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相关论文: Estimating Galaxy Redshift in Radio-Selected Datas…

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We present a new method to estimate redshift distributions and galaxy-dark matter bias parameters using correlation functions in a fully data driven and self-consistent manner. Unlike other machine learning, template, or correlation…

宇宙学与河外天体物理 · 物理学 2019-09-09 Ben Hoyle , Markus Michael Rau

Determining the redshift distribution $n(z)$ of galaxy samples is essential for several cosmological probes including weak lensing. For imaging surveys, this is usually done using photometric redshifts estimated on an object-by-object…

宇宙学与河外天体物理 · 物理学 2017-08-31 Jörg Herbel , Tomasz Kacprzak , Adam Amara , Alexandre Refregier , Claudio Bruderer , Andrina Nicola

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),…

宇宙学与河外天体物理 · 物理学 2015-05-30 Erin S. Sheldon , Carlos Cunha , Rachel Mandelbaum , J. Brinkmann , Benjamin A. Weaver

We present a dataset built for machine learning applications consisting of galaxy photometry, images, spectroscopic redshifts, and structural properties. This dataset comprises 286,401 galaxy images and photometry from the Hyper-Suprime-Cam…

宇宙学与河外天体物理 · 物理学 2024-10-02 Tuan Do , Bernie Boscoe , Evan Jones , Yun Qi Li , Kevin Alfaro

We use the overlap between multiband photometry of the Kilo-Degree Survey (KiDS) and spectroscopic data based on the Sloan Digital Sky Survey (SDSS) and Galaxy And Mass Assembly (GAMA) to infer the colour-magnitude relation of red-sequence…

In order to retrieve cosmological parameters from photometric surveys, we need to estimate the distribution of the photometric redshift in the sky with excellent accuracy. We use and apply three different machine learning methods to…

宇宙学与河外天体物理 · 物理学 2025-11-13 Elcio Abdalla , Filipe B. Abdalla , Alessandro Marins , Amilcar Queiroz , Rafael M. Ribeiro , Alex S. C. Souza

The aim of this paper is to investigate ways to optimize the accuracy of photometric redshifts for a SNAP like mission. We focus on how the accuracy of the photometric redshifts depends on the magnitude limit and signal-to-noise ratio,…

We use redshift determinations and spectral analysis of galaxies in the 2dF Galaxy Redshift Survey to study the properties of local radio sources with $S\ge 1$ mJy. 557 objects drawn from the FIRST survey, corresponding to 2.3 per cent of…

This is the second in a series of papers presenting observations and results for a sample of 76 ultra-steep-spectrum (USS) radio sources in the southern hemisphere designed to find galaxies at high redshift. Here we focus on the optical…

Aims. We explore machine learning techniques to forecast star formation rate, stellar mass, and metallicity across galaxies with redshifts ranging from 0.01 to 0.3. Methods. Leveraging CatBoost and deep learning architectures, we utilize…

星系天体物理 · 物理学 2024-05-27 F. Z. Zeraatgari , F. Hafezianzadeh , Y. -X. Zhang , A. Mosallanezhad , J. -Y. Zhang

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

Observationally, weak lensing has been served so far by optical surveys due to the much larger number densities of background galaxies achieved, which is typically by two to three orders of magnitude compared to radio. However, the high…

天体物理仪器与方法 · 物理学 2016-03-18 Marzia Rivi , Lance Miller , Sphesihle Makhathini , Filipe Batoni Abdalla

For many machine learning algorithms such as $k$-Nearest Neighbor ($k$-NN) classifiers and $ k $-means clustering, often their success heavily depends on the metric used to calculate distances between different data points. An effective…

计算机视觉与模式识别 · 计算机科学 2010-03-03 Chunhua Shen , Junae Kim , Lei Wang

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…

天体物理学 · 物理学 2010-03-18 Carlos E. Cunha , Marcos Lima , Hiroaki Oyaizu , Joshua Frieman , Huan Lin

Over the next few years new spectroscopic surveys (from the optical surveys of the Sloan Digital Sky Survey and the 2 degree Field survey through to space-based ultraviolet satellites such as GALEX) will provide the opportunity and…

天体物理学 · 物理学 2009-10-31 A. J. Connolly , A. S. Szalay

Wide-field slitless spectroscopic galaxy surveys, such as the one performed by the upcoming Chinese Space Station Survey Telescope (CSST), are crucial for precision cosmology but present formidable data analysis challenges. Because spectra…

天体物理仪器与方法 · 物理学 2026-05-19 Xingchen Zhou , Yan Gong , Xin Zhang , Xian-Min Meng , Haitao Miao , Run Wen , Nan Li

We use multi-band optical and near-infrared photometric observations of galaxies in the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS) to predict photometric redshifts using artificial neural networks. The…

星系天体物理 · 物理学 2020-01-15 Derek Wilson , Hooshang Nayyeri , Asantha Cooray , Boris Häußler

We present a comparison between the published optical, IR and CO spectroscopic redshifts of 86 (sub-)mm galaxies and their photometric redshifts as derived from long-wavelength radio-mm-FIR photometric data. The redshift accuracy measured…

天体物理学 · 物理学 2007-05-23 Itziar Aretxaga , David H. Hughes , James S. Dunlop

This paper explores the application of machine learning methods for classifying astronomical sources using photometric data, including normal and emission line galaxies (ELGs; starforming, starburst, AGN, broad line), quasars, and stars. We…

We present a new training set for estimating empirical photometric redshifts of galaxies, which was created as part of the 2dFLenS project. This training set is located in a 700 sq deg area of the KiDS South field and is randomly selected…