The Gaia-ESO Survey: Galactic evolution of lithium from iDR6
  We exploit the unique characteristics of a sample of open clusters (OCs) and
field stars for which high-precision 7Li abundances and stellar parameters are
homogeneously derived by the Gaia-ESO Survey (GES). We derive possibly
undepleted 7Li abundances for 26 OCs and star forming regions with ages from
young to old spanning a large range of Galactocentric distances, which allows
us to reconstruct the local late Galactic evolution of lithium as well as its
current abundance gradient along the disc. Field stars are added to look
further back in time and to constrain 7Li evolution in other Galactic
components. The data are then compared to theoretical tracks from chemical
evolution models that implement different 7Li forges. We find that the upper
envelope of the 7Li abundances measured in field stars of nearly solar
metallicities traces very well the level of lithium enrichment attained by the
ISM as inferred from observations of cluster stars. We confirm previous
findings that the abundance of 7Li in the solar neighbourhood does not decrease
at supersolar metallicity. The comparison of the data with the chemical
evolution model predictions favours a scenario in which the majority of the 7Li
abundance in meteorites comes from novae. Current data also seem to suggest
that the nova rate flattens out at later times. This requirement might have
implications for the masses of the white dwarf nova progenitors and deserves
further investigation. Neutrino-induced reactions taking place in core-collapse
supernovae also produce some fresh lithium. This likely makes a negligible
contribution to the meteoritic abundance, but could be responsible for a mild
increase of the 7Li abundance in the ISM of low-metallicity systems that would
counterbalance the astration processes.
