I am an assistant astronomer at the Space Telescope Science Institute (STScI, aka "the Tute") in Baltimore, MD, where I am a proud member of the ISM* group. I recieved a B.A. in Physics & Astronomy at Carleton College in 2011, and a Ph.D. from the Department of Astronomy at the University of Wisconsin-Madison in 2017.

Research Interests

Galaxy evolution is driven by where, when and how stars form. In particular, the flow of material through the interstellar medium (ISM) -- from diffuse plasma to molecular, star-forming clouds -- is crucial. I use sensitive radio observations of neutral hydrogen (HI) and molecular gas to trace this flow in the Galactic and Magellanic ISM.

Scylla: a multi-headed attack on dust evolution and star formation

I am the PI of Scylla: a 500-orbit Hubble Space Telescope (HST) parallel imaging program (Cycles 27-29) to complement the HST Ultraviolet (UV) Legacy library of Young Stars as Essential Standards (ULLYSES) survey. We will: (1) map the extinction curve and dust grain properties at high resolution in a diverse range of interstellar conditions; (2) constrain the multi-dimensional structure of gas in the Large and Small Magellanic Clouds; and (3) measure the comprehensive star formation and chemical enrichment histories of nearby dwarf galaxies.

The nature and distribution of cold, optically-thick HI

Based on a large sample of 21 cm absorption lines, I found that optically-thick HI does not dominate the "dark" gas mass budget in the local ISM , rather it is a combination of intrinsic variations in dust grain emissivity and H2 undetected by standard tracers. Using machine learning techniques, I plan to characterize the nature of cold, optically-thick HI on large scales. Above is an all-Northern sky map of the cold neutral medium, derived from the first convolutional neural network applied to diffuse gas in the local ISM..

Unexpectedly warm neutral medium

I detected absorption by the warm neutral medium (WNM) with unexpectedly high excitation temperature , indicating that Lyman-alpha scattering is important for HI excitation, with consequences for disentangling astrophysical effects from HI signals throughout cosmic time.