I am Jiaxuan Li 李嘉轩 (pronounced as Lǐ Jiā Xuān ), a graduate student at Department of Astrophysical Sciences, Princeton University.

I'm interested in a variety of topics in astronomy and astrophysics: galaxy formation and evolution, low surface brightness astrophysics, stellar population inference, cosmology, statistical methods and machine learning.

I worked on Hyper Suprime-Camera (HSC) data to study the stellar halo of massive galaxies and intra-cluster lights (ICL). Together with Prof. Alexie Leauthaud (UCSC), Dr. Song Huang (Princeton), Prof. John Moustakas (Siena) and the Dragonfly team, we explored the ability of different sky surveys (HSC, DECaLS, Dragonfly and SDSS) to extract the stellar halo light profiles of massive galaxies. We effectively addressed the major systematic error (sky background subtraction) in measuring the surface brightness profiles. We push the detection limit of HSC to 30 mag per square arcsec in r-band and find good agreement between DECaLS and HSC measurements (less than 0.05 dex difference on stellar mass measurements). Check out our paper: Reaching for the Edge I: Probing the Outskirts of Massive Galaxies with HSC, DECaLS, SDSS, and Dragonfly.

I helped Prof. Pieter van Dokkum (Yale) on developing and maintaining the "Multi-resolution filtering (MRF)" technique (van Dokkum et al. 2019), which is designed to isolate extended low surface brightness emissions in the Dragonfly imaging data. Using this technique, we are aiming to discover unseen low surface brightness objects including ultra-diffuse galaxies, tidal disruption debris and Galactic cirrus in the Dragonfly Wide Field Survey. I'm also working on the Dragonfly images of NGC 1052 field to constrain the total mass of NGC1052-DF2 and DF4, which are believed to be lacking dark matter.

Advised by Prof. Yingjie Peng (KIAA), I utilized MaNGA IFU data and discovered a population of galaxies which have H-alpha ring-like emission structures. We studied their properties and found high bar fraction, high AGN (Seyfert & LINER) fraction and high bulge-to-total ratio. This might support that it is the joint effect of bar, bulge and AGN that quenches the spiral galaxies in an inside-out mode.