EZ: A Tool for Automatic Redshift Measurement

Abstract

We present EZ (Easy redshift), a tool we have developed within the VVDS project to help in redshift measurement from otpical spectra. EZ has been designed with large spectroscopic surveys in mind, and in its development particular care has been given to the reliability of the results obtained in an automatic and unsupervised mode. Nevertheless, the possibility of running it interactively has been preserved, and a graphical user interface for results inspection has been designed. EZ has been successfully used within the VVDS project, as well as the zCosmos one. In this paper we describe its architecture and the algorithms used, and evaluate its performances both on simulated and real data. EZ is an open source program, freely downloadable from http://cosmos.iasf-milano.inaf.it/pandora.

accepted for publication in Publications of the Astronomical Society of the Pacific

Cited by in corpus (94)

• The VIMOS VLT Deep Survey final data release: a spectroscopic sample of 35016 galaxies and AGN out to z~6.7 selected with 17.5<=i_{AB}<=24.7
• The VIMOS Ultra-Deep Survey: ~10,000 galaxies with spectroscopic redshifts to study galaxy assembly at early epochs 2<z<~6
• The VIMOS Public Extragalactic Survey (VIPERS): First Data Release of 57 204 spectroscopic measurements
• The VIMOS Public Extragalactic Redshift Survey (VIPERS). Full spectroscopic data and auxiliary information release (PDR-2)
• Galaxy And Mass Assembly (GAMA): autoz spectral redshift measurements, confidence and errors
• The VANDELS ESO public spectroscopic survey: observations and first data release
• A refined mass distribution of the cluster MACS J0416.1$-$2403 from a new large set of spectroscopic multiply lensed sources
• CLASH-VLT: Dissecting the Frontier Fields Galaxy Cluster MACS J0416.1-2403 with $\sim 800$ Spectra of Member Galaxies
• MARZ: Manual and Automatic Redshifting Software
• The VIMOS Ultra Deep Survey First Data Release: spectra and spectroscopic redshifts of 698 objects up to z~6 in CANDELS
• The VIMOS Public Extragalactic Redshift Survey (VIPERS). A precise measurement of the galaxy stellar mass function and the abundance of massive galaxies at redshifts 0.5<z<1.3
• The MUSE-Wide Survey: A first catalogue of 831 emission line galaxies
• Discovery of a rich proto-cluster at z=2.9 and associated diffuse cold gas in the VIMOS Ultra-Deep Survey (VUDS)
• A first look at the SMACS0723 JWST ERO: spectroscopic redshifts, stellar masses and star-formation histories
• The X-ray luminous galaxy cluster population at 0.9<z<~1.6 as revealed by the XMM-Newton Distant Cluster Project
• Spot the difference. Impact of different selection criteria on observed properties of passive galaxies in zCOSMOS 20-k sample
• The VIMOS Public Extragalactic Redshift Survey (VIPERS): A quiescent formation of massive red-sequence galaxies over the past 9 Gyr
• The X-ray luminous galaxy cluster XMMU J1007.4+1237 at z=1.56 - The dawn of starburst activity in cluster cores
• Ly$\alpha$-Lyman Continuum connection in 3.5 < z < 4.3 star-forming galaxies from the VUDS survey
• The MUSE Deep Lensed Field on the Hubble Frontier Field MACS~J0416
• Obscured AGN at z~1 from the zCOSMOS-Bright Survey I. Selection and Optical Properties of a [Ne v]-selected sample
• LSDCat: Detection and cataloguing of emission-line sources in integral-field spectroscopy datacubes
• The VIMOS Ultra-Deep Survey: evidence for AGN feedback in galaxies with CIII]-$\lambda$1908Å~emission 10.8 to 12.5 Gyr ago
• Size evolution of star-forming galaxies with $2<z<4.5$ in the VIMOS Ultra-Deep Survey
• The VIMOS Public Extragalactic Redshift Survey (VIPERS): Downsizing of the blue cloud and the influence of galaxy size on mass quenching over the last eight billion years
• The role of major mergers in shaping galaxies at 2<z<4 in the VUDS and VVDS surveys
• Obscured AGN at 1.5 < z < 3.0 from the zCOSMOS-deep Survey I. Properties of the emitting gas in the Narrow Line Region
• The VANDELS survey: the relation between UV continuum slope and stellar metallicity in star-forming galaxies at z~3
• The UV and Ly$\alpha$ Luminosity Functions of galaxies and the Star Formation Rate Density at the end of HI reionization from the VIMOS Ultra-Deep Survey (VUDS)
• The evolution of clustering length, large-scale bias and host halo mass at 2<z<5 in the VIMOS Ultra Deep Survey (VUDS)
• The impact of spectroscopic incompleteness in direct calibration of redshift distributions for weak lensing surveys
• A large-scale galaxy structure at z = 2.02 associated with the radio galaxy MRC0156-252
• Spectroscopic observations of PHz G237.01+42.50: A galaxy protocluster at z=2.16 in the Cosmos field
• CLASH-VLT: Abell~S1063. Cluster assembly history and spectroscopic catalogue
• Characterization of star-forming dwarf galaxies at 0.1 $\lesssim z\lesssim$ 0.9 in VUDS: Probing the low-mass end of the mass-metallicity relation
• The VIMOS Ultra-Deep Survey: A major merger origin for the high fraction of galaxies at $2<z<6$ with two bright clump
• Probing deviations from General Relativity with the Euclid spectroscopic survey
• Detectability of Torsion Gravity via Galaxy Clustering and Cosmic Shear Measurements
• The VANDELS survey: the role of ISM and galaxy physical properties on the escape of Lyα emission in z $\sim$ 3.5 star-forming galaxies
