A cluster in the making: ALMA reveals the initial conditions for high-mass cluster formation
Author
dc.contributor.author
Rathborne, Jill
Author
dc.contributor.author
Longmore, S. N.
Author
dc.contributor.author
Jackson, J. M.
Author
dc.contributor.author
Alves, J. F.
Author
dc.contributor.author
Bally, J.
Author
dc.contributor.author
Bastian, N.
Author
dc.contributor.author
Contreras, Y.
Author
dc.contributor.author
Foster, J. B.
Author
dc.contributor.author
Garay Brignardello, Guido
Author
dc.contributor.author
Kruijssen, J. M.
Author
dc.contributor.author
Testi, L.
Author
dc.contributor.author
Walsh, A. J.
Admission date
dc.date.accessioned
2015-08-05T14:17:50Z
Available date
dc.date.available
2015-08-05T14:17:50Z
Publication date
dc.date.issued
2015
Cita de ítem
dc.identifier.citation
The Astrophysical Journal, 802:125 (20pp), 2015 April 1
en_US
Identifier
dc.identifier.other
DOI: 10.1088/0004-637X/802/2/125
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/132398
General note
dc.description
Artículo de publicación ISI
en_US
Abstract
dc.description.abstract
G0.253+0.016 is a molecular clump that appears to be on the verge of forming a high-mass cluster: its extremely low dust temperature, high mass, and high density, combined with its lack of prevalent star formation, make it an excellent candidate for an Arches-like cluster in a very early stage of formation. Here we present new Atacama Large Millimeter/Sub-millimeter Array observations of its small-scale (similar to 0.07 pc) 3 mm dust continuum and molecular line emission from 17 different species that probe a range of distinct physical and chemical conditions. The data reveal a complex network of emission features with a complicated velocity structure: there is emission on all spatial scales, the morphology of which ranges from small, compact regions to extended, filamentary structures that are seen in both emission and absorption. The dust column density is well traced by molecules with higher excitation energies and critical densities, consistent with a clump that has a denser interior. A statistical analysis supports the idea that turbulence shapes the observed gas structure within G0.253+0.016. We find a clear break in the turbulent power spectrum derived from the optically thin dust continuum emission at a spatial scale of similar to 0.1 pc, which may correspond to the spatial scale at which gravity has overcome the thermal pressure. We suggest that G0.253+0.016 is on the verge of forming a cluster from hierarchical, filamentary structures that arise from a highly turbulent medium. Although the stellar distribution within high-mass Arches-like clusters is compact, centrally condensed, and smooth, the observed gas distribution within G0.253+0.016 is extended, with no high-mass central concentration, and has a complex, hierarchical structure. If this clump gives rise to a high-mass cluster and its stars are formed from this initially hierarchical gas structure, then the resulting cluster must evolve into a centrally condensed structure via a dynamical process.