CHRISTOPHER W CHURCHILL
PROFESSOR
DEPARTMENT OF ASTRONOMY
NEW MEXICO STATE UNIVERSITY


Welcome! I study the evolution of galaxies by examining their circumgalactic medium (CGM), a gaseous reservoir of dynamically complex, multi-phase, metal enriched gas that surrounds galaxies. The gas is observed in absorption using the technique of quasar absorption lines. When a quasar resides behind a galaxy, the GCM gas imprints absorption patterns in the spectrum of the quasar. From these we measure the gas temperature, metallicity, kinematics, etc. We aim to learn about the role of the cycle of gas (called the baryon cycle) in governing the formation and evolution of galaxies.


(left) A QSO quasar spectrum with emission lines annotated and (across the top) with spectral regions annotated for the various ions that can be observed in absorption. (right) A combined optical and radio image of the galaxy M81. The radio emission (orange) shows how the gas is dstributed around the stars (white).