• The identification of post-starburst galaxies at z~1 using multiwavelength photometry: a spectroscopic verification
• Constraining Lyman-alpha spatial offsets at $3<z<5.5$ from VANDELS slit spectroscopy
• The stellar metallicities of massive quiescent galaxies at 1.0 < z < 1.3 from KMOS+VANDELS
• High-velocity outflows in massive post-starburst galaxies at z > 1
• Easylife: the data reduction and survey handling system for VIPERS
• Galaxy pre-processing in substructures around z$\sim$0.4 galaxy clusters
• The VIMOS Ultra Deep Survey. Luminosity and stellar mass dependence of galaxy clustering at z~3
• The extended epoch of galaxy formation: age dating of ~3600 galaxies with 2<z<6.5 in the VIMOS Ultra-Deep Survey
• An high definition view of the COSMOS Wall at z~0.73
• The VIMOS Ultra-Deep Survey (VUDS): IGM transmission towards galaxies with 2.5<z<5.5 and the colour selection of high redshift galaxies
• The environment of AGN dwarf galaxies at z$\sim$0.7 from the VIPERS survey
• The Cosmic Web and galaxy evolution around the most luminous X-ray cluster: RXJ1347.5-1145
• The ionizing photon production efficiency of bright z$\sim$2-5 galaxies
• SFR estimations from z=0 to z=0.9 -- A comparison of SFR calibrators for star-forming galaxies
• From the core to the outskirts: structure analysis of three massive galaxy clusters
• The VANDELS survey: Discovery of massive overdensities of galaxies at z>2
• The XXL Survey VIII: MUSE characterisation of intracluster light in a z$\sim$0.53 cluster of galaxies
• Comparison of the properties of two fossil groups of galaxies with the normal group NGC 6034 based on multiband imaging and optical spectroscopy
• Searching for filaments and large-scale structure around DAFT/FADA clusters
• The PAU Survey: narrowband photometric redshifts using Gaussian processes
• In the whirlpool's coils: tracing substructure from combined optical/X-ray data in the galaxy cluster A1300
• Properties of the interstellar medium in star-forming galaxies at redshifts 2 < z < 5 from the VANDELS survey
• Comparison of hydrostatic and dynamical masses of distant X-ray luminous galaxy clusters
• The VANDELS ESO public spectroscopic survey: The spectroscopic measurements catalogue
• Kinematic analysis of a sample of X-ray luminous distant galaxy clusters. The $L_X$ - ${\sigma }_v$ relation in the $z>0.6$ universe
• Growing up in a megalopolis: Environmental effects on galaxy evolution in a supercluster at z~0.65 in UKIDSS UDS
• Insights into the reionization epoch from cosmic-noon-CIV emitters in the VANDELS survey
• Darth Fader: Using wavelets to obtain accurate redshifts of spectra at very low signal-to-noise
• Compact star-forming galaxies preferentially quenched to become PSBs in $z<1$ clusters
• The PAU Survey: Measurements of the 4000 Å spectral break with narrow-band photometry
• High-velocity outflows persist up to 1 Gyr after a starburst in recently-quenched galaxies at z > 1
• Spectroscopy of the Supernova H0pe Host Galaxy at Redshift 1.78
• Detecting the Highest Redshift (z > 8) QSOs in a Wide, Near Infrared Slitless Spectroscopic Survey
• The fundamental metallicity relation from SDSS (z~0) to VIPERS (z~0.7) Data selection or evolution
• The Intergalactic medium transmission towards z>4 galaxies with VANDELS and the impact of dust attenuation
• Exploring the galaxy cluster-group transition regime at high redshifts: Physical properties of two newly detected z > 1 systems
• Discovery of the X-ray selected galaxy cluster XMMU J0338.8+0021 at z = 1.49 - Indications for a young system with a forming brightest galaxy
• Metal content of the circumgalactic medium around star-forming galaxies at z $\sim$ 2.6 as revealed by the VIMOS Ultra-Deep Survey
• Probing cluster dynamics in RXCJ1504.1-0248 via radial and two-dimensional gas and galaxy properties
• An accurate strong lensing model of the Abell 2163 core
• Influence of star-forming galaxy selection on the galaxy main sequence
• The less and the more IGM transmitted galaxies from z~2.7 to z~6 from VANDELS and VUDS
• Decoding the IRX-β dust attenuation relation in star-forming galaxies at intermediate redshift
• The most massive, passive, and oldest galaxies at 0.5 < z < 2.1: Downsizing signature from galaxies selected from MgUV index
• The VIMOS Public Extragalactic Redshift Survey (VIPERS): PCA-based automatic cleaning and reconstruction of survey spectra
• Automated reliability assessment for spectroscopic redshift measurements
• Distant galaxy clusters in a deep XMM-Newton field within the CFTHLS D4
• Probing the dynamical and X-ray mass proxies of the cluster of galaxies Abell S1101
• The powerful lens galaxy cluster PLCK G287.0+32.9 (${\theta }_E\sim 43^{\prime \prime }$)
• GLEAM: Galaxy Line Emission & Absorption Modeling
• Deep Extragalactic VIsible Legacy Survey (DEVILS): First Data Release Covering The D10 (COSMOS) Region
• A new quasar strongly-lensed candidate by the galaxy cluster WHJ0400-27 with a $18^{\prime \prime }$ image-separation
• Distant clusters of galaxies in the 2XMM/SDSS footprint: follow-up observations with the LBT
• Two spectroscopically confirmed galaxy structures at z=0.61 and 0.74 in the CFHTLS Deep~3 field
• Galaxies at the edges: a complete census of MACS J0416.1-2403 cluster