The CASSOWARY spectroscopy survey: A new sample of gravitationally lensed galaxies in SDSS

Abstract

Bright gravitationally lensed galaxies provide our most detailed view of galaxies at high redshift. Yet as a result of the small number of ultra-bright z~2 lensed systems with confirmed redshifts, most detailed spectroscopic studies have been limited in their scope. With the goal of increasing the number of bright lensed galaxies available for detailed follow-up, we have undertaken a spectroscopic campaign targeting wide separation (>3 arcsec) galaxy-galaxy lens candidates within the Sloan Digital Sky Survey (SDSS). Building on the earlier efforts of our CASSOWARY survey, we target a large sample of candidate galaxy-galaxy lens systems in SDSS using a well-established search algorithm which identifies blue arc-like structures situated around luminous red galaxies. In this paper, we present a new redshift catalog containing 25 lensed sources in SDSS confirmed through spectroscopic follow-up of candidate galaxy-galaxy lens systems. Included in this new sample are two of the brightest galaxies (r=19.6 and 19.7) galaxies known at z~2, a low metallicity (12 + log (O/H)~8.0) extreme nebular line emitting galaxy at z=1.43, and numerous systems for which detailed follow-up will be possible. The source redshifts span 0.9<z<2.5 (median redshift of 1.9), and their optical magnitudes are in the range 19.6<r<22.3. We present a brief source-by-source discussion of the spectroscopic properties extracted from our confirmatory spectra and discuss some initial science results. With more than 50 gravitationally lensed z>1 galaxies now confirmed within SDSS, it will soon be possible for the first time to develop generalized conclusions from detailed spectroscopic studies of the brightest lensed systems at high redshift.

17 pages, 6 figures, submitted to MNRAS

References in corpus (25)

• The COS-Halos Survey: An Empirical Description of the Metal-Line Absorption in the Low-Redshift Circumgalactic Medium
• The Characteristic Star Formation Histories of Galaxies at Redshifts z~2-7
• ALMA redshifts of millimeter-selected galaxies from the SPT survey: The redshift distribution of dusty star-forming galaxies
• The SINS/zC-SINF survey of z~2 galaxy kinematics: Outflow properties
• The CFHTLS Strong Lensing Legacy Survey: I. Survey overview and T0002 release sample
• Rest-Frame Optical Spectra of Three Strongly Lensed Galaxies at z~2
• The formation and assembly of a typical star-forming galaxy at z~3
• The Origin and Evolution of Metallicity Gradients: Probing the Mode of Mass Assembly at z=2
• The Cosmic Horseshoe: Discovery of an Einstein Ring around a Giant Luminous Red Galaxy
• A New Survey for Giant Arcs
• Models of the Cosmic Horseshoe Gravitational Lens
• Testing the Universality of the Fundamental Metallicity Relation at High Redshift Using Low-Mass Gravitationally Lensed Galaxies
• Gemini/GMOS Spectroscopy of 26 Strong Lensing Selected Galaxy Cluster Cores
• Two New Large Separation Gravitational Lenses from SDSS
• 3D-HST Grism Spectroscopy of a Gravitationally Lensed, Low-metallicity Starburst Galaxy at z=1.847
• SDSSJ2222+2745 A Gravitationally Lensed Sextuple Quasar with Maximum Image Separation of 15.1" Discovered in the Sloan Giant Arcs Survey
• Discovery of A Very Bright, Strongly-Lensed z=2 Galaxy in the SDSS DR5
• First direct metallicity measurement of a lensed star-forming galaxy at z=1.7
• The Redshift Distribution of Giant Arcs in the Sloan Giant Arcs Survey
• The Sloan Bright Arcs Survey : Six Strongly Lensed Galaxies at z=0.4-1.4
• The Sloan Bright Arcs Survey : Discovery of Seven New Strongly Lensed Galaxies from z=0.66-2.94
• SDSS J120923.7+264047: A new massive galaxy cluster with a bright giant arc
• X-shooter Observations of the Gravitational Lens System CASSOWARY 5
• The SDSS Discovery of a Strongly Lensed Post-Starburst Galaxy at z=0.766
• The dark matter halo concentration and stellar initial mass function of a CASSOWARY group

