English
Related papers

Related papers: A Simple Likelihood Method for Quasar Target Selec…

200 papers

We present a classification-based approach to identify quasi-stellar radio sources (quasars) in the Sloan Digital Sky Survey and evaluate its performance on a manually labeled training set. While reasonable results can already be obtained…

Instrumentation and Methods for Astrophysics · Physics 2016-11-18 Fabian Gieseke , Kai Lars Polsterer , Andreas Thom , Peter-Christian Zinn , Dominik Bomanns , Ralf-Jürgen Dettmar , Oliver Kramer , Jan Vahrenhold

We present a measurement of the quasar luminosity function in the range 0.68<z<4 down to extinction corrected magnitude g_dered=22.5, using a simple and well understood target selection technique based on the time-variability of quasars.…

We develop a method for separating quasars from other variable point sources using SDSS Stripe 82 light curve data for ~10,000 variable objects. To statistically describe quasar variability, we use a damped random walk model parametrized by…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-28 C. L. MacLeod , K. Brooks , Z. Ivezic , C. S. Kochanek , R. Gibson , A. Meisner , S. Kozlowski , B. Sesar , A. C. Becker , W. de Vries

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 Sloan Digital Sky Survey (SDSS) will observe around 10^6 spectra from targets distributed over an area of about 10,000 square degrees, using a multi-object fiber spectrograph which can simultaneously observe 640 objects in a circular…

Astrophysics · Physics 2010-11-04 M. R. Blanton , R. H. Lupton , F. Miller Maley , N. Young , I. Zehavi , J. Loveday

We present a new selection technique of producing spectroscopic target catalogues for massive spectroscopic surveys for cosmology. This work was conducted in the context of the extended Baryon Oscillation Spectroscopic Survey (eBOSS), which…

We present the second report of our systematic search for strongly lensed quasars from the data of the Sloan Digital Sky Survey (SDSS). From extensive follow-up observations of 136 candidate objects, we find 36 lenses in the full sample of…

We present the first application of the weighted skew-spectra to analyze non-Gaussian information in galaxy survey data. Using the tree-level galaxy skew-spectra together with the one-loop power spectrum multipoles, we analyze the Sloan…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-25 Shu-Fan Chen , Priyesh Chakraborty , Cora Dvorkin

In this paper we present the first results of a deep spectroscopic survey of faint quasars in the Sloan Digital Sky Survey (SDSS) Southern Survey, a deep survey carried out by repeatedly imaging a 270 deg^2 area. Quasar candidates were…

We present measurements of the spectral properties for a total of 526,265 quasars, out of which 63% have continuum S/N$>3$ pixel$^{-1}$, selected from the fourteenth data release of the Sloan Digital Sky Survey (SDSS-DR14) quasar catalog.…

Astrophysics of Galaxies · Physics 2020-07-29 Suvendu Rakshit , C. S. Stalin , Jari Kotilainen

We present a catalogue of about 6 million unresolved photometric detections in the Sloan Digital Sky Survey Seventh Data Release classifying them into stars, galaxies and quasars. We use a machine learning classifier trained on a subset of…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 Sheelu Abraham , Ninan Sajeeth Philip , Ajit Kembhavi , Yogesh G Wadadekar , Rita Sinha

We determine the number counts and z=0-5 luminosity function for a well-defined, homogeneous sample of quasars from the Sloan Digital Sky Survey (SDSS). We conservatively define the most uniform statistical sample possible, consisting of…

We present the design and performance of the multi-object fiber spectrographs for the Sloan Digital Sky Survey (SDSS) and their upgrade for the Baryon Oscillation Spectroscopic Survey (BOSS). Originally commissioned in Fall 1999 on the…

We have conducted a pilot survey for z>3.5 quasars by combining the FIRST radio survey with the SDSS. While SDSS already targets FIRST sources for spectroscopy as quasar candidates, our survey includes fainter quasars and greatly improves…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Ian D. McGreer , David J. Helfand , Richard L. White

We describe the algorithm used to select the Emission Line Galaxy (ELG) sample at $z \sim 0.85$ for the extended Baryon Oscillation Spectroscopic Survey of the Sloan Digital Sky Survey IV, using photometric data from the DECam Legacy…

The Baryon Acoustic Oscillation (BAO) feature in the power spectrum of galaxies provides a standard ruler to probe the accelerated expansion of the Universe. The current surveys covering a comoving volume sufficient to unveil the BAO scale…

We present a study of candidate galaxy-absorber pairs for 43 low redshift QSO sightlines ($0.06 < z < 0.85$) observed with the {\it Hubble Space Telescope}/Cosmic Origins Spectrograph that lie within the footprint of the Sloan Digital Sky…

Astrophysics of Galaxies · Physics 2021-12-22 Jennifer E. Scott , Emileigh S. Shoemaker , Colin D. Hamill

We present a lensing study of 42 galaxy clusters imaged in Sloan Digital Sky Survey (SDSS) commissioning data. Cluster candidates are selected optically from SDSS imaging data and confirmed for this study by matching to X-ray sources found…

Difference imaging provides a new way to discover gravitationally lensed quasars because few non-lensed sources will show spatially extended, time variable flux. We test the method on lens candidates in the Sloan Digital Sky Survey (SDSS)…