The escape of the atmosphere plays a crucial role in planetary evolution. Recent advancements in high spectral resolution transmission spectrum observation have provided an exceptional opportunity to investigate the structure of exoplanet upper atmospheres and their escape processes. In this talk, I will introduce a sophisticated forward model by expanding the capability of a one-dimensional model of the upper atmosphere and hydrodynamic escape, to include important processes of atomic metal species.
Using this model, we can interpret the detected atomic features in the transmission spectrum of WASP-121b, which originate from material outside the planet's Roche lobe. By studying these atomic signatures, we can explore the impact of metals and excited hydrogen on the upper atmosphere, gain insights into the mechanisms of atmospheric escape, and emphasize the significance of the high mass-loss rate caused by Roche lobe overflow.

BIO
Dr. Chenliang Huang earned B.S. in Physics from Peking University in 2011 and completed Ph.D. in Astronomy at the University of Virginia in 2017. Following his doctoral studies, he served as a postdoctoral researcher at the University of Nevada, Las Vegas from 2017 to 2019 and at the Lunar and Planetary Laboratory, University of Arizona from 2019 to 2022. Since 2023, he has been an Associate Research Professor at the Shanghai Astronomical Observatory. His research interests encompass the investigation of the upper atmospheres of gas giant exoplanets, the internal structure of terrestrial exoplanets, and radiative transfer within interacting supernova remnants.