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Related papers: Detecting Quasars in Large-Scale Astronomical Surv…

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Utilizing the latest and the most sensitive radio and optical catalogs, we completed a new blazar candidate catalog, Blazar Radio and Optical Survey (BROS), which includes 88,211 sources located at declination $\delta > -40^{\circ}$ and…

High Energy Astrophysical Phenomena · Physics 2020-08-04 Ryosuke Itoh , Yousuke Utsumi , Yoshiyuki Inoue , Kouji Ohta , Akihiro Doi , Tomoki Morokuma , Koji S. Kawabata , Yasuyuki T. Tanaka

We review the statistical properties of the main populations of radio sources, as emerging from radio and millimeter sky surveys. Recent determinations of local luminosity functions are presented and compared with earlier estimates still in…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Gianfranco De Zotti , Marcella Massardi , Mattia Negrello , Jasper Wall

We measure the clustering of a sample of photometrically selected luminous red galaxies around a low redshift (0.2<z<0.6) sample of quasars selected from the Sloan Digital Sky Survey Data Release 5. We make use of a new statistical…

Astrophysics · Physics 2015-05-13 N. Padmanabhan , M. White , P. Norberg , C. Porciani

Modern radio telescope surveys, capable of detecting billions of galaxies in wide-field surveys, have made manual morphological classification impracticable. This applies in particular when the Square Kilometre Array Observatory (SKAO)…

Astrophysics of Galaxies · Physics 2026-01-09 Philipp Denzel , Manuel Weiss , Elena Gavagnin , Frank-Peter Schilling

We present a method for the photometric selection of candidate quasars in multiband surveys. The method makes use of a priori knowledge derived from a subsample of spectroscopic confirmed QSOs to map the parameter space. The disentanglement…

Astrophysics · Physics 2015-05-13 R. D'Abrusco , G. Longo , N. A. Walton

We apply a recently developed method for classifying broad absorption line quasars (BALQSOs) to the latest QSO catalogue constructed from Data Release 5 of the Sloan Digital Sky Survey. Our new hybrid classification scheme combines the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 S. Scaringi , C. E. Cottis , C. Knigge , M. R. Goad

The Sloan Digital Sky Survey-II Supernova Survey has identified a large number of new transient sources in a 300 sq. deg. region along the celestial equator during its first two seasons of a three-season campaign. Multi-band (ugriz) light…

In this contribution we would like to emphasize the usefulness of data mining multiwavelength surveys like the Sloan Digital Sky Survey (SDSS) or the ROSAT All Sky Survey (RASS) -- which have become available to the public recently -- in…

Astrophysics · Physics 2007-05-23 J. Zuther , A. Eckart , W. Voges , T. Bertram , C. Straubmeier

Slitless spectroscopy is a traditional method for selecting quasars. In this paper, we develop a procedure for selecting quasars (QSOs) using the 3D-HST G141 slitless spectra. We initially identify over 6,000 sources with emission lines…

Astrophysics of Galaxies · Physics 2025-05-21 Yuxuan Pang , Xue-Bing Wu , Yuming Fu , Rui Zhu , Tao Ji , Qinchun Ma , Xiaotong Feng

Optical spectra of galaxies and quasars from large cosmological surveys are used to measure redshifts and infer distances. They are also rich with information on the intrinsic properties of these astronomical objects. However, their…

I summarize the current spectroscopic sky surveys and some of the scientific results, emphasizing the largest sky survey to-date, the Sloan Digital Sky Survey (SDSS). Techniques used commonly in spectral analyses are discussed, followed by…

Astrophysics · Physics 2007-07-02 Ching-Wa Yip

We develop an automated technique for detecting damped Lyman-$\alpha$ absorbers (DLAs) along spectroscopic lines of sight to quasi-stellar objects (QSOs or quasars). The detection of DLAs in large-scale spectroscopic surveys such as…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-17 Roman Garnett , Shirley Ho , Simeon Bird , Jeff Schneider

We identified a large sample of radio quasars, including those with complex radio morphology, from the Sloan Digital Sky Survey (SDSS) and the Faint Images of Radio Sky at Twenty-cm (FIRST). Using this sample, we inspect previous radio…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-21 Yu Lu , Tinggui Wang , Hongyan Zhou , Jian Wu

Robust fast methods to classify variable light curves in large sky surveys are becoming increasingly important. While it is relatively straightforward to identify common periodic stars and particular transient events (supernovae, novae,…

We report the discovery of five quasars with redshifts of 4.67 - 5.27 and z'-band magnitudes of 19.5-20.7 M_B ~ -27. All were originally selected as distant quasar candidates in optical/near-infrared photometry from the Sloan Digital Sky…

We test the hypothesis that the polarization vectors of flat-spectrum radio sources (FSRS) in the JVAS/CLASS 8.4-GHz surveys are randomly oriented on the sky. The sample with robust polarization measurements is made of $4155$ objects and…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-24 Vincent Pelgrims , Damien Hutsemékers

We present a high-resolution radio survey of the Sloan Digital Sky Survey (SDSS) Southern Equatorial Stripe, a.k.a. Stripe 82. This 1.4 GHz survey was conducted with the Very Large Array (VLA) primarily in the A-configuration, with…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-29 J. A. Hodge , R. H. Becker , R. L. White , G. T. Richards , G. R. Zeimann

Sky surveys are the largest data generators in astronomy, making automated tools for extracting meaningful scientific information an absolute necessity. We show that, without the need for labels, self-supervised learning recovers…

Instrumentation and Methods for Astrophysics · Physics 2022-06-30 Md Abul Hayat , George Stein , Peter Harrington , Zarija Lukić , Mustafa Mustafa

Finding and classifying astronomical sources is key in the scientific exploitation of radio surveys. Source-finding usually involves identifying the parts of an image belonging to an astronomical source, against some estimated background.…

Instrumentation and Methods for Astrophysics · Physics 2019-12-20 V. Lukic , F. De Gasperin , M. Brüggen

We present a data-driven technique to analyze multifrequency images from upcoming cosmological surveys mapping large sky area. Using full information from the data at the two-point level, our method can simultaneously constrain the…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-01 Yun-Ting Cheng , Benjamin D. Wandelt , Tzu-Ching Chang , Olivier Dore
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