Planets are formed in disks of gas and dust around young stars. These planet-forming disks undergo several physical and chemical processes that can lead to planetary systems like our own. This... Show morePlanets are formed in disks of gas and dust around young stars. These planet-forming disks undergo several physical and chemical processes that can lead to planetary systems like our own. This thesis uses data of two well known planet-forming disks around TW Hya and HD 163296 taken with the Atacama Large (sub)Milimeter Array (ALMA) and the Herschel Space Telescope to study the spatial distribution of their dust and gas content. In particular, we aim to constrain the spatial distribution of the main oxygen- and nitrogen-bearing species in planet-forming disks and to explore the relationship between their physical features and the formation and chemistry of common molecular species. By analysing water and ammonia emission form the disk around TW Hya, we conclude that the location of oxygen- and nitrogen-bearing volatiles in planet-forming disks are set by grain evolution, in particular radial drift. In addition, we conclude that the spatial location of temperature-sensitive species trace substructures in the temperature profile of protoplanetary disks and therefore (indirectly) the impact of dust evolution process on its morphology. Show less
In this thesis chemical and physical processes in the ice mantles on interstellar dust grains are studied. With the Atacama Large Millimetre/submillimetre Array molecules of interest to the... Show moreIn this thesis chemical and physical processes in the ice mantles on interstellar dust grains are studied. With the Atacama Large Millimetre/submillimetre Array molecules of interest to the formation of bigger, life-bearing molecules are detected for the first time around the sun-like low-mass protostar IRAS 16293-2422. These detections give clues about the earliest conditions our solar system formed under and potentially how life on earth emerged. Laboratory studies investigate the formation of these complex species in a laboratory set-up mimicking the conditions on interstellar icy dust grains. In this ways formation routes for molecules with a so-called amide functional group are mapped. Show less
Multiple stars, that is two or more stars composing a gravitationally bound system, are common in the universe.They are the cause of many interesting phenomena, from supernovae and planetary... Show moreMultiple stars, that is two or more stars composing a gravitationally bound system, are common in the universe.They are the cause of many interesting phenomena, from supernovae and planetary nebulae, to binary black hole mergers. Observations of main sequence stars, young stars and forming protostars show that multiplicity is common, and that multiple stars are born. This thesis focuses on several of the open questions on the formation and evolution of multiple stars, namely when do rotationally supported disks form, the factors leading to fragmentation of the cloud core and the physico-chemical structure of multiple protostars. For this purpose, radio interferometric observations of dust continuum and molecular line emission, coupled with chemical and physical models are used to study several young, deeply embedded prototstars. The results of this thesis contribute useful pieces to the puzzle of multiple star formation, demonstrating that rotationally supported disks can form early in the star formation process, while temperature and the presence of disks can alter the physico-chemical protostellar structure. Furthermore, the results of this thesis indicate that mass, rather than temperature, could be an important factor in fragmentation of cloud cores, and the formation of multiple stars. Show less
Polycyclic aromatic hydrocarbons (PAHs) are the most abundant class of organic compounds in space. The PAH field evolves from the constant interaction between experimentalists, theorists,... Show morePolycyclic aromatic hydrocarbons (PAHs) are the most abundant class of organic compounds in space. The PAH field evolves from the constant interaction between experimentalists, theorists, modellers and observers. While laboratory research and quantum chemical calculations together set up the molecular properties of PAH species, astronomers on the other hand, retrieve as much information as possible from the space observations. Nowadays, the PAH field is advanced enough to start implementing all these results into astronomical models, in order to study PAHs from a molecular groundwork. In this regard, the research projects presented in this thesis do precisely that. They constitute a first attempt to gather the vast current knowledge available on specific PAH molecules (not using generic properties), and put it in an astrophysical context, and with it, target some of the key subjects of the field such as: the existence of the so-called grandPAHs in space; the role of PAHs in the formation of molecular hydrogen in photodissociation regions; the abundance of superhydrogenated PAHs and their contribution as a carrier of the 3.4 micron band observed in photodissociation regions; and the deuterium fractionation in PAHs, and their consequent role in explaining the observed deuterium abundance in the local interstellar medium. Show less