Kinematics of Galactic Centre clouds shaped by shear-seeded solenoidal turbulence
Artikel i vetenskaplig tidskrift, 2023
The Central Molecular Zone (CMZ; the central ∼500 pc of the Galaxy) is a kinematically unusual environment relative to the Galactic disc, with high-velocity dispersions and a steep size-linewidth relation of the molecular clouds. In addition, the CMZ region has a significantly lower star formation rate (SFR) than expected by its large amount of dense gas. An important factor in explaining the low SFR is the turbulent state of the star-forming gas, which seems to be dominated by rotational modes. However, the turbulence driving mechanism remains unclear. In this work, we investigate how the Galactic gravitational potential affects the turbulence in CMZ clouds. We focus on the CMZ cloud G0.253+0.016 ('the Brick'), which is very quiescent and unlikely to be kinematically dominated by stellar feedback. We demonstrate that several kinematic properties of the Brick arise naturally in a cloud-scale hydrodynamics simulation, that takes into account the Galactic gravitational potential. These properties include the line-of-sight velocity distribution, the steepened size-linewidth relation, and the predominantly solenoidal nature of the turbulence. Within the simulation, these properties result from the Galactic shear in combination with the cloud's gravitational collapse. This is a strong indication that the Galactic gravitational potential plays a crucial role in shaping the CMZ gas kinematics, and is a major contributor to suppressing the SFR, by inducing predominantly solenoidal turbulent modes.
ISM: evolution
ISM: kinematics and dynamics
stars: formation
ISM: clouds
Galaxy: centre
galaxies: ISM
Författare
Maya Petkova
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Astronomisches Rechen-Institut Heidelberg
J. M. D. Kruijssen
Technische Universität München
COOL Research DAO
Jonathan D. Henshaw
Max-Planck-Gesellschaft
Liverpool John Moores University
S. Longmore
Liverpool John Moores University
COOL Research DAO
S. C.O. Glover
Universität Heidelberg
Mattia C. Sormani
Universität Heidelberg
Lucia Armillotta
Princeton University
Ashley T. Barnes
Universität Bonn
R. S. Klessen
Universität Heidelberg
Francisco Nogueras-Lara
European Southern Observatory (ESO)
Robin G. Tress
Observatoire de Sauverny
Jairo Armijos-Abendaño
Escuela Politécnica Nacional
Cardiff University
L. Colzi
Centro de Astrobiologia (CAB)
C. Federrath
Australian National University
Australian Research Council (ARC)
P. J.V. Garcia
Universidad Catolica del Norte
Chinese Academy of Sciences
A. Ginsburg
University of Florida
C. Henkel
King Abdulaziz University
Max-Planck-Gesellschaft
S. Martin
European Southern Observatory Santiago
Atacama Large Millimeter-submillimeter Array (ALMA)
D. Riquelme
Universidad de La Serena
Max-Planck-Gesellschaft
Víctor M. Rivilla
Centro de Astrobiologia (CAB)
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 525 1 962-968Ämneskategorier (SSIF 2011)
Astronomi, astrofysik och kosmologi
Annan fysik
DOI
10.1093/mnras/stad2344