22 Kristoffer Stensbo-Smidt , Fabian Gieseke , Christian Igel , Andrew Zirm , Kim Steenstrup Pedersen

In the era of large sky surveys, photometric redshifts (photo-z) represent crucial information for galaxy evolution and cosmology studies. In this work, we propose a new Machine Learning (ML) tool called Galaxy morphoto-Z with neural…

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

Photometric redshift estimation is a key requirement for modern large-area surveys, where spectroscopic measurements are observationally prohibitive. Seyfert II galaxies provide a particularly challenging test case due to the combined…

Astrophysics of Galaxies · Physics 2026-04-23 Uzay Aydin

We present ANNz2, a new implementation of the public software for photometric redshift (photo-z) estimation of Collister and Lahav (2004), which now includes generation of full probability distribution functions (PDFs). ANNz2 utilizes…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-24 Iftach Sadeh , Filipe B. Abdalla , Ofer Lahav

We present a new approach to automate the spectroscopic redshift reliability assessment based on machine learning (ML) and characteristics of the redshift probability density function (PDF). We propose to rephrase the spectroscopic redshift…

Instrumentation and Methods for Astrophysics · Physics 2018-04-04 S. Jamal , V. Le Brun , O. Le Fèvre , D. Vibert , A. Schmitt , C. Surace , Y. Copin , B. Garilli , M. Moresco , L. Pozzetti