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We present a star/galaxy classification for the Southern Photometric Local Universe Survey (S-PLUS), based on a Machine Learning approach: the Random Forest algorithm. We train the algorithm using the S-PLUS optical photometry up to $r$=21,…

This paper evaluates XGboost's performance given different dataset sizes and class distributions, from perfectly balanced to highly imbalanced. XGBoost has been selected for evaluation, as it stands out in several benchmarks due to its…

Machine Learning · Computer Science 2023-03-28 Gissel Velarde , Anindya Sudhir , Sanjay Deshmane , Anuj Deshmunkh , Khushboo Sharma , Vaibhav Joshi

We present results of using individual galaxies' redshift probability information derived from a photometric redshift (photo-z) algorithm, SPIDERz, to identify potential catastrophic outliers in photometric redshift determinations. By using…

Astrophysics of Galaxies · Physics 2019-11-07 Evan Jones , J. Singal

The Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) will produce several billion photometric redshifts (photo-$z$'s), enabling cosmological analyses to select a subset of galaxies with the most accurate photo-$z$. We…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-08 Adam Broussard , Eric Gawiser

Galaxy morphologies provide valuable insights into their formation processes, tracing the spatial distribution of ongoing star formation and encoding signatures of dynamical interactions. While such information has been extensively…

(abridged) Mass loss is a key parameter in the evolution of massive stars, with discrepancies between theory and observations and with unknown importance of the episodic mass loss. To address this we need increased numbers of classified…

Solar and Stellar Astrophysics · Physics 2022-10-19 Grigoris Maravelias , Alceste Z. Bonanos , Frank Tramper , Stephan de Wit , Ming Yang , Paolo Bonfini

We present a spectroscopic redshift catalog from the LAMOST Complete Spectroscopic Survey of Pointing Area (LaCoSSPAr) in the Southern Galactic Cap (SGC), which is designed to observe all sources (Galactic and extra-galactic) by using…

The next generation of proposed galaxy surveys will increase the number of galaxies with photometric redshifts by two orders of magnitude, drastically expanding both redshift range and detection threshold from the current state of the art.…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 A. E. Schulz

Classification will be an important first step for upcoming surveys that will detect billions of new sources such as LSST and Euclid, as well as DESI, 4MOST and MOONS. The application of traditional methods of model fitting and…

Astrophysics of Galaxies · Physics 2020-01-29 Crispin Logan , Sotiria Fotopoulou

The calibration of redshift distributions for photometric samples using spectroscopic surveys is plagued by the difficulty in modelling the selection functions of spectroscopic surveys. In this work, we analyse how these selection functions…

Instrumentation and Methods for Astrophysics · Physics 2022-07-19 Isaac McMahon , Markus Michael Rau , Rachel Mandelbaum

We present photometric redshifts and associated probability distributions for all detected sources in the Extended Chandra Deep Field South (ECDFS). The work makes use of the most up-to-date data from the Cosmic Assembly Near-IR Deep Legacy…

Calibrating the photometric redshifts of >10^9 galaxies for upcoming weak lensing cosmology experiments is a major challenge for the astrophysics community. The path to obtaining the required spectroscopic redshifts for training and…

We present the SWIRE Photometric Redshift Catalogue, 1025119 redshifts of unprecedented reliability and accuracy. Our method is based on fixed galaxy and QSO templates applied to data at 0.36-4.5 mu, and on a set of 4 infrared emission…

(abridged) We present a new sample of X-ray selected galaxy groups and clusters serendipitously observed with Swift and the X-ray Telescope (XRT). We searched the XRT archive for extended sources among 336 GRB fields with galactic latitude…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-15 Elena Tundo , Alberto Moretti , Paolo Tozzi , Liu Teng , Piero Rosati , Gianpiero Tagliaferri , Sergio Campana

We introduce a novel galaxy classification methodology based on the visible spectra of a sample of over 68,000 nearby ($z\leq 0.1$) Sloan Digital Sky Survey lenticular (S0) galaxies. Unlike traditional diagnostic diagrams, which rely on a…

Astrophysics of Galaxies · Physics 2025-01-10 J. L. Tous , J. M. Solanes , J. D. Perea

We evaluate the performance of the SDSS DR8 redMaPPer photometric cluster catalog by comparing it to overlapping X-ray and SZ selected catalogs from the literature. We confirm the redMaPPer photometric redshifts are nearly unbiased (<\Delta…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Eduardo Rozo , Eli S. Rykoff

The Red-Sequence Cluster Survey (RCS) provides a large and deep photometric catalog of galaxies in the $z'$ and $R_c$ bands for ~90 square degrees of sky, and supplemental $V$ and $B$ data have been obtained for 33.6 deg$^{2}$. We compile a…

Astrophysics · Physics 2009-11-10 B. C. Hsieh , H. K. C. Yee , H. Lin , M. D. Gladders

Redshift is a key quantity for inferring cosmological model parameters. In photometric redshift estimation, cosmologists use the coarse data collected from the vast majority of galaxies to predict the redshift of individual galaxies. To…

Applications · Statistics 2016-04-07 Rafael Izbicki , Ann B. Lee , Peter E. Freeman

Stage IV cosmological surveys will map the universe with unprecedented precision, reducing statistical uncertainties to levels where unmodelled systematics can significantly bias inference. In particular, photometric redshift (photo-z)…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-11 Carolyn McDonald Mill , C. Danielle Leonard , Markus Michael Rau , Cora Uhlemann , Shahab Joudaki

We present a catalog of quasars and corresponding redshifts in the Kilo-Degree Survey (KiDS) Data Release 4. We trained machine learning (ML) models, using optical ugri and near-infrared ZYJHK_s bands, on objects known from Sloan Digital…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-19 S. J. Nakoneczny , M. Bilicki , A. Pollo , M. Asgari , A. Dvornik , T. Erben , B. Giblin , C. Heymans , H. Hildebrandt , A. Kannawadi , K. Kuijken , N. R. Napolitano , E. Valentijn
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