Title: Pebble accretion at the origin of water in Europa,
Abstract: Despite the fact that the observed gradient in water content among the
Galilean satellites is globally consistent with a formation in a circum-Jovian
disk on both sides of the snowline, the mechanisms that led to a low water mass
fraction in Europa ($\sim$$8\%$) are not yet understood. Here, we present new
modeling results of solids transport in the circum-Jovian disk accounting for
aerodynamic drag, turbulent diffusion, surface temperature evolution and
sublimation of water ice. We find that the water mass fraction of pebbles
(e.g., solids with sizes of 10$^{-2}$ -- 1 m) as they drift inward is globally
consistent with the current water content of the Galilean system. This opens
the possibility that each satellite could have formed through pebble accretion
within a delimited region whose boundaries were defined by the position of the
snowline. This further implies that the migration of the forming satellites was
tied to the evolution of the snowline so that Europa fully accreted from
partially dehydrated material in the region just inside of the snowline.