The new data release from the Gaia-ESO Public Spectroscopic Survey (GES) DR4 delivers about 190,000 stacked, quality-controlled, 1-d spectra (R between 18000 and 54000) of 114,500 unique stellar targets. These stars were observed with GIRAFFE and UVES from 31.12.2011 to 26.01.2018, during the entire time execution of the survey. These targets were selected from all the major structural components of the Milky Way: bulge, thick and thin discs, halo, including open star clusters of all ages and masses. The 1-D spectra from GES DR4 augment or update the spectra published in the previous data releases, which included observations up to July 2014 (~44000 spectra for ~25000 objects).

A catalog of radial velocities is being finalized and will be released in the subsequent data release (DR4.1), together with the 1D stacked spectra for additional ~600 unique targets.

The final data release from the Gaia-ESO survey containing the catalog with the measured stellar parameters will be released in May 2022.

The total volume of GES DR4 is 32 GB. These data are available via the Science Portal, and programmatically. More information is available in the accompanying release documentation. Instructions on how to read or display data in the ESO Science Data Products tabular data format can be found in the 1D spectrum data format help page.

Related external resources:

• Gaia-ESO home page