The formation of stars and planets happens over multiple scales, which can interact. In particular, planet formation happens in the dense, complex environment of star forming regions. This thesis... Show moreThe formation of stars and planets happens over multiple scales, which can interact. In particular, planet formation happens in the dense, complex environment of star forming regions. This thesis primarily explores the effects of high stellar density and presence of nearby massive stars (or a low density and absence of massive stars) on the evolution of protoplanetary disks, and their consequences for planet formation. Additionally, the dynamics of stellar feedback-driven shells is explored, and a novel operator splitting algorithm is introduced that allows for flexible coupling of a large number of physical models. Show less
This thesis focusses on the temperature structure in protoplanetary disks. The relation between structures seen in the dust and gas-phase molecules is investigated. This is crucial to understand... Show moreThis thesis focusses on the temperature structure in protoplanetary disks. The relation between structures seen in the dust and gas-phase molecules is investigated. This is crucial to understand the chemical composition of the planet forming material as well as to quantify the amount of gas present in the disk, a crucial parameter to determine if planets are likely present in the disk. One of the important regions in the disk is the water snowline, the midplane location where water freezes-out onto the dust grains. In this thesis, chemical modelling is used to infer the snowline location in a hot disk. This result is confirmed in the next chapter by 2D imaging of the water snow surface, the 2D equivalent of the water snowline. Additionally, the temperature structure across transition disk cavities is investigated to determine the mass of the planets that may be carving that cavity. Finally, the relation between the structures traced in the gas by different molecules and the dust is investigated to show that the chemical composition at the location of the dust rings and dust trap in the HD 100546 and OPH-IRS 48 disks, respectively, are different than in the other disk regions. Show less
Detecting planets during their formation stages is crucial for understanding the history and diversity of fully developed planetary systems like our own. However, observing young planets directly... Show moreDetecting planets during their formation stages is crucial for understanding the history and diversity of fully developed planetary systems like our own. However, observing young planets directly is challenging because they are often deeply embedded within their host protoplanetary discs, rich in gas and dust. To overcome this limitation, this thesis introduces a novel methodology for identifying coherent kinematic perturbations in discs induced by giant planets orbiting stars with a mass similar to that of the Sun. This approach not only allows us to investigate the presence of planets but also to determine their most likely radial and azimuthal positions in a statistically robust manner. Moreover, it offers the additional benefit of enabling a three-dimensional reconstruction of the physical and dynamical structure of these planet-forming environments by simultaneously modelling the emission of multiple molecular tracers.The methodology is applied to various protoplanetary discs observed using the world-class interferometer ALMA, revealing a wide variety of kinematic and temperature features. These features include large-scale substructures with spiral and ring-like morphologies, as well as localised perturbations, some of which span coherently across the vertical extent of the disc indicating meridional circulation of material. Among the eight discs analysed, five exhibit signatures in the outer regions that could potentially be associated with massive embedded planets, suggesting that the interaction between discs and wide-orbit giant planets may represent a common early mechanism with a fundamental role in shaping the evolution of discs and, as a result, in the assembly and composition of planetary systems. Show less
