English
Related papers

Related papers: QSO Selection Algorithm Using Time Variability and…

200 papers

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…

The EPOCH (EROS-2 periodic variable star classification using machine learning) project aims to detect periodic variable stars in the EROS-2 light curve database. In this paper, we present the first result of the classification of periodic…

Instrumentation and Methods for Astrophysics · Physics 2014-07-02 Dae-Won Kim , Pavlos Protopapas , Coryn A. L. Bailer-Jones , Yong-Ik Byun , Seo-Won Chang , Jean-Baptiste Marquette , Min-Su Shin

Diagnosis results are highly dependent on the volume of test set. To derive the most efficient test set, we propose several machine learning based methods to predict the minimum amount of test data that produces relatively accurate…

Machine Learning · Computer Science 2020-10-30 Kaiming Fu , Yulu Jin , Zhousheng Chen

We present a catalog of 100,563 unresolved, UV-excess (UVX) quasar candidates to g=21 from 2099 deg^2 of the Sloan Digital Sky Survey (SDSS) Data Release One (DR1) imaging data. Existing spectra of 22,737 sources reveals that 22,191 (97.6%)…

The problem of selecting an appropriate number of features in supervised learning problems is investigated in this paper. Starting with common methods in machine learning, we treat the feature selection task as a quadratic unconstrained…

Quantum Physics · Physics 2023-06-21 Gerhard Hellstern , Vanessa Dehn , Martin Zaefferer

We present a new non-parametric method to quantify morphologies of galaxies based on a particular family of learning machines called support vector machines. The method, that can be seen as a generalization of the classical CAS…

Astrophysics · Physics 2009-11-13 M. Huertas-Company , D. Rouan , L. Tasca , G. Soucail , O. Le Fevre

In variable or graph selection problems, finding a right-sized model or controlling the number of false positives is notoriously difficult. Recently, a meta-algorithm called Stability Selection was proposed that can provide reliable…

Machine Learning · Statistics 2017-12-14 George Philipp , Seunghak Lee , Eric P. Xing

We present an efficient tensor-network-based approach for simulating large-scale quantum circuits, demonstrated using Quantum Support Vector Machines (QSVMs). Our method effectively reduces exponential runtime growth to near-quadratic…

We present preliminary results of the CIDA Equatorial Variability Survey (CEVS), looking for quasar (hereafter QSO) candidates near the Galactic plane. The CEVS contains photometric data from extended and adjacent regions of the Milky Way…

We present a catalog of 1,172,157 quasar candidates selected from the photometric imaging data of the Sloan Digital Sky Survey (SDSS). The objects are all point sources to a limiting magnitude of i=21.3 from 8417 sq. deg. of imaging from…

We identify 885,503 type 1 quasar candidates to i<22 using the combination of optical and mid-IR photometry. Optical photometry is taken from the Sloan Digital Sky Survey-III: Baryon Oscillation Spectroscopic Survey (SDSS-III/BOSS), while…

Thanks to the VISTA Variables in the Via Lactea (VVV) ESO Public Survey it is now possible to explore a large number of objects in those regions. This paper addresses the variability analysis of all VVV point sources having more than 10…

We describe the algorithm for selecting quasar candidates for optical spectroscopy in the Sloan Digital Sky Survey. Quasar candidates are selected via their non-stellar colors in "ugriz" broad-band photometry, and by matching unresolved…

For linear models that may have asymmetric errors, we study variable selection by cross-validation. The data are split into training and validation sets, with the number of observations in the validation set much larger than in the training…

Methodology · Statistics 2026-01-16 Bilel Bousselmi , Gabriela Ciuperca

The Hubble Space Telescope (HST) has obtained multi-epoch observations providing the opportunity for a comprehensive variability search aiming to uncover new variables. We have therefore undertaken the task of creating a catalog of variable…

The WISE satellite has detected hundreds of millions sources over the entire sky. Classifying them reliably is however a challenging task due to degeneracies in WISE multicolour space and low levels of detection in its two…

Astrophysics of Galaxies · Physics 2016-07-13 Agnieszka Kurcz , Maciej Bilicki , Aleksandra Solarz , Magdalena Krupa , Agnieszka Pollo , Katarzyna Małek

Quantum Machine Learning (QML) models of molecular HOMO-LUMO-gaps often struggle to achieve satisfying data-efficiency as measured by decreasing prediction errors for increasing training set sizes. Partitioning training sets of organic…

Chemical Physics · Physics 2021-10-07 Bernard Mazouin , Alexandre Alain Schöpfer , O. Anatole von Lilienfeld

{}From three quasar samples with a total of 1038 objects in the redshift range $1.0 \div 2.2$ we measure the variance $\sigma^2$ of counts in cells of volume $V_u$. By a maximum likelihood analysis applied separately on these samples we…

Astrophysics · Physics 2009-10-22 P. Andreani , S. Cristiani , F. Lucchin , S. Matarrese , L. Moscardini

We use [CII] observations of a large QSO sample to segregate sources by host galaxy mass, aiming to identify those in the most massive hosts. [CII] luminosity, a known tracer of molecular gas, is taken as a proxy for host mass and used to…

LSST is expected to yield ~10^7 light curves over the course of its mission, which will require a concerted effort in automated classification. Stochastic processes provide one means of quantitatively describing variability with the…

Instrumentation and Methods for Astrophysics · Physics 2017-04-26 J. C. Zinn , C. S. Kochanek , S. Kozłowski , A. Udalski , M. K. Szymański , I. Soszyński , Ł. Wyrzykowski , K. Ulaczyk , R. Poleski , P. Pietrukowicz , J. Skowron , P. Mróz , M. Pawlak