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Related papers: Classification and Redshift Estimation in Multi-Co…

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Redshift measures the distance to galaxies and underlies our understanding of the origin of the Universe and galaxy evolution. Spectroscopic redshift is the gold-standard method for measuring redshift, but it requires about $1000$ times…

Astrophysics of Galaxies · Physics 2025-05-19 Andrew Lizarraga , Eric Hanchen Jiang , Jacob Nowack , Yun Qi Li , Ying Nian Wu , Bernie Boscoe , Tuan Do

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

In an investigation of the cause of the cosmic microwave background decrement in the field of the z = 3.8 quasar pair PC1643+4631, we have carried out a study to photometrically estimate the redshifts of galaxies in deep multi-colour…

Astrophysics · Physics 2009-10-31 Garret Cotter , Toby Haynes , Joanne C. Baker , Michael E. Jones , Richard Saunders

We investigate the expected accuracy of redshifts that can be obtained using low-resolution spectroscopic (medium-band) data from the 7-Dimensional Sky Survey (7DS). By leveraging 40 densely sampled filters with widths of full width at half…

Astrophysics of Galaxies · Physics 2025-10-01 Eunhee Ko , Myungshin Im , Yujin Yang , Ji Hoon Kim , Seong-Kook Lee , Gregory S. -H. Paek

This paper describes the methodology currently being implemented in the EIS pipeline for analysing optical/infrared multi-colour data. The aim is to identify different classes of objects as well as possible undesirable features associated…

The 2dF Galaxy Redshift Survey (2dFGRS) is designed to measure redshifts for approximately 250000 galaxies. This paper describes the survey design, the spectroscopic observations, the redshift measurements and the survey database. The…

We present an empirical method for estimating the underlying redshift distribution N(z) of galaxy photometric samples from photometric observables. The method does not rely on photometric redshift (photo-z) estimates for individual…

Astrophysics · Physics 2008-11-26 Marcos Lima , Carlos E. Cunha , Hiroaki Oyaizu , Joshua Frieman , Huan Lin , Erin S. Sheldon

We present simulations of quasar colors, magnitudes, and numbers at redshifts 5<z<10 based on our discovery of ten new high-redshift quasars and the cloning of lower redshift Sloan Digital Sky Survey (SDSS) quasars. The ten quasars have…

We present a new algorithm, CAMIRA, to identify clusters of galaxies in wide-field imaging survey data. We base our algorithm on the stellar population synthesis model to predict colours of red-sequence galaxies at a given redshift for an…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Masamune Oguri

The results of a large area, ~600 deg^2, K-band flux-limited spectroscopic survey for luminous quasars are presented. The survey utilises the UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS) in regions of sky within the Sloan…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Natasha Maddox , Paul C. Hewett , Celine Peroux , Daniel B. Nestor , Lutz Wisotzki

We apply one of lazy learning methods named k-nearest neighbor algorithm (kNN) to estimate the photometric redshifts of quasars, based on various datasets from the Sloan Digital Sky Survey (SDSS), UKIRT Infrared Deep Sky Survey (UKIDSS) and…

Instrumentation and Methods for Astrophysics · Physics 2017-03-22 Zhang Yanxia , Ma He , Peng Nanbo , Zhao Yongheng , Wu Xue-bing

We present the COSMOS2015 catalog which contains precise photometric redshifts and stellar masses for more than half a million objects over the 2deg$^{2}$ COSMOS field. Including new $YJHK_{\rm s}$ images from the UltraVISTA-DR2 survey,…

We present first results on the use of a colour space filter for detecting galaxy clusters at cosmological redshifts in the XMM Large Scale Structure Survey. All clusters studied, but one, are successfully colour--detected in spite of their…

Astrophysics · Physics 2007-05-23 S. Andreon , J. Willis , H. Quintana , I. Valtchanov , M. Pierre , F. Pacaud

Six objects with broad emission lines and redshifts from 0.48 to 2.07 were discovered among 736 extragalactic objects in the Canada-France Redshift Survey (CFRS). Although the luminosities of half of the objects are such that they are in…

Astrophysics · Physics 2015-06-24 David Schade , David Crampton , F. Hammer , O. Le Fevre , S. J. Lilly

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…

Astrophysics · Physics 2007-05-23 Itziar Aretxaga , David H. Hughes , James S. Dunlop

Photometric redshift (photo-z) is a fundamental parameter for multi-wavelength photometric surveys, while galaxy clusters are important cosmological probers and ideal objects for exploring the dense environmental impact on galaxy evolution.…

Astrophysics of Galaxies · Physics 2022-06-01 Hu Zou , Jipeng Sui , Suijian Xue , Xu Zhou , Jun Ma , Zhimin Zhou , Jundan Nie , Tianmeng Zhang , Lu Feng , Zhixia Shen , Jiali Wang

The development of fast and accurate methods of photometric redshift estimation is a vital step towards being able to fully utilize the data of next-generation surveys within precision cosmology. In this paper we apply a specific approach…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 P. E. Freeman , J. A. Newman , A. B. Lee , J. W. Richards , C. M. Schafer

In the next years, several cosmological surveys will rely on imaging data to estimate the redshift of galaxies, using traditional filter systems with 4-5 optical broad bands; narrower filters improve the spectral resolution, but strongly…

Accurately characterizing the redshift distributions of galaxies is essential for analysing deep photometric surveys and testing cosmological models. We present a technique to simultaneously infer redshift distributions and individual…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-27 Boris Leistedt , Daniel J. Mortlock , Hiranya V. Peiris