PhD defence
Probing the inner regions
- A.A. Rota
- Date
- Friday 20 February 2026
- Time
- Address
-
Academy Building
Rapenburg 73
2311 GJ Leiden
Supervisor(s)
Summary
The zoo of detected exoplanets highlights the uniqueness of our Solar System and the complexity of planetary system formation, sparking questions about how planetary systems form and evolve. Characterizing these processes is thus essential for understanding the origins of our Solar System. This thesis investigates planet formation from an observational perspective, focusing on protoplanetary disks, the disks of gas and dust that surround forming stars.
Using observations from the ALMA and VLA telescopes, we studied these disks across multiple wavelengths, with a focus on transition disks, which host large dust cavities. We found that the compact emission within the cavity of most transition disks is dominated by free-free emission from ionized gas, associated with jets and/or winds. Moreover, we found a strong correlation between the ionized mass-loss rate, inferred from the free-free emission, and the stellar accretion rate. This suggests that the outflow is connected to the accretion and that accretion in these disks is mainly driven by jets and/or winds. Consistent trends are observed in a sample of full disks, i.e., disks without large cavities.
Among these transition disks, AB Aur stands out as one of the brightest sources of compact emission and shows evidence for a precessing jet, possibly driven by the influence of a companion.
Finally, we investigated the gas and dust structures in three cold transition disks. Contrary to expectations, we found no significant differences in brightness temperature or in gas-to-dust ratio compared to transition disks around more luminous stars, suggesting that parameters other than luminosity regulate the gas temperature structure.
PhD dissertations
Approximately one week after the defence, PhD dissertations by Leiden PhD students are available digitally through the Leiden Repository, that offers free access to these PhD dissertations. Please note that in some cases a dissertation may be under embargo temporarily and access to its full-text version will only be granted later.
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