Topology of HI Gas Distribution in the Large Magellanic Cloud

We have analyzed the H I aperture synthesis image of the Large Magellanic Cloud (LMC), using an objective and quantitative measure of topology to understand the H I distribution hosting a number of holes and clumps of various sizes in the medium. The H I distribution shows different topology at four different chosen scales. At the smallest scales explored (19 ∼ 29 pc), the H I mass is distributed in such a way that numerous clumps are embedded on top of a low density background. At the larger scales from 73 to 194 pc, it shows a generic hole topology. These holes might have been formed mainly by stellar winds from hot stars. At the scales from 240 to 340 pc, slightly above the disk scale-height of the gaseous disk, major clumps in the H I map change the distribution to have a slight clump topology. These clumps include the giant cloud associations in the spiral arms and the thick filaments surrounding superholes. At the largest scales studied (390 ∼ 485 pc), the hole topology is present again. Responsible to the hole topology at this scale are a few superholes which seem mainly associated with supernova explosions in the outer disk. The gaps between the bar and spiral arms have a minor effect on the topology at this scale. Subject headings: galaxies: individual (Large Magellanic Cloud) — galaxies: ISM — ISM: neutral hydrogen — Magellanic Clouds — radio lines: HI