Research

My research is primarily centered around our home galaxy, the Milky Way. I study how our galaxy grew and evolved by mapping the furthest outskirts of the Milky Way, and measuring its structure and dynamics on the largest scales. I am also keenly interested in understanding the physical nature of dark matter using astrophysical detectors like stellar streams and dwarf galaxies. I seek answers to these questions primarily by designing, conducting, and analyzing large spectroscopic surveys, from instrumentation to astrophysics.

On this page I briefly summarize the major themes of my research, along with some representative publications that I’ve lead or co-lead. Projects on which I served as an advisor/mentor are highlighted with asterisks.

The Via Project

The Via Project is constructing twin high-resolution multi-object spectrographs for two of the largest telescopes in the world – the Magellan Clay in Chile and the MMT in Arizona – providing all-sky coverage. Our primary goal is to illuminate the true nature of dark matter by measuring the precise velocities of thousands of faint stars in stellar streams and dwarf galaxies. As Deputy Project Scientist, I play a leading role across all parts of the Via collaboration from designing the instrument to developing our scientific results.

The Galactic Outskirts

The furthest stars in the Milky Way – to 100 kiloparsecs and beyond – hold a treasure trove of information about the recent accretion history of our Galaxy, including the outsize perturbations from the in-falling Magellanic Clouds. As a central part of my PhD, I designed and executed a tailor-made spectroscopic survey to obtain detailed measurements of hundreds of these distant stars, building an all-sky dataset to understand the outer galaxy.

The Evolution of the Milky Way

The Gaia space observatory has revolutionized our understanding of the Miky Way with 3D positions, velocities, and low-resolution spectroscopy of millions of stars. I have extensively worked on extracting scientific information from this rich dataset, and using its unprecedented size and fidelity to trace the formation history of our Galaxy.

White Dwarf Stars

White dwarfs (WDs) are compact stellar remnants left behind by all Sun-like stars. They are some of the best laboratories of general relativistic and quantum mechanical effects on macroscopic scales. As an undergraduate at Johns Hopkins, I helped establish a WD research group with Nadia Zakamska, and have continued to mentor students on a variety of projects related to white dwarf physics and double white dwarf binaries.