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We use extensive multi-wavelength photometric data from the Great Observatories Origins Deep Survey (GOODS) to estimate photometric redshifts for a sample of 434 galaxies with spectroscopic redshifts in the Chandra Deep Field South. Using…

(Abridged) In this paper we present photometric redshift estimates for a sample of X-ray selected sources detected in the wide field (~2 deg^2), bright [f_{X} (0.5-8 keV)~10^{-14} cgs] XMM-Newton/2dF survey. Unlike deeper X-ray samples…

天体物理学 · 物理学 2008-11-26 S. Kitsionas , E. Hatziminaoglou , A. Georgakakis , I. Georgantopoulos

The Southern Photometric Local Universe Survey (S-PLUS) is a novel project that aims to map the Southern Hemisphere using a twelve filter system, comprising five broad-band SDSS-like filters and seven narrow-band filters optimized for…

We use the deepest and the most comprehensive photometric data currently available for GOODS-South galaxies to measure their photometric redshifts. The photometry includes VLT/VIMOS (U-band), HST/ACS (F435W, F606W, F775W, and F850LP bands),…

In this paper we study the accuracy of photometric redshifts computed through a standard SED fitting procedure, where SEDs are obtained from broad-band photometry. We present our public code hyperz, which is presently available on the web.…

天体物理学 · 物理学 2007-05-23 Micol Bolzonella , Joan-Marc Miralles , Roser Pello'

In this paper we present and characterize a nearest-neighbors color-matching photometric redshift estimator that features a direct relationship between the precision and accuracy of the input magnitudes and the output photometric redshifts.…

In order to answer the open questions of modern cosmology and galaxy evolution theory, robust algorithms for calculating photometric redshifts (photo-z) for very large samples of galaxies are needed. Correct estimation of the various…

天体物理仪器与方法 · 物理学 2021-08-25 Oleksandra Razim , Stefano Cavuoti , Massimo Brescia , Giuseppe Riccio , Mara Salvato , Giuseppe Longo

We exploit the synergy between low-resolution spectroscopy and photometric redshifts to study environmental effects on galaxy evolution in slitless spectroscopic surveys from space. As a test case, we consider the future Euclid Deep survey…

星系天体物理 · 物理学 2016-08-31 O. Cucciati , F. Marulli , A. Cimatti , A. I. Merson , P. Norberg , L. Pozzetti , C. M. Baugh , E. Branchini

Noisy distance estimates associated with photometric rather than spectroscopic redshifts lead to a mis-estimate of the luminosities, and produce a correlated mis-estimate of the sizes. We consider a sample of early-type galaxies from the…

宇宙学与河外天体物理 · 物理学 2015-05-13 Graziano Rossi , Ravi K. Sheth , Changbom Park

In this work I discuss the necessary steps for deriving photometric redshifts for luminous red galaxies (LRGs) and galaxy clusters through simple empirical methods. The data used is from the Sloan Digital Sky Survey (SDSS). I show that with…

天体物理学 · 物理学 2009-02-10 P. A. A. Lopes

In the era of large sky surveys, photometric redshifts (photo-z) represent crucial information for galaxy evolution and cosmology studies. In this work, we propose a new Machine Learning (ML) tool called Galaxy morphoto-Z with neural…

Obtaining well-calibrated photometric redshift probability densities for galaxies without a spectroscopic measurement remains a challenge. Deep learning discriminative models, typically fed with multi-band galaxy images, can produce outputs…

Accurate weak lensing mass estimates of clusters are needed in order to calibrate mass proxies for the cosmological exploitation of galaxy cluster surveys. Such measurements require accurate knowledge of the redshift distribution of the…

星系天体物理 · 物理学 2020-07-15 S. F. Raihan , T. Schrabback , H. Hildebrandt , D. Applegate , G. Mahler

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…

As a consequence of galaxy clustering, close galaxies observed on the plane of the sky should be spatially correlated with a probability that is inversely proportional to their angular separation. In principle, this information can be used…

宇宙学与河外天体物理 · 物理学 2023-04-19 F. Tosone , M. S. Cagliari , L. Guzzo , B. R. Granett , A. Crespi

Given multiband photometric data from the SDSS DR6, we estimate galaxy redshifts. We employ a Random Forest trained on color features and spectroscopic redshifts from 80,000 randomly chosen primary galaxies yielding a mapping from color to…

天体物理学 · 物理学 2007-11-16 Samuel Carliles , Tamás Budavári , Sebastien Heinis , Carey Priebe , Alexander Szalay

The Physics of the Accelerating Universe (PAU) survey at the William Herschel Telescope (WHT) will use a new optical camera (PAUCam) with a large set of narrow-band filters to perform a photometric galaxy survey with a quasi-spectroscopic…

宇宙学与河外天体物理 · 物理学 2014-06-06 Pol Martí , Ramon Miquel , Francisco J. Castander , Enrique Gaztañaga , Martin Eriksen , Carles Sánchez

Estimating redshifts from broadband photometry is often limited by how accurately we can map the colors of galaxies to an underlying spectral template. Current techniques utilize spectrophotometric samples of galaxies or spectra derived…

天体物理仪器与方法 · 物理学 2025-03-11 John Franklin Crenshaw , Andrew J. Connolly

Deep Learning models have been increasingly exploited in astrophysical studies, yet such data-driven algorithms are prone to producing biased outputs detrimental for subsequent analyses. In this work, we investigate two major forms of…

天体物理仪器与方法 · 物理学 2022-06-15 Q. Lin , D. Fouchez , J. Pasquet , M. Treyer , R. Ait Ouahmed , S. Arnouts , O. Ilbert

We present a new catalog of high-redshift candidate \textit{Herschel} sources. Our sample is obtained after applying a multifrequency filtering method ("matched multifilter"), which is designed to improve the signal-to-noise ratio (S/N) of…

星系天体物理 · 物理学 2019-02-06 A. Manjón-García , D. Herranz , J. M. Diego , L. Bonavera , J. González-Nuevo