ALMA Central Molecular Zone Exploration Survey (ACES) - VI. ALMA large program reveals a highly filamentary Central Molecular Zone
Journal article, 2026
The Central Molecular Zone (CMZ) of the Milky Way is the way station that primarily controls how much gas flows from the disc of the Galaxy towards the central nucleus. While this region is well documented to have extreme gas properties that clearly distinguish it from the rest of the Galaxy, the properties of the bulk molecular gas at high angular resolution are relatively unexplored. Band 3 data from the ALMA (Atacama Large Millimeter/Submillimeter Array) large program ACES (ALMA CMZ Exploration Survey) reveal the highly filamentary nature of CMZ molecular gas at high resolution (3 arcsec or similar to 0.1 pc) across the entire CMZ. Visual inspection of these data suggests that there are at least two general classes of elongated structures, which we identify as: (i) large-scale (less than or similar to 10 pc) filamentary structures (LFs) and (ii) a ubiquitous population of small-scale (similar to 1 pc) filamentary structures (SFs), both with widths (FWHM) of about 0.1 pc. We present detailed morphological and kinematic properties towards three structures in each category, as well as their association with magnetic fields and the correlation of HNCO 4(0,4)-3(0,3) with other molecularspecies. Ourinvestigation revealsthat these structures are largely coherent in position-position-velocity space. The alignment with the magnetic field structure is mixed, with some parallel,some perpendicular, and some intermediate alignments. We find that LFslikely trace pieces of contiguous CMZ orbital structures and are a manifestation of global CMZ dynamics. The second class, SFs, are pervasive and may be the result of complicated turbulence and shearing dynamics in the CMZ gas flows, as seen in numerical simulations.
ISM: molecules
submillimetre: ISM
ISM: general
Galaxy: centre
stars: formation
Author
Cara Battersby
University of Connecticut
Miriam G. Santa-Maria
Spanish National Research Council (CSIC)
University of Florida
Dani Lipman
University of Connecticut
Dylan M. Pare
Villanova University
Rachel R. Lee
University of Connecticut
Pablo Garcia
Universidad Catolica del Norte
Chinese Academy of Sciences
Izaskun Jimenez-Serra
Spanish National Research Council (CSIC)
Xing Pan
Nanjing University
Harvard-Smithsonian Center for Astrophysics
Daniel L. Walker
University of Manchester
Jack Sullivan
University of Connecticut
Danya Alboslani
University of Connecticut
H. Perry Hatchfield
California Institute of Technology (Caltech)
University of Connecticut
Yue Hu
Princeton University
Alex Lazarian
University of Wisconsin Madison
Jennifer Wallace
University of Connecticut
Qizhou Zhang
Harvard-Smithsonian Center for Astrophysics
Xing Lu
Chinese Academy of Sciences
Elisabeth A. C. Mills
University of Kansas
Adam Ginsburg
California Institute of Technology (Caltech)
Ashley T. Barnes
European Southern Observatory (ESO)
Pei-Ying Hsieh
National Astronomical Observatory of Japan
Jonathan D. Henshaw
Max Planck Society
Liverpool John Moores University
Steven N. Longmore
COOL Research DAO
Liverpool John Moores University
John Bally
University of Colorado
Laura Colzi
Spanish National Research Council (CSIC)
Paul T. P. Ho
East Asian Observatory
Academia Sinica
Maya Petkova
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Mattia C. Sormani
University of Surrey
University of Insubria
N. Bijas
University of Manchester
Alyssa Bulatek
University of Florida
Natalie O. Butterfield
National Radio Astronomy Observatory
Christoph Federrath
Australian National University
Simon C. O. Glover
Heidelberg University
Mark D. Gorski
Northwestern University
Savannah R. Gramze
University of Florida
Christian Henkel
Max Planck Society
Janik Karoly
University College London (UCL)
Ralf S. Klessen
Heidelberg University
Harvard University
Harvard-Smithsonian Center for Astrophysics
Sergio Martin
Atacama Large Millimeter-submillimeter Array (ALMA)
European Southern Observatory Santiago
Francisco Nogueras-Lara
Spanish National Research Council (CSIC)
European Southern Observatory (ESO)
Jaime E. Pineda
Max Planck Society
Denise Riquelme-Vasquez
University of La Serena
Victor M. Rivilla
Spanish National Research Council (CSIC)
Alvaro Sanchez-Monge
Inst Estudis Espacials Catalunya IEEC
Spanish National Research Council (CSIC)
Anika Schmiedeke
Green Bank Observatory
Yoshiaki Sofue
University of Tokyo
Volker Tolls
Harvard-Smithsonian Center for Astrophysics
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 550 3 stag1119Subject Categories (SSIF 2025)
Atom and Molecular Physics and Optics
Astronomy, Astrophysics, and Cosmology
DOI
10.1093/mnras/stag1119