MALS-NOT: Identifying Radio-Bright Quasars for the MeerKAT Absorption Line Survey

Abstract

We present a preparatory spectroscopic survey to identify radio-bright, high-redshift quasars for the MeerKAT Absorption Line Survey (MALS). The candidates have been selected on the basis of a single flux density limit at 1.4 GHz (>200 mJy) together with mid-infrared color criteria from the Wide-field Infrared Survey Explorer (WISE). Through spectroscopic observations using the Nordic Optical Telescope, we identify 72 quasars out of 99 candidates targeted. We measure the spectroscopic redshifts based on characteristic, broad emission lines present in the spectra. Of these 72 quasars, 64 and 48 objects are at sufficiently high redshift (z>0.6 and z>1.4) to be used for the L-band and UHF-band spectroscopic follow-up with the Square Kilometre Array (SKA) precursor in South Africa: the MeerKAT.

arXiv commentAccepted for publication in ApJS. Supplementary figure sets available in the source files

References in corpus (41)

• The Sloan Digital Sky Survey: Technical Summary
• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• Cosmic-Ray Rejection by Laplacian Edge Detection
• SUMSS: A Wide-Field Radio Imaging Survey of the Southern Sky. II. The Source Catalogue
• Mid-Infrared Selection of AGN with the Wide-Field Infrared Survey Explorer. I. Characterizing WISE-Selected AGN in COSMOS
• The Sloan Digital Sky Survey Quasar Catalog: twelfth data release
• SUMSS: A Wide-Field Radio Imaging Survey of the Southern Sky. I. Science goals, survey design and instrumentation
• Low Resolution Spectral Templates For AGNs and Galaxies From 0.03 -- 30 microns
• Science With The Australian Square Kilometre Array Pathfinder
• The CORALS Survey I: New Estimates of the Number Density and Gas Content of Damped Lyman Alpha Systems Free from Dust Bias
• The VLT-UVES survey for molecular hydrogen in high-redshift damped Lyman-alpha systems: Physical conditions in the neutral gas
• A deep search for 21cm absorption in high redshift damped Lyman-$\alpha$ systems
• Constraints on changes in fundamental constants from a cosmologically distant OH absorber/emitter
• The spin temperature of high-redshift damped Lyman-$\alpha$ systems
• Kinematics and physical conditions of HI in nearby radio sources. The last survey of the old Westerbork Synthesis Radio Telescope
• Discovery of a Perseus-like cloud in the early Universe: HI-to-H2 transition, carbon monoxide and small dust grains at zabs=2.53 towards the quasar J0000+0048
• The dust obscuration bias in Damped Lyman alpha systems
• The UCSD Radio-Selected Quasar Survey for Damped Lyman alpha System
• The Optical - Infrared Colors of CORALS QSOs: Searching for Dust Reddening Associated With High Redshift Damped Lyman Alpha Systems
• The MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) Survey
• Bayesian High-Redshift Quasar Classification from Optical and Mid-IR Photometry
• Faraday Rotation from Magnesium II Absorbers towards Polarized Background Radio Sources
• Search for cold gas in z>2 damped Lyman-alpha systems: 21-cm and H_2 absorption
• Optical/near-infrared selection of red QSOs: Evidence for steep extinction curves towards galactic centers?
• A complete sample of 21-cm absorbers at z~1.3: Giant Metrewave Radio Telescope Survey Using MgII Systems
• Unusual quasars from the Sloan Digital Sky Survey selected by means of Kohonen self-organising maps
• Dust Reddened Quasars in FIRST and UKIDSS: Beyond the Tip of the Iceberg
• Search for cold gas in strong MgII absorbers at 0.5<z<1.5: nature and evolution of 21-cm absorbers
• A Laboratory for Constraining Cosmic Evolution of the Fine Structure Constant: Conjugate 18 cm OH Lines Toward PKS 1413+135 at z=0.2467
• Constraining the variation of fundamental constants at z ~ 1.3 using 21-cm absorbers
• H I Column Densities, Metallicities, and Dust Extinction of Metal-Strong Damped Lya Systems
• Dust Biasing of Damped Lyman Alpha Systems: a Bayesian Analysis
• Illuminating the past 8 billion years of cold gas towards two gravitationally lensed quasars
• Conjugate 18cm OH Satellite Lines at a Cosmological Distance
• The High A(V) Quasar Survey: Reddened quasi-stellar objects selected from optical/near-infrared photometry - II
• Neutral atomic-carbon QSO absorption-line systems at z>1.5: Sample selection, HI content, reddening, and 2175 A extinction feature
• The extended High A(V) Quasar Survey: Searching for dusty absorbers toward mid-infrared selected quasars
• New searches for HI 21-cm in damped Lyman-alpha absorption systems
• The dust content of damped Lyman-alpha systems in the Sloan Digital Sky Survey
• Incidence of HI 21-cm absorption in strong FeII systems at $0.5<z<1.5$
• Broad-band spectral energy distribution of 3000 Angstroem break quasars from the Sloan Digital Sky Survey

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• The ASKAP-EMU Early Science Project: 888 MHz Radio Continuum Survey of the Large Magellanic Cloud
• Evolution of cold gas at 2<z<5: a blind search for HI and OH absorption lines towards mid-infrared color selected radio-loud AGNs
• Using Neural Networks to Differentiate Newly Discovered BL Lacs and FSRQs among the 4FGL Unassociated Sources Employing Gamma-ray, X-ray, UV/Optical and IR Data
• MALS SALT-NOT survey of MIR-selected powerful radio-bright AGN at 0<z<3.5
• Spatially resolved Lyman-$\alpha$ emission around radio bright quasars
• Proximate molecular quasar absorbers: Chemical enrichment and kinematics of the neutral gas
• HI gas playing hide-and-seek around a powerful FRI-type quasar at z$\sim$2.1
• Lyman-$\alpha$ emission from a WISE-selected optically faint powerful radio galaxy M151304.72-252439.7 at $z$ = 3.132
• Radio properties of high-redshift galaxies at $z\ge 1$
• Discovery of 178 Giant Radio Galaxies in 1059 deg${}^2$ of the Rapid ASKAP Continuum Survey at 888 MHz