Rhea-RT: Dynamical impact of Central Molecular Zone conditions on the properties of the interstellar medium and stellar feedback coupling
Journal article, 2026
The Central Molecular Zone (CMZ) is an extreme star formation environment, characterized by higher density, higher turbulence, stronger orbital shear, and stronger magnetic field strength than the solar neighborhood. It is still debated whether classical theories of star formation hold within this extreme environment. In order to assess the impact of these different conditions on the interstellar medium (ISM) and on star formation, we present radiation magnetohydrodynamic AREPO simulations of a Milky Way-type galaxy. We set up a high-resolution (M cell = 20 M⊙) region in a ring around the solar radius and in the barred region of the Galaxy to have a coherent comparison between the CMZ and the solar neighborhood. Although the high densities and strong levels of turbulence affect star formation and feedback, a key difference in the regulation of star formation between the two environments comes from the short orbital times and the strong shear in the CMZ. In particular, we highlight the role of the quick dynamical decoupling of stars and gas, which leads to periodic re-embedding events in the early lifetimes of radiating O stars. Young stellar associations are efficiently sheared apart, such that the ISM is deprived of the compounding effect of radiation and supernovae in disrupting molecular clouds. This dramatically changes the evolution of giant molecular clouds and how feedback can regulate star formation in the CMZ. Stellar feedback is no longer directly coupled to the molecular cloud from which they formed, and no strong and disruptive superbubbles can develop. The feedback instead rather acts as a background source of turbulence.
ISM: kinematics and dynamics
stars: formation
galaxy: center
galaxies: ISM
Author
Robin G. Tress
Swiss Federal Institute of Technology in Lausanne (EPFL)
N. Brucy
Heidelberg University
École Normale Supérieure de Lyon
P. Girichidis
Heidelberg University
S. C.O. Glover
Heidelberg University
J. Göller
Heidelberg University
Michaela Hirschmann
Swiss Federal Institute of Technology in Lausanne (EPFL)
R. S. Klessen
Heidelberg University
T. Peter
Heidelberg University
J. Petersson
Swiss Federal Institute of Technology in Lausanne (EPFL)
Mattia C. Sormani
University of Insubria
Lucia Armillotta
University of Florence
C. Battersby
University of Connecticut
M. Donati
University of Insubria
Z. X. Feng
University of Insubria
Jonathan D. Henshaw
Max Planck Society
D. Lipman
University of Connecticut
S. Longmore
Liverpool John Moores University
Francisco Nogueras-Lara
Spanish National Research Council (CSIC)
V. M. Pelkonen
Istituto nazionale di astrofisica (INAF)
N. Peschken
University of Florence
Maya Petkova
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Adèle Plat
Swiss Federal Institute of Technology in Lausanne (EPFL)
S. Reissl
Heidelberg University
R. Smith
University of St Andrews
J. D. Soler
University of Vienna
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 711 A103Subject Categories (SSIF 2025)
Astronomy, Astrophysics, and Cosmology
DOI
10.1051/0004-6361/202558503
Related datasets
Movies of the simulation [dataset]
DOI: 10.7910/DVN/ULCTSZ