ABSTRACT
Circumstellar disks as young as 0.5 Myr bear gaps and rings as tentative planet signposts, which aligns with accumulating evidence of early planet formation. However, such young disks are poorly understood both observationally and theoretically. They are likely affected by the star formation environment becoming warped or eccentric. The disk flow can become peculiar, and various instabilities follow, alternating subsequent planet formation processes. We will discuss if and how a distorted disk can restore a coplanar circular configuration. On the other hand, early disks are relatively massive and subject to gravitational instability, thus developing spiral density waves. We will show that spirals can drive a large-scale dynamo, leading to magnetic fields with nearly thermal amplitudes, even in poorly ionized disks. The strong fields further control disk fragmentation, allowing the top-down formation of giant planets as light as Neptune. Finally, young disks can interact with each other and form a population of free-floating planetary mass objects, including wide-orbit Jupiter mass binaries.
BIO
Dr. Deng is an Associate Professor at the Shanghai Astronomical Observatory, Chinese Academy of Sciences. Before that, He was a postdoc at the Department of Applied Mathematics and Theoretical Physics, University of Cambridge (2019-2021), supported by an SNSF postdoc mobility fellowship. He obtained his PhD in Astrophysics from the University of Zurich (2015-2019) and a BS in physics from Tsinghua University (2010-2014).
Host: Wei Zhu
