How fast do Jupiters grow? Signatures of the snowline and growth rate in the distribution of gas giant planets

We present here observational evidence that the snowline plays a significant role in the formation and evolution of gas giant planets. When considering the population of observed exoplanets, we find a boundary in mass-semimajor axis space that suggests that planets are preferentially found beyond the snowline prior to undergoing gap-opening inward migration and associated gas accretion. This is consistent with theoretical models suggesting that sudden changes in opacity – as would occur at the snowline – can influence core migration. Furthermore, population synthesis modelling suggests that this boundary implies that gas giant planets accrete ∼70 per cent of the inward flowing gas, allowing ∼30 per cent through to the inner disc. This is qualitatively consistent with observations of transition discs suggesting the presence of inner holes, despite there being ongoing gas accretion.