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.

Galaxy: centre

stars: formation

ISM: kinematics and dynamics

galaxies: ISM

ISM: evolution

ISM: clouds

Författare

Maya Petkova

Astronomisches Rechen-Institut Heidelberg

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik

J. M. D. Kruijssen

Technische Universität München

Coolresearch.io

Jonathan D. Henshaw

Liverpool John Moores University

Max-Planck-Gesellschaft

S. Longmore

Coolresearch.io

Liverpool John Moores University

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

Max-Planck-Gesellschaft

Universidad de La Serena

Víctor M. Rivilla

Centro de Astrobiologia (CAB)

Monthly Notices of the Royal Astronomical Society

0035-8711 (ISSN) 1365-2966 (eISSN)

Vol. 525 1 962-968

Ämneskategorier

Astronomi, astrofysik och kosmologi

Annan fysik

DOI

10.1093/mnras/stad2344

Mer information

Senast uppdaterat

2023-10-03