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 theHi distribution, which hosts a number of holes and clumps of various sizes, in the interstellar medium. The H I distribution shows different topologies 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 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 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 for the hole topology at this scale are a few superholes that seem to be mainly associated with supernova explosions in the outer disk. The gaps between the bar and the spiral arms have a minor effect on the topology at this scale.