First data release of VANDELS: a deep VIMOS ESO Public Survey of the CANDELS UDS and CDFS fields

Published: 29 Sep 2017

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 numbers: 194.A-2003(E-K) ).The data release includes spectra for all galaxies whose observing time was completed. Furthermore, VANDELS DR1 includes the spectra for those galaxies whose observing time reached 50% of the total integration time , i.e. 20 out of 40 total hours and 40 out of 80 total hours.
The number of spectra released is 879, 415 in CDFS and 464 in UDS,  and 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.