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相关论文: Photometric redshifts and K-corrections for Sloan …

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We investigate two training-set methods: support vector machines (SVMs) and Kernel Regression (KR) for photometric redshift estimation with the data from the Sloan Digital Sky Survey Data Release 5 and Two Micron All Sky Survey databases.…

天体物理学 · 物理学 2009-11-13 Dan Wang , Yan-Xia Zhang , Chao Liu , Yong-Heng Zhao

This paper presents a comprehensive study of quasar photometric classification and redshift estimation using machine learning techniques. We cross-matched photometric data from the Dark Energy Survey Data Release 2 (DES DR2) with…

天体物理仪器与方法 · 物理学 2026-05-19 Pablo Motta , Filipe B. Abdalla , Elcio Abdalla , Gabriel S. Costa , Camila Cardoso

A method of obtaining approximate redshifts and spectral types of galaxies using a photometric system of six broad-bandpass filters is developed. The technique utilizes a smallest maximum difference approach rather than a least-squares…

天体物理学 · 物理学 2009-10-30 Charles T. Liu , Richard F. Green

We re-examine the technique of determining the redshifts of galaxies from the ratio of the submillimeter-to-radio continuum flux densities based on a recently published catalog of 850~$\mu$m sources. We derived the expected variation of…

天体物理学 · 物理学 2015-06-24 T. N. Rengarajan , Tsutomu T. Takeuchi

Many of the cosmological tests to be performed by planned dark energy experiments will require extremely well-characterized photometric redshift measurements. Current estimates are that the true mean redshift of the objects in each photo-z…

宇宙学与河外天体物理 · 物理学 2010-11-22 Daniel J. Matthews , Jeffrey A. Newman

A new method is developed for estimating photometric redshifts to galaxies, using realistic template SEDs, extending over four decades in wavelength (i.e. from 0.05 micron to 1 mm). The template SEDs are constructed for four different…

天体物理学 · 物理学 2007-05-23 Bahram Mobasher , Paola Mazzei

We present a recalibration of the Sloan Digital Sky Survey (SDSS) photometry with new flat fields and zero points derived from Pan-STARRS1 (PS1). Using PSF photometry of 60 million stars with $16 < r < 20$, we derive a model of amplifier…

We construct new galaxy angular power spectra based on the extended, updated and final SDSS II Luminous Red Galaxy (LRG) photometric redshift survey: MegaZ DR7. Encapsulating 7746 deg^{2} we utilise 723,556 photometrically determined LRGs…

宇宙学与河外天体物理 · 物理学 2016-05-25 Shaun A. Thomas , Filipe B. Abdalla , Ofer Lahav

Using the newly available infrared images of the Hubble Deep Field in the J, H, and K bands and an optimal photometric method, we have refined a technique to estimate the redshifts of 1067 galaxies. A detailed comparison of our results with…

天体物理学 · 物理学 2009-10-30 A. Fernandez-Soto , K. M. Lanzetta , A. Yahil

Recent large-scale galaxy spectroscopic surveys, such as the Sloan Digital Sky Survey (SDSS), enable us to execute a systematic, relatively-unbiased search for galaxy clusters. Such surveys make it possible to measure the 3-d distribution…

天体物理学 · 物理学 2009-11-13 Joo H. Yoon , Kevin Schawinski , Yun-Kyeong Sheen , Chang H. Ree , Sukyoung K. Yi

We measure the redshift-dependent luminosity function and the comoving radial density of galaxies in the Sloan Digital Sky Survey Data Release 1 (SDSS DR1). Both measurements indicate that the apparent number density of bright galaxies…

天体物理学 · 物理学 2009-11-10 Jon Loveday

Based on magnitudes and Petrosian radii from the Sloan Digital Sky Survey (SDSS, data release 7) at low redhift (z <0.2), we developed a test of galaxy-size evolution. For this first quantitative size analysis using SDSS data, several…

综合物理 · 物理学 2015-03-17 Alexander Unzicker , Karl Fabian

Three-dimensional wide-field galaxy surveys are fundamental for cosmological studies. For higher redshifts (z > 1.0), where galaxies are too faint, quasars still trace the large-scale structure of the Universe. Since available telescope…

天体物理仪器与方法 · 物理学 2022-09-21 Sándor Kunsági-Máté , Róbert Beck , István Szapudi , István Csabai

We introduce redMaGiC, an automated algorithm for selecting Luminous Red Galaxies (LRGs). The algorithm was specifically developed to minimize photometric redshift uncertainties in photometric large-scale structure studies. redMaGiC…

We report new improved photometric redshifts of 1048 galaxies in the Hubble Deep Field (HDF). A standard chi^2 minimizing method is applied to seven-color UBVIJHK photometry by Fernandez-Soto, Lanzetta, & Yahil (1999). We use 187 template…

天体物理学 · 物理学 2009-10-31 Hisanori Furusawa , Kazuhiro Shimasaku , Mamoru Doi , Sadanori Okamura

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…

天体物理仪器与方法 · 物理学 2017-03-22 Zhang Yanxia , Ma He , Peng Nanbo , Zhao Yongheng , Wu Xue-bing

We present improved methods for using stars found in astronomical exposures to calibrate both star and galaxy colors as well as to adjust the instrument flat field. By developing a spectroscopic model for the SDSS stellar locus in…

We present the first results from the Faint Infra-Red Extragalactic Survey (FIRES) of the Hubble Deep Field South. Using a combination of deep near infrared data obtained with ISAAC at the VLT with the WFPC2 HST data, we construct a K-band…

We present photometric redshifts and spectral energy distribution (SED) classifications for a sample of 1542 optically identified sources detected with XMM in the COSMOS field. Our template fitting classifies 46 sources as stars and 464 as…