Data Release 1: The UVES Spectral Quasar Absorption Database (SQUAD)

Published: 08 Mar 2019
Sky distribution of the 467 DR1 quasars for which final spectra were produced.

The UVES SQUAD DR1 comprises fully reduced, continuum-fitted high-resolution spectra of quasars with redshifts z = 0–5, with the primary goal of enabling statistical studies of large quasar and absorber samples at high resolution. DR1 includes 467 quasar spectra from the Ultraviolet and Visual Echelle Spectrograph (UVES) on the ESO-VLT. These quasars have at least one exposure in the ESO UVES archive (longer than 100 sec) that was observed before 30th June 2008. All exposures longer than 100 sec observed before 17th November 2016 for these quasars were then included in the final, combined spectra in DR1. In total, 3088 exposures were selected and successfully processed, with a total exposure time of 10 million seconds (2803 hrs; an average of 5.9 hrs per quasar).

The spectra are available from the ESO Science Portal or programmatically. More details about the release content can be found in the associated Phase 3 data release description. Ancillary data are provided to allow users to reproduce, or improve, the full data reduction, processing and exposure combination to form the final spectra. The full database description, quasar catalogue, scientific applications of the spectra and a catalogue of the damped Lyman-alpha systems (DLAs) in the DR1 spectra are presented in Murphy et al., 2019, MNRAS, 482, 3458.