Title：The stellar environment’s influence on protoplanetary discs and planet formation

Speaker：Jeremy Lewis Smallwood（ASIAA）

Time：9:30-10:30 am Dec. 22th (Friday)

Tencent Meeting：576-157-8290 password: 6360

Location: Lecture Hall, 3rd floor

Abstract：

Stars in dense clusters often form binary systems, surrounded by circumbinary discs of gas and dust. Misalignments between these discs and the binary orbit are common during stellar evolution, driven by dissipation. My research, utilizing 3D hydrodynamical simulations, focuses on the evolution of highly misaligned circumbinary discs. I demonstrate that polar-aligned circumbinary discs are conducive to the formation of polar circumbinary planets. Additionally, misaligned and polar circumbinary material leads to the formation of circumstellar discs undergoing Kozai-Lidov oscillations, potentially giving rise to the formation of misaligned giant circumstellar planets. Not only can bound binary stars impact protoplanetary disc evolution and planet formation, but unbound perturbers (flybys) can as well. I showcase 3D hydrodynamical simulations of non-grazing and grazing encounters. The flyby perturbs the gas and dust differently, which may enhance planet formation during such encounters. The stellar environment is key to shaping protoplanetary discs and, thus, planet formation.

CV：Dr. Jeremy Smallwood, who earned his Ph.D. in 2021 from the University of Nevada, Las Vegas (UNLV) under Dr. Rebecca Martin's guidance, received the prestigious UNLV Outstanding STEM Dissertation Award for his research on the dynamics of misaligned and distorted discs around binary and higher-order star systems. Jeremy was then awarded the NCTS Prize Fellowship at the National Center for Theoretical Sciences in Taipei, Taiwan, starting in October 2021. Faced with COVID-19-related challenges, his relocation plans became impractical. He secured a temporary postdoctoral scholar position at Baylor University's Center for Astrophysics, Space Physics, and Engineering Research (CASPER), collaborating with Dr. Lorin Matthews on moon-forming impacts. He was then honored with the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) Distinguished Postdoctoral Fellowship in October 2022. As of now, Jeremy has authored a total of 18 publications, 14 of which he served as the first author.