VIPERS

VIPERS
Name	VIPERS
Country	France/Italy
Institution	Institut d'Astrophysique de Paris; Istituto Nazionale di Astrofisica
Status	Completed
Wavelength	Optical
Survey area	24 deg²
Redshift range	0.5–1.2
Instruments	VIMOS
Observing site	Cerro Paranal Observatory

VIPERS

VIPERS was a large redshift survey of galaxies at intermediate cosmological epochs designed to map large-scale structure and probe galaxy evolution. It targeted a dense sample of galaxies in the redshift range 0.5–1.2 using multi-object spectroscopy to measure precise distances, clustering, and dynamics. The project involved collaborations among European institutions and leveraged existing imaging from major surveys to select targets and calibrate measurements.

Overview

VIPERS combined spectroscopic observations with imaging from projects such as CFHT Legacy Survey, VISTA Hemisphere Survey, and ancillary data from GALEX and Spitzer Space Telescope to construct a statistically robust sample. The survey strategy emphasized volume and sampling density to measure the growth rate of structure, baryon acoustic oscillations, and galaxy properties across cosmic time, connecting to analyses from Sloan Digital Sky Survey and high-redshift work by DEEP2 Redshift Survey and zCOSMOS. Management and science coordination included researchers from CEA Saclay, INAF, and the European Southern Observatory network.

Survey Design and Instruments

Target selection relied on photometry from Canada–France–Hawaii Telescope observations and color cuts informed by templates from Bruzual & Charlot models and population synthesis used in COSMOS studies. Spectroscopy was obtained with the VIMOS spectrograph mounted at Very Large Telescope, applying slit-mask designs similar to those used in VVDS and zCOSMOS. Observational planning accounted for visibility at Cerro Paranal Observatory and calibration using standard stars tied to the Landolt photometric system and spectrophotometric standards exploited in ESO pipelines. Instrumental configuration choices echoed methods from 2dF Galaxy Redshift Survey and supported cross-comparisons with WiggleZ Dark Energy Survey results.

Data Processing and Analysis

Raw spectral data were reduced with customized pipelines building on techniques developed for VIPERS PDR predecessors, including bias subtraction, flat-fielding, wavelength calibration using arc lamps like those in ESO calibration suites, and sky subtraction procedures refined in SDSS pipelines. Redshift estimation combined automated cross-correlation algorithms derived from Tonry & Davis methodology and human validation panels modeled on practices at DEEP2 Redshift Survey. Quality flags and completeness masks were produced to enable clustering analyses comparable to those from BOSS and eBOSS. Measurement of velocity dispersions and emission-line fluxes used methods paralleling analyses in GAMA and MaNGA.

Scientific Results

VIPERS delivered constraints on the growth rate of cosmic structure through redshift-space distortion measurements, complementing findings from Planck cosmic microwave background results and distance constraints from Type Ia supernovae programs such as those by the Supernova Legacy Survey. The survey quantified galaxy stellar mass functions and specific star-formation rates, building on mass estimates techniques from SDSS and stellar-population inferences used in DEEP2. Environmental dependence of galaxy properties was assessed with comparisons to local benchmarks like 2MASS and higher-z datasets including COSMOS and UltraVISTA. VIPERS provided measurements of baryon acoustic oscillation signatures at intermediate redshift that interfaced with analyses from BOSS and theoretical predictions from ΛCDM-based simulations run with codes such as GADGET. The project produced catalogs enabling studies of galaxy bias, halo occupation distributions tied to models from Halo Occupation Distribution literature, and tests of modified gravity scenarios discussed alongside results from KiDS and DES.

Data Release and Access

VIPERS data releases included spectroscopic catalogs, photometric cross-matches, redshift quality flags, and value-added products like stellar masses and star-formation rates. Data access mechanisms followed community standards established by archives such as the ESO Science Archive and the Centre de Données astronomiques de Strasbourg, with catalog formats interoperable with tools used in TOPCAT and virtual observatory services promoted by the International Virtual Observatory Alliance. Documentation and data papers provided provenance similar to releases from SDSS and GAMA.

Legacy and Impact

The VIPERS dataset continues to inform studies of galaxy evolution, large-scale structure, and cosmological parameters, serving as a mid-redshift bridge between surveys like SDSS and high-redshift initiatives such as VIMOS Ultra-Deep Survey. Its methodological developments influenced analysis pipelines in subsequent projects including Euclid preparatory work and ground-based spectroscopic efforts tied to 4MOST and DESI planning. VIPERS-trained samples and catalogs remain referenced in follow-up investigations by groups at INAF, Institut d'Astrophysique de Paris, and collaborating institutions across Europe, contributing to ongoing synergies with space missions like Euclid and legacy fields such as COSMOS and CFHTLS.

Category:Galaxy surveys