Chan Ho Sang Leon

  • Scholarship in 2023 at University of Colorado-Boulder

About Ho Sang Leon Chan’s work

Ho Sang Leon Chan is an astrophysicist whose research interests are centered on theoretical and computer simulations of accreting black holes.

Recent black-hole images taken by the Event Horizon Telescope (EHT) collaboration offers exciting opportunities to study these exotic objects. More observational data of similar kinds, like OJ 287 and 3C 273, will be available soon. Models of general-relativistic magnetohydrodynamics (GRMHD) simulations and general relativistic ray-tracings (GRRT) of accreting black holes provided by the EHT can match observational images. Still, several unexplained phenomena remain significant gaps in our knowledge of black holes, such as the variability of light curves, the origin of flares, and the physics of radiatively efficient accretion flows. Chan’s research aims to improve our understanding of black holes, through modelling and computer simulations, and to compare them with observational data.

One of his goals is to help develop software that can simulate the radiatively efficient accretion flows around black holes by solving the equations of radiation GRMHD. Radiation GRMHD is a branch of astrophysics that studies the behaviour of plasma (ionized gas), with radiation taken into account, in strong gravitational and magnetic fields, such as those found near black holes.

He also aims to develop non-thermal plasma electron models to understand how electron thermodynamics would affect the accretion flow and electromagnetic observables of accreting black holes. By performing suites of GRRT calculations to generate black-hole images and light curves, Chan hopes to compare numerical models with multiwavelength data, such as those from the EHT, GRAVITY, and Chandra collaboration, and gain a better understanding of the plasma properties around black holes.


Ho Sang Leon Chan completed his BSc in Physics (Enrichment Stream in Theoretical Physics) at the Chinese University of Hong Kong with first-class honours, followed by an MPhil in Physics at the same university. While there, he made the Dean’s Honours List for several years, and was awarded Honours at Entrance. In addition, he was granted several scholarships, such as the Physics Scholarships, the C.W. Chu College’s Foundation Scholarship, the C.W. Chu College's Lee Wai Wing Scholarship, and the Department of Physics Admission Scholarships. One of his previous research paper was featured in AAS Nova. He is currently carrying out his PhD research and studies at JILA and the Department of Astrophysical and Planetary Sciences at the University of Colorado.