This thesis takes steps toward understanding the interaction between gas-phase and solid-state molecules in star- and planet-forming regions. Chapter 1 and 2 provide the reader with an introduction... Show moreThis thesis takes steps toward understanding the interaction between gas-phase and solid-state molecules in star- and planet-forming regions. Chapter 1 and 2 provide the reader with an introduction and in-depth description of methods used in subsequent chapters. Chapter 3 and 4 present the spectroscopic infrared characterization of acetaldehyde, dimethyl ether, ethanol, and methyl formate in the solid state, both pure and mixed in astronomically relevant matrices. This characterization will allow for probing of the solid-state organic inventory of star- and planet-forming regions with the upcoming James Webb Space Telescope. Interferometric observations of the protoplanetary disk around TW Hya with the Atacama Large Millimeter/submillimeter Array are presented in Chapter 5. These results hint that the observed gas-phase formaldehyde is formed in the gas phase, contrary to the generally accepted solid-state formation. Chapter 6 provides an insight to the interaction between gas-phase carbon monoxide and solid-state hydroxyl radicals on the surface of vacuum-UV irradiated water ice. Even tough residence times of carbon monoxide are short, they are sufficient to allow reactions with hydroxyl radicals and produce carbon dioxide. This process could explain the lack of gas-phase carbon monoxide in protoplanetary disks and the presence of carbon dioxide mixed in solid-state water. Show less
Le Gal, R.; Öberg, K.I.; Teague, R.; Loomis, R.A.; Law, C.J.; Walsh, C.; ... ; Zhang, K. 2021
The focus of this thesis is how stars like our Sun and planets like Jupiter, Saturn, and Earth are formed. With arrays of radio telescopes, I observed the environments where the first stages of... Show moreThe focus of this thesis is how stars like our Sun and planets like Jupiter, Saturn, and Earth are formed. With arrays of radio telescopes, I observed the environments where the first stages of star and planet formation occur. This thesis focuses on characterizing different components of young protostellar systems, most notably their jets and disks. Using interferometric radio observations with ALMA array, I provided information on key chemical tracers of different components of the protostellar systems. By characterizing the radio signal from young stars with ALMA and VLA interferometers, I was able to disentangle an emission from the jet and the disk. This led to an unexpected development: I was able to compare dust masses of young disks with those of older disks for the first time. By comparing this information with masses of the extrasolar planets detected so far I showed that the solid cores of gas giants must form in the first 0.1 Myr of stellar life. That is an important time constrain, that pushes the onset of planet formation earlier and highlights the importance of characterization of the youngest protostars in understanding the origin of Solar System and Earth. Show less
