Proefschrift
Transformation and sublimation of interstellar ices: insights from laboratory experiments and astronomical observations
Stars and planets form within cold, dense clouds of gas and dust drifting through interstellar space. Although dust makes up only a small fraction of this material, it plays a key role in shaping the chemical evolution of these environments.
- Auteur
- J. de Carvalho Santos
- Datum
- 02 juli 2025
- Links
- Thesis in Leiden Repository
On the surfaces of tiny dust grains, smaller than the diameter of a human hair, atoms and molecules freeze out to form interstellar ices and undergo reactions that yield complex molecules, including precursors to life. This thesis explores how these ices evolve across different stages of star and planet formation, combining laboratory experiments and astronomical observations.
In the lab, cryogenic ultra-high vacuum setups were used to simulate and isolate processes such as molecule formation and desorption under interstellar conditions. Experiments focused on key species like methanol (CH3OH) and hydrogen sulfide (H2S), uncovering new reaction pathways and mechanisms for their destruction and desorption. Observational data at radio and infrared wavelengths were used to anchor these findings in real astrophysical environments.
This thesis provides a deeper understanding of how molecules are formed and transformed in ices, and how this chemistry influences the volatile content inherited by comets and planetesimals---helping trace the molecular origins of planetary systems, including our own.