Astrochemical Modeling of Star-forming Regions 138 views

Astrochemistry influences various stages of a star’s life cycle, including the star-forming phase, where molecular clouds collapse to form protostars and protostellar disks. This thesis explores the formation and evolution of complex organic molecules (COMs) in both high-mass and low-mass star-forming cores through astrochemical modeling. I investigate extreme methyl formate (MF) to glycolaldehyde (GA) ratios in NGC 6334I, identifying high gas densities and prolonged desorption timescales as the physical cause. To trace ice chemistry evolution from pre-stellar collapse to protostellar disk formation, I present a coupled radiation hydrodynamical and chemical model of a hot corino, comparing column density predictions with JWST and Spitzer observations across different YSO stages. Furthermore, I analyze COM variability in four Class 0 protostars from the CORINOS project, utilizing ALMA observations and radiative transfer modeling. I find that the low-inclination source, Ser-emb 7, exhibits lower observed CH3OH column densities, while ice column densities remain unaffected during Class 0. By integrating astrochemical modeling with observational comparisons, this work addresses key scientific inquiries: the physical conditions and chemical pathways that drive high MF:GA ratios, the impact of viewing angle on observed column densities, and the implications of our models on the inheritance of COMs in solar-type star formation. These findings advance understanding of COM evolution, providing insights into protostellar chemistry and molecular origins.

PHD (Doctor of Philosophy)

English

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2025-04-29