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

TL;DR

<p>We present the final data release of the VIMOS VLT Deep Survey (VVDS), delivering a purely i-band selected spectroscopic sample of 35,016 extragalactic objects with redshifts up to $z\sim6.7$ across $0.142\leq {\rm area} \leq 8.7$ deg$^{2}$. The survey combines Wide, Deep, and Ultra-Deep components, uses long integrations and broad wavelength coverage ($3650\leq \lambda \leq 9350$ Å) to cross the redshift deserts, and employs a probabilistic redshift reliability flag system calibrated by independent reobservations. A rigorous selection-function framework (TSR, SSR, PSR) and detailed completeness corrections enable robust, volume-limited analyses; the data set includes detailed multi-wavelength coverage and comprehensive data products. The VVDS data release provides a foundational resource for studying galaxy and AGN evolution over more than 12 Gyr of cosmic time, with broad applicability to large-scale structure, luminosity functions, and high-redshift populations such as Ly$\alpha$ emitters.</p>

Abstract

We describe the completed VIMOS VLT Deep Survey, and the final data release of 35016 galaxies and type-I AGN with measured spectroscopic redshifts up to redshift z~6.7, in areas 0.142 to 8.7 square degrees, and volumes from 0.5x10^6 to 2x10^7h^-3Mpc^3. We have selected samples of galaxies based solely on their i-band magnitude reaching i_{AB}=24.75. Spectra have been obtained with VIMOS on the ESO-VLT, integrating 0.75h, 4.5h and 18h for the Wide, Deep, and Ultra-Deep nested surveys. A total of 1263 galaxies have been re-observed independently within the VVDS, and from the VIPERS and MASSIV surveys. They are used to establish the redshift measurements reliability, to assess completeness, and to provide a weighting scheme taking into account the survey selection function. We describe the main properties of the VVDS samples, and the VVDS is compared to other spectroscopic surveys. In total we have obtained spectroscopic redshifts for 34594 galaxies, 422 type-I AGN, and 12430 Galactic stars. The survey has enabled to identify galaxies up to very high redshifts with 4669 redshifts in 1<=z_{spec}<=2, 561 in 2<=z_{spec}<=3 and 468 with z_{spec}>3, and specific populations like LAE have been identified out to z=6.62. We show that the VVDS occupies a unique place in the parameter space defined by area, depth, redshift coverage, and number of spectra. The VVDS provides a comprehensive survey of the distant universe, covering all epochs since z, or more than 12 Gyr of cosmic time, with a uniform selection, the largest such sample to date. A wealth of science results derived from the VVDS have shed new light on the evolution of galaxies and AGN, and their distribution in space, over this large cosmic time. A final public release of the complete VVDS spectroscopic redshift sample is available at http://cesam.lam.fr/vvds.

Figures (26)

• Figure 1: The redshift distributions from the 35 016 galaxies in the VVDS surveys: 25 805 galaxies in the VVDS-Wide (including 3 768 from the VVDS-Deep satisfying the $17.5 \leq I_{AB} \leq 22.5$ selection), 11 486 galaxies in the VVDS-Deep, 721 galaxies in the VVDS-UltraDeep (excluding those re-observed from the VVDS-Deep), and 217 Lyman-$\alpha$ emmitters (133 found serendipitously, the other galaxies coming from the Deep and Ultra-Deep samples). The redshift distribution of the 422 type-I AGN found in the VVDS surveys is shown on the top panel.
• Figure 2: Sky background subtraction accuracy expressed as the ratio of the sky subtracted spectrum over the observed sky spectrum, obtained from the 18h stack of VIMOS-LRRED observations for the VVDS-UltraDeep survey.
• Figure 3: Comparison of independent redshift measurements and classification of 558 galaxies in VVDS-Wide and in the VIPERS survey (Guzzo et al., 2013). The comparison is made for each of the 4 categories of spectra in the VVDS: flags 1, 2, 3 and 4, and 9. The probability for the redshift of each class of galaxy is computed as the fraction of galaxies which agree between VVDS and VIPERS to $|dz| \leq 0.0025\times(1+z)$, and is indicated in the upper left corner of each panel, using as a reference the most reliable redshift flags from the VIPERS survey (the small histogram inset in each panel shows the VIPERS flag distribution). Using only the most reliable flags, the sigma of the redshift difference between VVDS and VIPERS redshift measurements normalized to the expansion factor (1+z) is $\sigma_{dz}=0.00072$ which translates to an individual redshift measurement uncertainty of $\sigma_v=202$km/s.
• Figure 4: Redshift difference $dz=z_{MASSIV}-z_{VVDS}$ between the independent redshift measurements of the VVDS and MASSIV surveys for 88 galaxies in the VVDS and in the MASSIV survey (Contini et al., 2012). Flags 2 are represented with circles, flags 3 and 4 with squares, and flag 9 with stars. Dashed lines identify $dz=0.0025\times(1+z)$. The sigma of the redshift difference between VVDS and MASSIV redshift measurements normalized to the expansion factor (1+z) is $\sigma_{dz}=0.00072$ which translates to an individual redshift measurement uncertainty of $\sigma_v=153$km/s.
• Figure 5: The distribution in ($\alpha, \delta$) of all galaxies observed in the Deep $17.5 \leq i_{AB} \leq 24$ sample. Epoch 1 observations are indicated in black heavy symbols, observations from 8 additional VIMOS pointings are indicated in blue, and the photometric parent sample as dots.