Associate Astronomer
Space Telescope Science Institute · ISM* Group
I study the interstellar medium (ISM) at the onset of star formation. By combining spectroscopic and photometric surveys spanning radio through ultraviolet wavelengths, I map the 3D structure, kinematics, and physical properties of the diffuse ISM in the Milky Way and nearby galaxies.
Using deep photometry of millions of resolved stars from space-based surveys of nearby galaxies, spanning the infrared (IR) through UV, my group resolves the ~parsec-scale structure of the ISM via its embedded dust content, completely independently of the systematics associated with standard emission tracers. I am the PI of Scylla: a 350-orbit panchromatic Hubble Space Telescope imaging survey of the Magellanic Clouds, and a leading member of ongoing and upcoming Local Group surveys with HST, JWST and Roman. My goals are to: (1) map dust extinction and grain properties at high resolution across diverse interstellar conditions; (2) constrain the multi-dimensional structure of dust in the Large and Small Magellanic Clouds; and (3) measure the comprehensive star formation and chemical enrichment histories of nearby galaxies.
I combine multi-wavelength surveys to infer the 3D structure and kinematics of the ISM in the Milky Way and nearby galaxies. Recently, I used young, massive stars to trace the line of sight structure of dust in the Small Magellanic Cloud — one of our nearest neighbors and key laboratory for ISM physics — and found that the galaxy is forming stars in two separate systems eclipsed along our line of sight. I am currently leveraging high-resolution 3D dust maps to resolve the distance to HI clouds in the Local Bubble and infer its kinematic properties on large scales for the first time.
I build advanced algorithms to extract the thermal properties of the diffuse, neutral ISM at the onset of star formation. For my PhD, I led 21-SPONGE, the largest, most sensitive survey of Galactic HI absorption at the Karl G. Jansky Very Large Array (VLA). I detected absorption by the warm neutral medium (WNM) with an unexpectedly high temperature, showed that optically-thick HI does not dominate the "dark" gas in the local ISM, and found that the dust to gas ratio varies significantly between warm and cold neutral media. I am interested in applying machine learning methods to next-generation HI surveys to extract full phase information from the cold, warm and unstable neutral media.