About me

My name is Shuo Xu （许朔）, a PhD student in the Department of Astronomy at Tsinghua University. I work on galaxy astrophysics, focusing on the connection between massive galaxies and their dark matter halos.

The extended stellar envelopes of massive galaxies are built largely from accreted stars, so they preserve a memory of how their host halos were assembled. Using the Illustris and IllustrisTNG cosmological simulations, I study how to read this memory and how to turn it into practical tools for observational cosmology. In a series of papers, I have shown that the outskirt stellar mass of massive galaxies is an excellent proxy for halo mass, that halo assembly history systematically biases observable mass tracers such as optical richness, and that the stellar distribution of massive galaxies retains a “fossil record” of the assembly history of their host halos. These results have direct implications for calibrating cluster mass proxies in ongoing and upcoming surveys such as HSC, Euclid, Rubin/LSST, and DESI.

More broadly, I am interested in galaxy formation, galaxy and halo assembly bias, gravitational lensing and dark matter physics.

You can reach me at xus21[at]mails.tsinghua.edu.cn.