Complex Organic Molecules (COMs) have been detected in objects across different stages of stellar evolution. Many of these COMs are expected to form on interstellar ice and transfer later to the... Show moreComplex Organic Molecules (COMs) have been detected in objects across different stages of stellar evolution. Many of these COMs are expected to form on interstellar ice and transfer later to the gas phase. However, due to the challenge of detecting and assigning molecules in interstellar ice observations, the only frozen COM that has been unambiguously identified is methanol. This scenario is about to change, as the exceptional capabilities of the James Webb Space Telescope (JWST) enable the observation of weak signatures of molecules in interstellar ice.This thesis has a main focus on laboratory studies to support interstellar ice observation with the JWST. The results of the spectroscopic characterization of three COMs, acetone, methylamine, and methyl cyanide mixed in interstellar ice analogs are presented in Chapters 3, 4, and 5, respectively. The potential of their absorption features to trace these species in JWST observations is also discussed. Chapter 6 presents a new experimental approach to studying morphological changes in frozen CO, which is important to understand its morphology in space. Chapter 7 presents a computational study that simulates the infrared spectra of small fullerenes (between 44-70 C atoms) and provides insights for future JWST searches for these molecules Show less
This thesis is largely an experimental study on the formation of solid-state simple and complex organic molecules in the H2O-rich and CO-rich ice phases of dense interstellar clouds and dark cores.... Show moreThis thesis is largely an experimental study on the formation of solid-state simple and complex organic molecules in the H2O-rich and CO-rich ice phases of dense interstellar clouds and dark cores. Astronomical ice observations are also presented and are strongly linked to the experimental work. For decades, it has been realized that particularly complex organic molecules can be formed at extremely low temperatures with the aid of 'energetic' particles, such as UV photons. In this thesis, it is clearly shown that complex organic molecules can also be formed without 'energetic' particles. The experimental laboratory work is supported by computational calculations to constrain which molecules are more or less likely to form under the extreme conditions of interstellar clouds. Show less
