Research Interests


My primary research interest is the physical structure and evolution of the multi-phase interstellar medium (ISM) in galaxies. The structure and evolution of the multi-phase ISM in a galaxy is largely determined by its interaction with massive stars. The stellar winds and supernova explosions of massive stars carve a bubble of hot 106 K ionized gas into the ambient ISM, surrounded by a thin, dense shell. In general, massive stars will form discrete wind-blown bubbles and supernova remnants (SNRs) if they are isolated, superbubbles if there is a single burst of star formation, or supergiant shells if there are multiple bursts of star formation that have taken place over a period of time in a concentrated area. If the ambient interstellar density is low or highly clumped, the hot gas interior to these shells may breakout and vent the chemically-enriched hot gas into the lower density medium. The hot gas from isolated SNRs would largely be confined to the galactic disk. The hot gas from the interiors of superbubbles and supergiant shells may be vented into the halo of the galaxy because their dimensions are comparable to the scale height of gas in the disk. If the gravitational potential of the galaxy is large enough the hot gas in the halo will eventually cool and rain back down on the disk. Otherwise, the hot gas can escape the host galaxy and produce a galactic wind. Thus, the evolution of galaxies themselves is dependent upon the evolution and physical structure of ISM.


Past and Current Research


To better understand the physical structure of the multi-phase ISM and its interaction with massive stars, I have examined the nature and origin of the large-scale diffuse X-ray emission from the Large Magellanic Cloud (LMC) for my Ph.D. thesis project. This research consists of: (1) determining the spatial distribution and physical properties of the 106 K gas; (2) examining the relationship between the 106 K gas and the ionized 104 K gas; and (3) performing a detailed study of the multi-phase ISM of the supergiant shell LMC 2 and its underlying stellar population.