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相关论文: Spectroscopic QUasar Extractor and redshift (z) Es…

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We simulate galaxy properties and redshift estimation for SPHEREx, the next NASA Medium Class Explorer. To make robust models of the galaxy population and test spectro-photometric redshift performance for SPHEREx, we develop a set of…

宇宙学与河外天体物理 · 物理学 2023-12-11 Richard M. Feder , Daniel C. Masters , Bomee Lee , James J. Bock , Yi-Kuan Chiang , Ami Choi , Olivier Dore , Shoubaneh Hemmati , Olivier Ilbert

We introduce QuasarNET, a deep convolutional neural network that performs classification and redshift estimation of astrophysical spectra with human-expert accuracy. We pose these two tasks as a \emph{feature detection} problem: presence or…

天体物理仪器与方法 · 物理学 2018-08-31 Nicolas Busca , Christophe Balland

We present The-wiZZ, an open source and user-friendly software for estimating the redshift distributions of photometric galaxies with unknown redshifts by spatially cross-correlating them against a reference sample with known redshifts. The…

We perform an analysis of photometric redshifts estimated by using a non-representative training sets in magnitude space. We use the ANNz2 and GPz algorithms to estimate the photometric redshift both in simulations as well as in real data…

宇宙学与河外天体物理 · 物理学 2018-04-12 J. D. Rivera , B. Moraes , A. I. Merson , S. Jouvel , F. B. Abdalla , M. C. B Abdalla

An accurate calibration of the source redshift distribution $p(z)$ is a key aspect in the analysis of cosmic shear data. This, one way or another, requires the use of spectroscopic or high-quality photometric samples. However, the…

宇宙学与河外天体物理 · 物理学 2023-01-25 Carlos García-García , David Alonso , Pedro G. Ferreira , Boryana Hadzhiyska , Andrina Nicola , Carles Sánchez , Anže Slosar

This work presents a method for determining the accuracy of a source finder algorithm for spectral line radio astronomy data and the Source Finder Accuracy Evaluator (SFAE), a program that implements this method. The accuracy of a source…

天体物理仪器与方法 · 物理学 2015-06-03 Stefan Westerlund , Christopher Harris , Tobias Westmeier

This paper reports the results obtained on the photometric redshifts measurement and accuracy, and cluster tomography in the ESO Distant Cluster Survey (EDisCS) fields. Photometric redshifts were computed using two independent codes (Hyperz…

This document summarizes the science cases related to cosmology studies with the MaunaKea Spectroscopic Explorer (MSE), a highly-multiplexed (4332 fibers), wide FOV (1.5 sq deg), large aperture (11.25 m in diameter), optical/NIR (360nm to…

BOSS, the Baryon Oscillation Spectroscopic Survey, is a 5-year program to measure the absolute cosmic distance scale and expansion rate with percent-level precision at redshifts z<0.7 and z~2.5. BOSS uses the "standard ruler" provided by…

宇宙学与河外天体物理 · 物理学 2009-02-27 David Schlegel , Martin White , Daniel Eisenstein

The estimation of spectroscopic and photometric redshifts (spec-z and photo-z) is crucial for future cosmological surveys. It can directly affect several powerful measurements of the Universe, e.g. weak lensing and galaxy clustering. In…

宇宙学与河外天体物理 · 物理学 2021-03-05 Xingchen Zhou , Yan Gong , Xian-Min Meng , Xin Zhang , Ye Cao , Xuelei Chen , Valeria Amaro , Zuhui Fan , Liping Fu

We present a photometric redshift (photo-$z$) estimation technique for galaxies in the P\lowercase{an}-STARRS1 (PS1) $3\pi $ survey. Specifically, we train and test a regression and a classification Random-Forest (RF) models using…

星系天体物理 · 物理学 2021-05-28 A. Baldeschi , M. Stroh , R. Margutti , T. Laskar , A. Miller

We present an algorithm for selecting an uniform sample of gravitationally lensed quasar candidates from low-redshift (0.6<z<2.2) quasars brighter than i=19.1 that have been spectroscopically identified in the SDSS. Our algorithm uses…

We show how one may expect a significant number of SZ detections in future Planck data without any of the typical assumptions needed in present component separation methods, such as about the power spectrum or the frequency dependence of…

天体物理学 · 物理学 2009-11-07 J. M. Diego , P. Vielva , E. Martinez-Gonzalez , J. Silk , J. L. Sanz

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

The Pan-STARRS1 (PS1) $3\pi$ survey is a comprehensive optical imaging survey of three quarters of the sky in the $grizy$ broad-band photometric filters. We present the methodology used in assembling the source classification and…

星系天体物理 · 物理学 2020-09-09 Róbert Beck , István Szapudi , Heather Flewelling , Conrad Holmberg , Eugene Magnier

Extremely red quasars (ERQs) are an interesting sample of quasars in the Baryon Oscillation Spectroscopic Sample (BOSS) in the redshift range of $2.0 - 3.4$ and have extreme red colours of $i-W3\ge4.6$. Core ERQs have strong CIV emission…

星系天体物理 · 物理学 2022-02-16 Reza Monadi , Simeon Bird

The process of determining the number and characteristics of sources in astronomical images is so fundamental to a large range of astronomical problems that it is perhaps surprising that no standard procedure has ever been defined that has…

天体物理仪器与方法 · 物理学 2015-06-03 Minh Huynh , Andrew Hopkins , Ray Norris , Paul Hancock , Tara Murphy , Russell Jurek , Matthew Whiting

Qualitative Comparative Analysis (QCA) requires researchers to choose calibration and dichotomization thresholds, and these choices can substantially affect truth tables, minimization, and resulting solution formulas. Despite this…

统计方法学 · 统计学 2026-02-19 Yuki Toyoda

We introduce Z-Sequence, a novel empirical model that utilises photometric measurements of observed galaxies within a specified search radius to estimate the photometric redshift of galaxy clusters. Z-Sequence itself is composed of a…

星系天体物理 · 物理学 2021-04-26 Matthew C. Chan , John P. Stott

Cosmic shear measurements rely on our ability to measure and correct the Point Spread Function (PSF) of the observations. This PSF is measured using stars in the field, which give a noisy measure at random points in the field. Using Wiener…

宇宙学与河外天体物理 · 物理学 2015-05-13 A. Amara , A. Refregier , S. Paulin-Henriksson