A sub-parsec resolution simulation of the Milky Way: global structure of the interstellar medium and properties of molecular clouds

Author(s)
F. Renaud, F. Bournaud, E. Emsellem, B. Elmegreen, R. Teyssier, J. Alves, D. Chapon, F. Combes, A. Dekel, J. Gabor, P. Hennebelle, K. Kraljic
Abstract

We present a self-consistent hydrodynamical simulation of a Milky

Way-like galaxy at a resolution of 0.05 pc. The model includes star

formation and a new implementation of stellar feedback through

photoionization, radiative pressure and supernovae. The simulation

resolves the structure of the interstellar medium at sub-parsec

resolution for a few cloud lifetimes and at 0.05 pc for about a

cloud-crossing time. The turbulence cascade and gravitation from kpc

scales are de facto included in smaller structures like molecular

clouds. We show that the formation of a bar influences the dynamics of

the central ˜100 pc by creating resonances. At larger radii, the

spiral arms host the formation of regularly spaced clouds: beads on a

string and spurs. These instabilities pump turbulent energy into the

gas, generally in the supersonic regime. Because of asymmetric drift,

the supernovae explode outside their gaseous nursery, which diminishes

the effect of feedback on the structure of clouds. The evolution of

clouds is thus mostly due to fragmentation and gas consumption,

regulated mainly by supersonic turbulence. The transition from

turbulence-supported to self-gravitating gas is detected in the gas

density probability distribution function at ˜2000

cm-3. The power-spectrum density suggests that gravitation

governs the hierarchical organization of structures from the galactic

scale down to a few pc.

Organisation(s)
Department of Astrophysics
External organisation(s)
European Southern Observatory (Germany), Université Paris VII - Paris-Diderot, Université Claude-Bernard-Lyon-I, IBM T. J. Watson Research Center, Universität Zürich (UZH), Université de recherche Paris Sciences et Lettres, Hebrew University Jerusalem
Journal
Monthly Notices of the Royal Astronomical Society
Volume
436
Pages
1836-1851
No. of pages
16
ISSN
0035-8711
DOI
https://doi.org/10.1093/mnras/stt1698
Publication date
12-2013
Peer reviewed
Yes
Austrian Fields of Science 2012
103004 Astrophysics, 103003 Astronomy
Keywords
Portal url
https://ucrisportal.univie.ac.at/en/publications/4ddcc078-24a6-4d56-87f6-101d1b46833c