Preview

PDF, English Download (29MB) | Terms of use

Abstract

The Solar System, together with some exoplanetary systems, is known to host multiple planets. These planets are believed to be born in discs composed of gas and dust in rotation around forming stars. These discs are called protoplanetary discs. The formation of such planets is studied via different, complementary, methods: theoretically, with the help of both hydrodynamical simulations to analyse the behavior of the fluids in presence of planets and N-body simulations to predict the dynamical interactions between these planets; and observationally with the recent detailed observations of protoplanetary discs. In this thesis, I use a hydrodynamical approach to investigate the impact of multiple giant planets on the global disc structure. Previous hydrodynamical simulations focus on the local growth of single planets. Here, my collaborators and I start by analysing the impact that a single gas accreting planet has on its surrounding disc at a global scale. I show that the influence of planetary gas accretion on the gas disc structure depends on its viscosity. With that in mind, it is possible, in a second study, to determine how the gas is distributed in a disc hosting two accreting planets. By running long-term hydrodynamical simulations (up to 0.5 Myrs), we find that even if the planets do not start accreting simultaneously, they end up with similar masses. This has an interesting impact on our understanding of planet formation. Finally, an observational approach is investigated by deriving synthetic ALMA images of the potential parental Solar system protoplanetary disc. I use two different simulation codes to determine the behavior of the gas and the dust in presence of multiple giant planets, before relying on a radiative transfer simulation that predicts how light is emitted from the disc. The resulting image is treated to mimic recent protoplanetary disc observations, allowing us to compare the observable features to known discs. With this project, we provide a way to put the Solar system in perspective with the known observed disc. This comparison allows us to better constrain the formation pathway of giant planets. To summarize, this thesis uses a theoretical approach to investigate the formation of multiple giant planets in their protoplanetary disc. I finish by discussing several questions addressed in this work. The answers provided can be used as foundations to follow-up studies, improving our understanding of planet formation both theoretically and observationally.