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Related papers: Improved Redshifts for DESI EDR Quasars

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Forthcoming astronomical surveys are expected to detect new sources in such large numbers that measuring their spectroscopic redshift measurements will be not be practical. Thus, there is much interest in using machine learning to yield the…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-14 S. J. Curran

We present the largest catalog to date of triply ionized carbon (CIV) absorbers detected in quasar spectra from the Dark Energy Spectroscopic Instrument. Using an automated matched-kernel convolution method with adaptive signal-to-noise…

We have imaged 45 quasars from the Sloan Digital Sky Survey (SDSS) with redshifts 1.85 < z < 4.26 in JHKs with the KPNO SQIID imager. By combining these data with optical magnitudes from the SDSS we have computed the restframe optical…

Astrophysics · Physics 2009-11-13 Julia Kennefick , Shelly Bursick

Optical and near-infrared (NIR) spectra are presented for ULAS J131911.29+095951.4 (hereafter ULAS J1319+0950), a new redshift z = 6.127 +/- 0.004 quasar discovered in the Third Data Release (DR3) of the UKIRT Infrared Deep Sky Survey…

Upcoming surveys such as Euclid, the Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST) and the Nancy Grace Roman Telescope (Roman) will detect hundreds of high-redshift (z > 7) quasars, but distinguishing them from the…

Instrumentation and Methods for Astrophysics · Physics 2025-07-31 Lena Lenz , Daniel J. Mortlock , Boris Leistedt , Rhys Barnett , Paul C. Hewett

Proceeding of the "HACK100" Conference, 6-10 June 2022, Trieste, Italy - In recent years, quasars have been shown to be reliable standardizable candles, thanks to the non-linear relation between their X-rays and ultraviolet luminosity.…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-17 Matilde Signorini , Guido Risaliti , Andrea Sacchi , Elisabeta Lusso , Emanuele Nardini

We report detections of six high-redshift (1.8 < z < 6.4), optically luminous, radio-quiet quasars at 350 micron, using the SHARC II bolometer camera at the Caltech Submillimeter Observatory. Our observations double the number of…

Astrophysics · Physics 2009-11-11 A. Beelen , P. Cox , D. J. Benford , C. D. Dowell , A. Kovacs , F. Bertoldi , A. Omont , C. L. Carilli

We report the first results of an observational program designed to determine the luminosity density of high redshift quasars (z > 5 quasars) using deep multi-colour CCD data. We report the discovery and spectra of 3 i < 21.5 high redshift…

Astrophysics · Physics 2018-05-09 R. G. Sharp , R. G. McMahon , M. J. Irwin , S. T. Hodgkin

A Sloan Digital Sky Survey (SDSS) source sample containing 44,200 quasar redshifts is examined. Although arguments have been put forth to explain some of the structure observed in the redshift distribution, it is argued here that this…

Astrophysics · Physics 2007-05-23 M. B. Bell

We present a new approach to capturing the broad diversity of emission line and continuum properties in quasar spectra. We identify populations of spectrally similar quasars through pixel-level clustering on 12,968 high signal-to-noise…

Astrophysics of Galaxies · Physics 2022-02-16 Allyson Brodzeller , Kyle Dawson

Highly multiplexed, fiber-fed spectroscopy is enabling surveys of millions of stars and galaxies. The performance of these surveys depends on accurately positioning fibers in the focal plane to capture target light. We describe a technique…

We report on exploratory Chandra observations of the three highest redshift quasars known (z = 5.82, 5.99, and 6.28), all found in the Sloan Digital Sky Survey. These data, combined with a previous XMM-Newton observation of a z = 5.74…

We searched for the presence of extended emission-line regions (EELRs) around low-redshift QSOs. We observed a sample of 20 mainly radio-quiet low-redshift quasars (z<0.3) by means of integral field spectroscopy. After decomposing the…

Astrophysics · Physics 2009-11-13 B. Husemann , L. Wisotzki , S. F. Sánchez , K. Jahnke

We have observed a sample of 22 luminous quasars, in the range 2.0<z<2.5, at 1.6 microns with the near-infrared (NIR) spectrograph FSPEC on the Multiple Mirror Telescope. Our sample contains 13 radio-loud and 9 radio-quiet objects. We have…

Astrophysics · Physics 2009-10-31 D. H. McIntosh , H. -W. Rix , M. J. Rieke , C. B. Foltz

The Sloan Digital Sky Survey has obtained images in five broad-band colors for several hundred square degrees. We present color-color diagrams for stellar objects, and demonstrate that quasars are easily distinguished from stars by their…

The recently commissioned Dark Energy Spectroscopic Instrument (DESI) will measure the expansion history of the Universe using the Baryon Acoustic Oscillation technique. The spectra of 35 million galaxies and quasars over 14000 sqdeg will…