Speaker: Julia Roquette (University of Geneva)

Date: 9 January 2024

Time: 15:00

Location: Mott lecture theatre

From Spin Evolution to Big Data: A Dual Journey into the Evolution of Young Stellar Objects

In this talk, I will introduce two branches of research focused on the evolution of Young Stellar Objects. The first one follows the spin evolution of these forming stars. While most spin evolution models consider stars that form and evolve in isolation, the vast majority of observed young stars are located in clustered environments. To reduce this discrepancy, we propose a spin evolution modelling approach that considers the influence of open clusters' early environments on the spin evolution of low-mass stars. In particular, we looked at how stellar density and the presence of massive stars shape the local far-ultraviolet radiation fields of clusters, influencing the dissipation timescales of circumstellar disks due to external photoevaporation. Environmentally dependent disk-dissipation timescales directly impact the duration of the star-disk-interaction phase, during which stars are expected to exchange angular momentum with their disk. By modelling the spin evolution of the low mass population of entire clusters with diverse environments, we illustrate how these environments can contribute to shaping clusters' rotational distributions, with the feedback from massive stars playing a crucial role in explaining the mass dependence of rotation observed in the period-mass distributions of observed young regions. In the second part of the talk, I will change gears and talk about our ongoing H2020 project NEMESIS (Novel Evolutionary Model For the Early Stages of Stars with Intelligent Systems), which has been combining Big Data and Machine Learning to revisit and improve our understanding of the evolution of Young Stellar Objects.