MPhil Student, Theoretical/Computational Astrophysicist
Welcome to my page
I'm interested in high energy astrophysics and particularly focus on the processes powered by compact objects, such as black hole accretion, jet launching, emission spectra, fundamental plasma physics theory and high energy particle formation. The ultimate goal is to construct better models to improve our understanding of various energetic astrophysical phenomena, e.g. gamma-ray bursts, ultra-luminous X-ray sources, and tidal disruption events.
Currently I am an PhD student working in Dr. Jane Lixin Dai research group at the University of Hong Kong, focusing on the low angular momentum accretion flows and super-Eddington Accretion onto black holes, using state-of-the-art numerical simulations running on large-scale computers.
Black holes are the most compact objects in the Universe, they are dark and invisible. However, when gas falls into black hole, accretion disks can form, gravitational energy turns into heat, and eventually producing bright emissions.
This makes black holes the central engines powering a wide range of luminous phenomena in the universe, such as some X-ray binaries (XRBs) in our Galaxy, active galactic nuclei (AGNs) and long gamma-Ray bursts (GRBs) observed from other galaxies, and very distant quasi-stellar objects (QSOs or quasars) formed in the early Universe.
The accretion process is very complex and stormy, to adress the challenging astrophysical cosmology and astrophysics problems, I do the numerical simulations on supercomputers, using general relativistic magnetohydrodynamics (GRMHD) to model the accretion flows, and perform radiative transfer simulations to reveal light spectra.
The following are some of my on-going projects to understand the mystery of black hole.
Gas accreting onto black hole usually carries angular momentum and forms a disk, the accretion process powers luminous emission, and energetic jet. However, some accreting gas may only carry tiny angular momentum. Can such accretion flow launch a powerful jet?
It is widely believed that some of ultra-luminous X-ray sources (ULXs) could be accreting stellar mass black hole binary systems, where the black hole accretes at super-Eddington rate. This project is intend to be the first systematic studies to understand how the black hole proerpties and the accretion rate of magnetized accretion flows shapes the observation features.
[3] Kwan T. M., Dai L., Tchekhovskoy A. The Effects of Gas Angular Momentum on the Formation of Magnetically Arrested Disks and the Launching of Powerful Jets. The Astrophysical Journal Letters, 2023[ ApJL ] [ ArXiv ]
[2] Yang H., Yuan F., Kwan T. M., Dai L. The properties of wind and jet from a super-Eddington accretion flow around a supermassive black hole. Monthly Notices of the Royal Astronomical Society, 2023[MNRAS] [ ArXiv ]
[1] Thomsen L. L., Kwan T. M., Dai L., Wu S. & Ramirez-Ruiz E. Dynamical unification of tidal disruption events. The Astrophysical Journal Letters, 2022 [ ApJL ] [ ArXiv ]
You shall find the most updated list from NASA NDS