On the Interpretation of the l–v Features in the Milky Way Galaxy

Abstract

Abstract We modeled the gas dynamics of barred galaxies using a three-dimensional, high-resolution, $N$-body $+$ hydrodynamical simulation, and applied it to the Milky Way in an attempt to reproduce both the large-scale structure and the clumpy morphology observed in galactic HI and CO $l$–$v$ diagrams. Owing to including of the multi-phase interstellar medium, self-gravity, star-formation, and supernovae feedback, the clumpy morphology, as well as the large-scale features, in observed $l$–$v$ diagrams were naturally reproduced. We identified in our $l$–$v$ diagrams with a number of not only large-scale peculiar features, such as the `3-kpc arm', `135-km s$^{-1}$ arm', and `Connecting arm', but also clumpy features, such as `Bania clumps', and then linked these features in a face-on view of our model. We give suggestions on the real structure of the Milky Way and on the fate of gas clumps in the central region.