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Related papers: Co-SOM: Co-training for photometric redshift estim…

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We use a contrastive self-supervised learning framework to estimate distances to galaxies from their photometric images. We incorporate data augmentations from computer vision as well as an application-specific augmentation accounting for…

Instrumentation and Methods for Astrophysics · Physics 2021-01-13 Md Abul Hayat , Peter Harrington , George Stein , Zarija Lukić , Mustafa Mustafa

In a companion paper, we proposed combining large numbers of "fuzzy archetypes" with Self-Organizing Maps (SOMs) to derive photometric redshifts in a data-driven way. In this paper, we investigate the performance of several sampling…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-29 Joshua S. Speagle , Daniel J. Eisenstein

Photometric redshifts (photo-z's) are fundamental in galaxy surveys to address different topics, from gravitational lensing and dark matter distribution to galaxy evolution. The Kilo Degree Survey (KiDS), i.e. the ESO public survey on the…

We present a new approach to obtaining photometric redshifts using a kernel learning technique called Support Vector Machines (SVMs). Unlike traditional spectral energy distribution fitting, this technique requires a large and…

Astrophysics · Physics 2009-11-10 Yogesh Wadadekar

Cosmological galaxy surveys aim at mapping the largest volumes to test models with techniques such as cluster abundance, cosmic shear correlations or baryon acoustic oscillations (BAO), which are designed to be independent of galaxy bias.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 E. Gaztanaga , M. Eriksen , M. Crocce , F. Castander , P. Fosalba , P. Marti , R. Miquel , A. Cabre

Characterization of the redshift distribution of ensembles of galaxies is pivotal for large scale structure cosmological studies. In this work, we focus on improving the Self-Organizing Map (SOM) methodology for photometric redshift…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-05 A. Campos , B. Yin , S. Dodelson , A. Amon , A. Alarcon , C. Sánchez , G. M. Bernstein , G. Giannini , J. Myles , S. Samuroff , O. Alves , F. Andrade-Oliveira , K. Bechtol , M. R. Becker , J. Blazek , H. Camacho , A. Carnero Rosell , M. Carrasco Kind , R. Cawthon , C. Chang , R. Chen , A. Choi , J. Cordero , C. Davis , J. DeRose , H. T. Diehl , C. Doux , A. Drlica-Wagner , K. Eckert , T. F. Eifler , J. Elvin-Poole , S. Everett , X. Fang , A. Ferté , O. Friedrich , M. Gatti , D. Gruen , R. A. Gruendl , I. Harrison , W. G. Hartley , K. Herner , H. Huang , E. M. Huff , M. Jarvis , E. Krause , N. Kuropatkin , P. -F. Leget , N. MacCrann , J. McCullough , A. Navarro-Alsina , S. Pandey , J. Prat , M. Raveri , R. P. Rollins , A. Roodman , R. Rosenfeld , A. J. Ross , E. S. Rykoff , J. Sanchez , L. F. Secco , I. Sevilla-Noarbe , E. Sheldon , T. Shin , M. A. Troxel , I. Tutusaus , T. N. Varga , R. H. Wechsler , B. Yanny , Y. Zhang , J. Zuntz , M. Aguena , J. Annis , D. Bacon , S. Bocquet , D. Brooks , D. L. Burke , J. Carretero , F. J. Castander , M. Costanzi , L. N. da Costa , J. De Vicente , P. Doel , I. Ferrero , B. Flaugher , J. Frieman , J. García-Bellido , E. Gaztanaga , G. Gutierrez , S. R. Hinton , D. L. Hollowood , K. Honscheid , D. J. James , K. Kuehn , M. Lima , H. Lin , J. L. Marshall , J. Mena-Fernández , F. Menanteau , R. Miquel , R. L. C. Ogando , M. Paterno , M. E. S. Pereira , A. Pieres , A. A. Plazas Malagón , A. Porredon , E. Sanchez , D. Sanchez Cid , M. Smith , E. Suchyta , M. E. C. Swanson , G. Tarle , C. To , V. Vikram , N. Weaverdyck

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

Nowadays, with the advance of technology, there is an increasing amount of unstructured data being generated every day. However, it is a painful job to label and organize it. Labeling is an expensive, time-consuming, and difficult task. It…

Machine Learning · Computer Science 2020-06-25 Pedro H. M. Braga , Heitor R. Medeiros , Hansenclever F. Bassani

Accurate estimation of photometric redshifts (photo-$z$s) is crucial for cosmological surveys. Various methods have been developed for this purpose, such as template fitting methods and machine learning techniques, each with its own…

The growing volume of data produced by large astronomical surveys necessitates the development of efficient analysis techniques capable of effectively managing high-dimensional datasets. This study addresses this need by demonstrating some…

We develop a novel method to explore the galaxy-halo connection using the galaxy imaging surveys by modeling the projected two-point correlation function measured from the galaxies with reasonable photometric redshift measurements. By…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-17 Zhaoyu Wang , Haojie Xu , Xiaohu Yang , Y. P. Jing , Hong Guo , Zheng Zheng , Ying Zu , Zhigang Li , Chengze Liu

Galaxy cross-correlations with high-fidelity redshift samples hold the potential to precisely calibrate systematic photometric redshift uncertainties arising from the unavailability of complete and representative training and validation…

We present a new method for inferring photometric redshifts in deep galaxy and quasar surveys, based on a data driven model of latent spectral energy distributions (SEDs) and a physical model of photometric fluxes as a function of redshift.…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-29 Boris Leistedt , David W. Hogg

Parameter prediction is essential for many applications, facilitating insightful interpretation and decision-making. However, in many real life domains, such as power systems, medicine, and engineering, it can be very expensive to acquire…

Machine Learning · Computer Science 2024-02-16 Zimeng Lyu , Alexander Ororbia , Rui Li , Travis Desell

This paper demonstrates a novel and efficient unsupervised clustering method with the combination of a Self-Organising Map (SOM) and a convolutional autoencoder. The rapidly increasing volume of radio-astronomical data has increased demand…

The calibration of redshift distributions for photometric samples using spectroscopic surveys is plagued by the difficulty in modelling the selection functions of spectroscopic surveys. In this work, we analyse how these selection functions…

Instrumentation and Methods for Astrophysics · Physics 2022-07-19 Isaac McMahon , Markus Michael Rau , Rachel Mandelbaum

In the next decade, the LSST will become a major facility for the astronomical community. However accurately determining the redshifts of the observed galaxies without using spectroscopy is a major challenge. Reconstruction of the redshifts…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Alexia Gorecki , Alexandra Abate , Réza Ansari , Aurélien Barrau , Sylvain Baumont , Marc Moniez , Jean-Stéphane Ricol

Accurate redshift estimates are a vital component in understanding galaxy evolution and precision cosmology. In this paper, we explore approaches to increase the applicability of machine learning models for photometric redshift estimation…

Instrumentation and Methods for Astrophysics · Physics 2026-01-27 Jonathan Soriano , Tuan Do , Srinath Saikrishnan , Vikram Seenivasan , Bernie Boscoe , Jack Singal , Evan Jones

We calculate photometric redshifts from the Sloan Digital Sky Survey Main Galaxy Sample, The Galaxy Evolution Explorer All Sky Survey, and The Two Micron All Sky Survey using two new training-set methods. We utilize the broad-band…

Astrophysics · Physics 2008-11-26 M. J. Way , A. N. Srivastava

Accurate photometric redshifts are among the key requirements for precision weak lensing measurements. Both the large size of the Sloan Digital Sky Survey (SDSS) and the existence of large spectroscopic redshift samples that are…