We have moved from asking What is in the universe? to How did the those things come to be?
I try to answer this question by examining the diffuse phase of the universe. The story of every object in the universe can be simply told as "diffuse material became dense under the influence of gravity". My work aims to understand the flow of this diffuse material. To do this I use spectroscopic measurements of gas (chiefly the 21-cm line) as well as observations of the effects of dust obscuration. The spectroscopy helps me better understand the velocities of gas; the dust helps me understand where the enriched material is in our universe. I do this work with numerous collaborators, including members of the ISM*@ST Group
At STScI I am the Head of the Data Science Mission Office and I am the PI of the Mikulski Archive for Space Telescopes.