My research focuses on dwarf galaxies and the connection between the galaxies and their host dark matter halos. I combine theoretical models, numerical simulations, and astronomical survey data to study dwarf galaxies and the galaxy–halo connection, answering questions about the nature of dark matter, galaxy formation physics, and the uniqueness of our own Milky Way.
Below I detail the areas of my research interest, with links to associated papers. I also list the science collaborations that I have participated in and my contributions. You can also find a full list of my publications on my Publications page.
Areas of Interest
- Galaxy assembly bias and secondary halo biases: to understand how halo clustering [ref:1,2] and galaxy clustering [ref:1,2,3,4,5] depend on the halo formation history and other secondary properties; and to identify novel probes to constrain assembly bias [ref].
- Satellite galaxies in the Milky Way and beyond: to explore the abundance and properties of the satellite galaxies in the Milky Way and beyond [ref:1,2,3,4], and to compare them with theoretical predictions [ref:1,2,3,4,5,6].
- Dark matter substructures and halo structure: to explore how dark matter substructures affect their host halo structure [ref:1,2], and what properties of the host halos affect the abundance of dark substructures [ref:1,2,3], and to provide predictions for observations of dark substructures, both for the LCDM case [ref] and for SIDM [ref].
- Galaxy dynamics at small scales: to predict small-scale galaxy properties/dynamics using gravity-only simulations and galaxy-halo connection models and compare with observation [ref:1,2].
- Zoom-in dark matter simulations: to better understand the variance in various halo properties by analyzing a statistical sample of zoom-in isolated halos in LCDM [ref:1,2,3] and also for SIDM [ref].
- Local velocity distribution function (VDF) of dark matter: to find an accurate VDF model [ref], which is crucial to dark matter direct detection experiments, especially for low-mass dark matter candidates [ref].
I participate in many collaborative projects, including:
- Satellites Around Galactic Analogs (SAGA): A spectroscopic survey that searches for dwarf galaxies around nearby Milky Way-like galaxies to obtain satellite luminosity functions of these systems, which enable us to learn more about the nature of dark matter and galaxy formation physics [ref:1,2].
- Rubin Observatory LSST Dark Energy Science Collaboration (DESC): I serve as a Dark Matter Working Group co-convener and a Data Access Team lead in the DESC. I contribute to the validation and data access effort for the DESC Data Challenge 2 (DC2), including the cosmoDC2 synthetic galaxy catalog and the simulated sky survey. Selected DC2 data sets are publicly available at the DESC Data Portal, which I help develop. I led the development of the DESCQA validaton framework [ref] and the Generic Catalog Reader that provides an unifed data access interface. I helped form the Dark Matter Working Group in the DESC in 2019. I was credited the Builder Status by the DESC in 2019.
- Rubin Observatory LSST Dark Matter Group: a community effort to explore how observations from the LSST can act as novel probes to provide constraints on the fundamental nature of dark matter [ref]. As of 2020, most activities have been taking place in the Dark Matter Working Group in the DESC.
- Southern Stellar Stream Spectroscopic Survey (S5): A spectroscopic survey that maps the kinematics and chemistry of stellar streams in the Southern Hemisphere. I coordinate an auxiliary science case on finding low-redshift galaxies [ref].
- DECam Local Volume Exploration Survey (DELVE): a survey program to study dwarf galaxies in the Local Volume by imaging the entire southern sky with DECam [ref].
- Magellanic Satellites Survey (MagLiteS): a NOAO community survey that uses DECam to explore the neighborhood of the Magellanic system [ref].
- Dark Energy Survey (DES): In 2015, I helped analyzing the anisotopic spacial distribution of the newly discovered Milky Way satellite candidates [ref]. More recently, as an external collaborator, I participated in the theoretical analysis of all Milky Way satellites discovered to date [ref].
- Dark Energy Spectroscopic Instrument (DESI): In 2019 I participated in a study of DESI-like LRG clustering [ref]. And, while not as part of a DESI project, I developed the DECaLS Image List Tool to display image cutouts retrieved from the Dark Energy Camera Legacy Surveys.
- The Aemulus Project: A set of simulations to builds emulators for precision cosmology [ref:1,2,3].
- Sussing Merger Trees: a series of comparison among different merger tree building codes [ref].
- One Dark Matter Profile Please, Hold the Subhaloes [astrobites 2020/07]
- The Milky Way’s satellites help reveal link between dark matter halos and galaxy formation [SLAC News, Phys.org etc. 2020/03]
- Is the Milky Way an 'outlier' galaxy? Studying its 'siblings' for clues [Yale News, 2017/09]
- Standard Model of the Universe Withstands Most Precise Test by Dark Energy Survey [SLAC News 2017/08]
- Building Halos by Digesting Satellites [AAS NOVA, 2016/05]
- Stanford physicists help discover hidden dwarf dark galaxy [Stanford News, 2016/04]
- Learning about the future from the distant past [Stanford News, 2016/03]
- Dark Energy Survey finds more celestial neighbors [Fermilab News, 2015/08]
- Scientists find rare dwarf satellite galaxy candidates in Dark Energy Survey data [Fermilab News, 2015/03]
- KIPAC Theorists Weigh In on Where to Hunt Dark Matter [SLAC News, 2013/05]
- Hints of lightweight dark matter get even stronger [New Scientist, 2013/05]
- Learning to play the dark matter boogie [Symmetry Magazine, 2012/10]
When I was an undergrad, I had been working on many different topics, including: