PECULIAR GAS-DYNAMICS IN THE STARBURST GALAXY NGC-253

Here we present our first results of a study of the neutral hydrogen g as (HI) in the southern spiral galaxy NGC 253 with the Australia Teles cope Compact Array. The relative proximity of NGC 253 makes it a very suitable object for detailed studies of large-scale, as well as nuclea r, gas dynamics. Several peculiar features have been found. The HI dis tribution is asymmetric in the outer regions, probably as a result of the strong warping of the spiral arms. A bar associated with the disc, clearly visible in the optical and near-infrared, also reveals its si gnature in the neutral hydrogen gas. HI absorption measurements reveal unusual motions of the gas in the nuclear region which seem to indica te a fast-rotating ring of cold gas as well as outflow of gas. Similar features have been found in other starburst galaxies, such as M 82, N GC 1808 and NGC 4945, and are interpreted in terms of bar-induced gas dynamics and star formation.