Painting a portrait of the Galactic disc with its stellar clusters
  The large astrometric and photometric survey performed by the Gaia mission
allows for a panoptic view of the Galactic disc and in its stellar cluster
population. Hundreds of clusters were only discovered after the latest G data
release (DR2) and have yet to be characterised. Here we make use of the deep
and homogeneous Gaia photometry down to G=18 to estimate the distance, age, and
interstellar reddening for about 2000 clusters identified with Gaia~DR2
astrometry. We use these objects to study the structure and evolution of the
Galactic disc. We rely on a set of objects with well-determined parameters in
the literature to train an artificial neural network to estimate parameters
from the Gaia photometry of cluster members and their mean parallax. We obtain
reliable parameters for 1867 clusters. Our new homogeneous catalogue confirms
the relative lack of old clusters in the inner disc (with a few notable
exceptions). We also quantify and discuss the variation of scale height with
cluster age, and detect the Galactic warp in the distribution of old clusters.
This work results in a large and homogenous cluster catalogue. However, the
present sample is still unable to trace the Outer spiral arm of the Milky Way,
which indicates that the outer disc cluster census might still be incomplete.