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• HOLISMOKES -- II. Identifying galaxy-scale strong gravitational lenses in Pan-STARRS using convolutional neural networks
• Discovery of Strongly Inverted Metallicity Gradients in Dwarf Galaxies at $z$$\sim$2
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• The MOSDEF Survey: Detection of [OIII]$\lambda$4363 and the direct-method oxygen abundance of a star-forming galaxy at z=3.08
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• HOLISMOKES. VIII. High-redshift, strong-lens search in the Hyper Suprime-Cam Subaru Strategic Program
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• Dust in the Wind: Composition and Kinematics of Galaxy Outflows at the Peak Epoch of Star Formation
• Star Formation at z=2.481 in the Lensed Galaxy SDSS J1110+6459, I: Lens Modeling and Source Reconstruction
• PICS: Simulations of Strong Gravitational Lensing in Galaxy Clusters
• Properties of five z~0.3-0.4 confirmed LyC leakers: VLT/XShooter observations
• Prediction of Supernova Rates in Known Galaxy-galaxy Strong-lens Systems
• Hubble Asteroid Hunter: II. Identifying strong gravitational lenses in HST images with crowdsourcing
• The Detection of [O III]$\lambda$4363 in a Lensed, Dwarf Galaxy at $z$ = 2.59: Testing Metallicity Indicators and Scaling Relations at High Redshift and Low Mass
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• The physical nature of the 8 o'clock arc based on near-IR IFU spectroscopy with SINFONI
• Stellar Velocity Dispersion for a Strongly-Lensed, Intermediate-Mass Quiescent Galaxy at z=2.8
• CLASH: Extending galaxy strong lensing to small physical scales with distant sources highly-magnified by galaxy cluster members
• Astrophysical Tests of Dark Matter Self-Interactions
• COOL-LAMPS I. An Extraordinarily Bright Lensed Galaxy at Redshift 5.04
• Constraining the multi-scale dark-matter distribution in CASSOWARY 31 with strong gravitational lensing and stellar dynamics
• A Comparison of Rest-frame Ultraviolet and Optical Emission-Line Diagnostics in the Lensed Galaxy SDSS J1723+3411 at Redshift z=1.3293
• Identification of Galaxy-Galaxy Strong Lens Candidates in the DECam Local Volume Exploration Survey Using Machine Learning
• The evolution of late-type galaxies from CASSOWARY lensing systems
• Spatial Variation in Strong Line Ratios and Physical Conditions in Two Strongly-Lensed Galaxies at z~1.4
• The Canarias Einstein Ring: a Newly Discovered Optical Einstein Ring
• Precision cosmology with time delay lenses: high resolution imaging requirements
• High Resolution spatial analysis of a z $\sim$ 2 lensed galaxy using adaptive coadded source-plane reconstruction
• The DES Bright Arcs Survey: Candidate Strongly Lensed Galaxy Systems from the Dark Energy Survey 5,000 Sq. Deg. Footprint
• The importance of secondary halos for strong lensing in massive galaxy clusters across redshift
• An extended catalog of galaxy-galaxy strong gravitational lenses discovered in DES using convolutional neural networks
• Spectroscopy of CASSOWARY gravitationally-lensed galaxies in SDSS: characterisation of an extremely bright reionization-era analog at $z=1.42$
• Rest-frame UV and optical emission line diagnostics of ionised gas properties: a test case in a star-forming knot of a lensed galaxy at z~1.7
• Reconstructing the extended structure of multiple sources strongly lensed by the ultra-massive elliptical galaxy SDSS J0100+1818
• Molecular gas budget and characterization of intermediate-mass star-forming galaxies at $z\approx 2-3$
• ALMA Lensing Cluster Survey: A spectral stacking analysis of [CII] in lensed $z\sim 6$ galaxies
• Using Strong Gravitational Lensing to Identify Fossil Group Progenitors
• The Direct-Method Oxygen Abundance of Typical Dwarf Galaxies at Cosmic High-Noon
• LBT/ARGOS adaptive optics observations of z$\sim 2$ lensed galaxies
• SDSS J1640+1932: a spectacular galaxy-quasar strong lens system
• A Computer Vision Approach To Identify Einstein Rings And Arcs
• Chandra and HST Snapshots of Fossil System Progenitors
• Modelling of long gamma-ray burst host galaxies at cosmic noon from damped Lyman-α absorption statistics
• Cosmography from accurate mass modeling of the lens group SDSS J0100+1818: five sources at three different redshifts
• Pixel-level modelling of group-scale strong lens CASSOWARY 19
• Detection of extremely low frequency gravitational wave using gravitational lens
• Strong-lensing and kinematic analysis of CASSOWARY 31: can strong lensing constrain the masses of multi-plane lenses?
• COOL-LAMPS IV: A Sample of Bright Strongly-Lensed Galaxies at $3<z<4$
• SDSS J1059+4251, a highly magnified z ~ 2.8 star-forming galaxy: ESI observations of the rest-frame UV spectrum
• Along the Primary Curve: Simultaneous Source and Lens Reconstruction of Bright Arcs in Cluster Lenses
• Resolving star-forming clumps in a z $\sim$ 2 lensed galaxy: a pixelated Bayesian approach
• Confirming HSC strong lens candidates with DESI Spectroscopy. I. Project overview and first results
• The AGEL Survey: Spectroscopic Confirmation of Strong Gravitational Lenses in the DES and DECaLS Fields Selected Using Convolutional Neural Networks
• Core Mass Estimates in Strong Lensing Galaxy Clusters: a Comparison Between Masses Obtained from Detailed Lens Models, Single-Halo Lens Models, and Einstein Radii
• The lens SW05 J143454.4+522850: a fossil group at redshift 0.6?