I am an Associate Astronomer at the Space Telescope Science Institute in Baltimore, Maryland. As the Mission Scientist for the Nancy Grace Roman Space Telescope, I provide scientific leadership for the Institute’s Roman Space Telescope science operations development effort. In my scientific research, I reconstruct the history of nearby galaxies by studying their resolved stellar populations. I use optical spectroscopy with large ground-based telescopes and ultraviolet through near-infrared imaging with the Hubble Space Telescope to study the stellar dynamics, chemical abundances, and star formation histories of nearby galaxies. I then compare these detailed observations with predictions from simulations of galaxy formation and evolution to infer the merger history of galaxies in the local universe.

My Publications

For an up to date list of refereed and non-refereed publications, visit ADS:


A Little Bit More About Me

I began studying physics and astronomy at The Ohio State University, where I got my undergraduate degree, researched AGN, rooted for the Buckeyes at the Horseshoe, and learned to rock climb at the Red River Gorge in Kentucky.

I did my graduate studies in astronomy and astrophysics in the midst of the beautiful redwood forest that is the campus of the University of California, Santa Cruz. In Santa Cruz I studied the stellar halo of our neighbor, the Andromeda galaxy, using Keck Observatory in Hawaii to take spectra of individual Andromeda stars. I also developed a fondness for banana slugs, trail running in a redwood forest, and skiing at Lake Tahoe.

I was a Hubble Fellow in the astronomy department at the University of Washington working on the ANGST and ANGRRR surveys. I studied the resolved stellar populations of galaxies in the nearby universe using data from the Hubble Space Telescope. I discovered the joys of getting out and away from the crowds while backpacking, and skied as much as possible during five of the heaviest snow years on record.

As an Associate Astronomer at the Space Telescope Science Institute, I support the development of future space observatories, focusing on how to maximize the science that can be achieved with these observatories. I currently serve as the Mission Scientist for the Nancy Grace Roman Space Telescope. The Roman Space Telescope is in development for a launch in the mid 2020s, and will fly a Wide Field Instrument with a field of view 100 times that of Hubble, as well as a powerful Coronagraph Instrument. STScI will be the Science Operations Center for the Roman Space Telescope. I previously worked on the James Webb Space Telescope as part of STScI's NIRSpec instrument team. NIRSpec is an infrared spectrograph with long slit, IFU, and multi-object capabilities . On the research front, I continue to expand my studies of the stellar populations of the Andromeda Galaxy, its environs, and its satellites, as well as dwarf galaxies in the Local Volume.