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Related papers: 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…

Cosmology and Nongalactic Astrophysics · Physics 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…

Instrumentation and Methods for Astrophysics · Physics 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…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-10 Christopher B. Morrison , Hendrik Hildebrandt , Samuel J. Schmidt , Ivan K. Baldry , Maciej Bilicki , Ami Choi , Thomas Erben , Peter Schneider

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…

Cosmology and Nongalactic Astrophysics · Physics 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…

Cosmology and Nongalactic Astrophysics · Physics 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…

Instrumentation and Methods for Astrophysics · Physics 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…

Cosmology and Nongalactic Astrophysics · Physics 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…

Cosmology and Nongalactic Astrophysics · Physics 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…

Astrophysics of Galaxies · Physics 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…

Astrophysics · Physics 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…

Instrumentation and Methods for Astrophysics · Physics 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…

Astrophysics of Galaxies · Physics 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…

Astrophysics of Galaxies · Physics 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…

Instrumentation and Methods for Astrophysics · Physics 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…

Methodology · Statistics 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…

Astrophysics of Galaxies · Physics 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…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 A. Amara , A. Refregier , S. Paulin-Henriksson