SEDIGISM-ATLASGAL: Dense gas fraction and star formation efficiency across the Galactic disc
Journal article, 2021
By combining two surveys covering a large fraction of the molecular material in the Galactic disc, we investigate the role spiral arms play in the star formation process. We have matched clumps identified by APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) with their parental giant molecular clouds (GMCs) as identified by SEDIGISM, and use these GMC masses, the bolometric luminosities, and integrated clump masses obtained in a concurrent paper to estimate the dense gas fractions (DGFgmc = ΣMclump/Mgmc) and the instantaneous star formation efficiencies (i.e. SFEgmc = ΣLclump/Mgmc). We find that the molecular material associated with ATLASGAL clumps is concentrated in the spiral arms (∼60 per cent found within ±10 km s-1 of an arm).We have searched for variations in the values of these physical parameters with respect to their proximity to the spiral arms, but find no evidence for any enhancement that might be attributable to the spiral arms. The combined results from a number of similar studies based on different surveys indicate that, while spiral-arm location plays a role in cloud formation and HI to H2 conversion, the subsequent star formation processes appear to depend more on local environment effects. This leads us to conclude that the enhanced star formation activity seen towards the spiral arms is the result of source crowding rather than the consequence of any physical process.
Stars: Formation
Surveys
Galaxy: Kinematics and dynamics
ISM: Clouds
Submillimetre: ISM
Galaxy: Structure
Author
J. S. Urquhart
University Of Kent
C. Figura
Wartburg College
J. R. Cross
University Of Kent
M. Wells
University Of Kent
T. J.T. Moore
Liverpool John Moores University
D. J. Eden
Liverpool John Moores University
S. E. Ragan
Cardiff University
A. R. Pettitt
Hokkaido University
A. Duarte-Cabral
Cardiff University
D. Colombo
Max Planck Society
F. Schuller
Max Planck Society
Leibniz Institute for Astrophysics Potsdam
T. Csengeri
University of Bordeaux
M. Mattern
Max Planck Society
University Paris-Saclay
H. Beuther
Max Planck Society
K. M. Menten
Max Planck Society
F. Wyrowski
Max Planck Society
L. D. Anderson
West Virginia University
P. J. Barnes
Space Science Institute
M. Beltrán
Arcetri Astrophysical Observatory
S. J. Billington
University Of Kent
Leonardo Bronfman
University of Chile (UCH)
A. Giannetti
Istituto di Radioastronomia
Jouni Kainulainen
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
J. Kauffmann
Massachusetts Institute of Technology (MIT)
M. Y. Lee
Korea Astronomy and Space Science Institute
S. Leurini
Istituto nazionale di astrofisica (INAF)
S. N.X. Medina
Max Planck Society
F.M. Montenegro-Montes
European Southern Observatory Santiago
Manuel Riener
Max Planck Society
Andrew Rigby
Cardiff University
A. Sanchez-Monge
University of Cologne
P. Schilke
University of Cologne
E. Schisano
Istituto nazionale di astrofisica (INAF)
A. Traficante
Istituto nazionale di astrofisica (INAF)
M. Wienen
University of Exeter
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 500 3 3050-3063Subject Categories
Astronomy, Astrophysics and Cosmology
Chemical Process Engineering
Other Chemistry Topics
DOI
10.1093/mnras/staa2512