Discovery of Large-Scale Gravitational Infall in a Massive Protostellar Cluster

Abstract

We report Mopra (ATNF), Anglo-Australian Telescope, and Atacama Submillimeter Telescope Experiment observations of a molecular clump in Carina, BYF73 = G286.21+0.17, which give evidence of large-scale gravitational infall in the dense gas. From the millimetre and far-infrared data, the clump has mass ~ 2 x 10^4 Msun, luminosity ~ 2-3 x 10^4 Lsun, and diameter ~ 0.9 pc. From radiative transfer modelling, we derive a mass infall rate ~ 3.4 x 10^-2 Msun yr-1. If confirmed, this rate for gravitational infall in a molecular core or clump may be the highest yet seen. The near-infrared K-band imaging shows an adjacent compact HII region and IR cluster surrounded by a shell-like photodissociation region showing H2 emission. At the molecular infall peak, the K imaging also reveals a deeply embedded group of stars with associated H2 emission. The combination of these features is very unusual and we suggest they indicate the ongoing formation of a massive star cluster. We discuss the implications of these data for competing theories of massive star formation.

v1: 23 pages single-column, 6 figures (some multipart) at end v2: 14 pages 2-column, 6 figures interspersed v3: edited to referee's comments with new sections and new figures; accepted to MNRAS, 20 pages 2-column, 8 figures (some multipart) interspersed

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Cited by in corpus (25)

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• SEDIGISM: Structure, excitation, and dynamics of the inner Galactic interstellar medium
• The Galactic Census of High- and Medium-mass Protostars. I. Catalogues and First Results from Mopra HCO+ Maps
• The Core Mass Function in the Massive Protocluster G286.21+0.17 revealed by ALMA
• The Carina Nebula and Gum 31 molecular complex: I. Molecular gas distribution, column densities and dust temperatures
• The Galactic Census of High- and Medium-mass Protostars. II. Luminosities and Evolutionary States of a Complete Sample of Dense Gas Clumps
• Discovering young stars in the Gum 31 region with infrared observations
• Millimetre-Wave and Near-Infrared Signposts of Massive Molecular Clump Evolution and Star Cluster Formation
• G30.79~FIR~10: A gravitationally bound infalling high-Mass star forming clump
• The Galactic Census of High- and Medium-mass Protostars. III ${}^{12}$CO Maps and Physical Properties of Dense Clump Envelopes and their Embedding GMCs
• Evidence of Core Growth in the Dragon Infrared Dark Cloud: A Path for Massive Star Formation
• Searching for Inflow Towards Massive Starless Clump Candidates Identified in the Bolocam Galactic Plane Survey
• ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions -- VI. On the formation of the "L" type filament in G286.21+0.17
• Discovery of Infalling Motion with Rotation of the Cluster-Forming Clump S235AB and Its Implication to the Clump Structures
• On the Diagnostic Power of FIR/Sub-mm SED Fitting in Massive Galactic Molecular Clumps
• The stellar content of the infalling molecular clump G286.21+0.17
• Molecular Clouds: Internal Properties, Turbulence, Star Formation and Feedback
• Gas Kinematics of the Massive Protocluster G286.21+0.17 Revealed by ALMA
• The Radio-FIR correlation in the Milky Way
• SOFIA and ALMA Investigate Magnetic Fields and Gas Structures in Massive Star Formation: The Case of the Masquerading Monster in BYF 73
• Studying Infall in Infrared Dark Clouds with Multiple HCO+ Transitions
• Gemini, SOFIA, and ATCA Reveal Very Young, Massive Protostars in the Collapsing Molecular Cloud BYF 73
• Stellar Variability in a Forming Massive Star Cluster
• The Disk Population in a Distant Massive Protocluster
• Massive star formation in the Carina nebula complex and Gum 31 -- II. a cloud-cloud collision in Gum 31