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Related papers: Photo-$z$ Estimation with Normalizing Flow

200 papers

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

In the present study, we use the DES Y3 catalog of LRG to incorporate the realistic galaxies' redshift Probability Distribution Function(PDF) into the correlation function cosmological model. We used four different photo-z estimators ANNz2,…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-06 Paula S. Ferreira , Ribamar R. R. Reis

Normalizing flows (NFs) provide exact likelihoods and deterministic invertible sampling, but have historically lagged behind diffusion models for large-scale image generation. We identify a key obstacle: NFs are required to learn a single…

Computer Vision and Pattern Recognition · Computer Science 2026-05-26 Longtao Jiang , Jianmin Bao , Zhendong Wang , Xin Tao , Pengfei Wan , Zhihui Li , Xiaojun Chang

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

Modeling and synthesizing image noise is an important aspect in many computer vision applications. The long-standing additive white Gaussian and heteroscedastic (signal-dependent) noise models widely used in the literature provide only a…

Computer Vision and Pattern Recognition · Computer Science 2019-08-23 Abdelrahman Abdelhamed , Marcus A. Brubaker , Michael S. Brown

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

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

Accurate and precise photometric redshifts (photo-z's) of Type Ia supernovae (SNe Ia) can enable the use of SNe Ia, measured only with photometry, to probe cosmology. This dramatically increases the science return of supernova surveys…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Yun Wang , E. Gjergo , S. Kuhlmann

Large imaging surveys will rely on photometric redshifts (photo-z's), which are typically estimated through machine learning methods. Currently planned spectroscopic surveys will not be deep enough to produce a representative training…

The Chinese Space Station Optical Survey (CSS-OS) is a major science project of the Space Application System of the China Manned Space Program. This survey is planned to perform both photometric imaging and slitless spectroscopic…

Instrumentation and Methods for Astrophysics · Physics 2018-08-23 Ye Cao , Yan Gong , Xian-Min Meng , Cong K. Xu , Xuelei Chen , Qi Guo , Ran Li , Dezi Liu , Yongquan Xue , Li Cao , Xiyang Fu , Xin Zhang , Shen Wang , Hu Zhan

Many scientific investigations of photometric galaxy surveys require redshift estimates, whose uncertainty properties are best encapsulated by photometric redshift (photo-z) posterior probability density functions (PDFs). A plethora of…

Accurate redshift calibration is required to obtain unbiased cosmological information from large-scale galaxy surveys. In a forward modelling approach, the redshift distribution n(z) of a galaxy sample is measured using a parametric galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-13 Beatrice Moser , Tomasz Kacprzak , Silvan Fischbacher , Alexandre Refregier , Dominic Grimm , Luca Tortorelli

We present the first systematic analysis of photometric redshifts (photo-z) estimated from the Rubin Observatory Data Preview 1 (DP1) data taken with the Legacy Survey of Space and Time (LSST) Commissioning Camera. Employing the Redshift…

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

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

The need for accurate photometric redshifts estimation is a topic that has fundamental importance in Astronomy, due to the necessity of efficiently obtaining redshift information without the need of spectroscopic analysis. We propose a…

Instrumentation and Methods for Astrophysics · Physics 2017-06-14 Antonio D'Isanto

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

Obtaining accurately calibrated redshift distributions of photometric samples is one of the great challenges in photometric surveys like LSST, Euclid, HSC, KiDS, and DES. We present an inference methodology that combines the redshift…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-09 M. M. Rau , C. B. Morrison , S. J. Schmidt , S. Wilson , R. Mandelbaum , Y. Y. Mao

To address the challenge of estimating redshifts when only single-band images are available, this study introduces a deep learning model named ViT-MDNz. Leveraging robust statistical priors learned from large-scale data concerning the…

Astrophysics of Galaxies · Physics 2026-02-27 Zhijian Luo , Yangyang Li , Jianzhen Chen , Qishen Cao , Duo Cao , Shaohua Zhang , Hubing Xiao , Chenggang Shu

In this work, we explore methods to improve galaxy redshift predictions by combining different ground truths. Traditional machine learning models rely on training sets with known spectroscopic redshifts, which are precise but only represent…

Instrumentation and Methods for Astrophysics · Physics 2024-11-28 Jonathan Soriano , Srinath Saikrishnan , Vikram Seenivasan , Bernie Boscoe , Jack Singal , Tuan Do