Welcome!

I am an NSF Astronomy & Astrophysics Postdoctoral Fellow at Johns Hopkins University. I am a proud member of the Interstellar Medium group based at the Space Telescope Science Institute (STScI, aka "the Tute") in Baltimore, MD. 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.

I like to think about how star-forming material cycles through the local interstellar medium (ISM) in various ionized, dusty, neutral and molecular phases. I am particularly interested in decoding the multi-dimensional structure of the ISM and the nature of gas flows in galaxies.

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 a convolutional neural network trained by synthetic observations of numerical simulations (Murray et al., in prep).

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.