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

Autor(en)

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

Abstrakt

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(en)

Institut für Astrophysik

Externe Organisation(en)

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

Band

436

Seiten

1836-1851

Anzahl der Seiten

16

ISSN

0035-8711

DOI

https://doi.org/10.1093/mnras/stt1698

Publikationsdatum

12-2013

Peer-reviewed

Ja

ÖFOS 2012

103004 Astrophysik, 103003 Astronomie

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/4ddcc078-24a6-4d56-87f6-101d1b46833c