VANDELS Public Spectroscopic Survey: First Data Release

Published: 05 Oct 2017
VANDELS: Example of VIMOS pointings within the UDS field

VANDELS is a deep Public Spectroscopic Survey of high-redshift galaxies with the VIMOS spectrograph. It is designed to exploit the multi-wavelength imaging and near-IR grism spectroscopy available in the CANDELS UDS and CDFS fields. The goal is to obtain spectra with sufficient signal-to-noise ratio to derive metallicities and velocity offsets from absorption and emission lines, allowing a detailed investigation of the physics of galaxies in the early Universe. Within an area of 0.2 deg2, the survey will deliver more than 2500 high (15-20) signal-to-noise spectra of star forming galaxies in the redshift range 2.5 < z< 5.5, passive galaxies with H< 22.5 at 1.5 < z < 2.5, and star forming galaxies at 3.0 < z < 7.0 with H < 27, in the AB magnitude system.

The first data release (DR1) is based on the observations carried out from August 2015 until January 2016 (ESO run IDs: 194.A-2003[E-K]).The data release includes spectra for all galaxies whose observing time was completed as well as those galaxies whose observing time reached 50% of the total integration time (i.e., 20/40 and 40/80 total hours). The number of spectra released is 879, of which 415 are in CDFS and 464 are in UDS; the total data volume is 461 MB.

The VANDELS DR1 includes:
Fully wavelength- and flux-calibrated 1D spectra for 879 distinct galaxies, along with the associated error spectrum and sky spectrum;
• The associated wavelength-calibrated 2D spectra for 879 distinct galaxies;
• A catalogue with the essential galaxy parameters.

The VANDELS public survey data release DR1 is accompanied by a comprehensive description of the spectra and catalogue. Instructions on how to read or display data in the ESO/SDP tabular data format can be found in the 1D spectrum data format help page.

Upper image: Example of VIMOS pointings within the UDS field from the ESO Phase 3 data release description.