Sun, N-C, Grijs, RD, Subramanian, S, Bekki, K, Bell, CPM, Cioni, M-RL, Ivanov, VD, Marconi, M, Oliveira, JM, Piatti, AE, Ripepi, V, Rubele, S, Tatton, BL and Loon, JTV (2017) The VMC Survey. XXVII. Young Stellar Structures in the LMC’s Bar Star-forming Complex. Astrophysical Journal, 849 (2). 149 -149. ISSN 0004-637X

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Star formation is a hierarchical process, forming young stellar structures of star clusters, associations, and complexes over a wide range of scales. The star-forming complex in the bar region of the Large Magellanic Cloud is investigated with upper main-sequence stars observed by the VISTA Survey of the Magellanic Clouds. The upper main-sequence stars exhibit highly nonuniform distributions. Young stellar structures inside the complex are identified from the stellar density map as density enhancements of different significance levels. We find that these structures are hierarchically organized such that larger, lower-density structures contain one or several smaller, higher-density ones. They follow power-law size and mass distributions, as well as a lognormal surface density distribution. All these results support a scenario of hierarchical star formation regulated by turbulence. The temporal evolution of young stellar structures is explored by using subsamples of upper main-sequence stars with different magnitude and age ranges. While the youngest subsample, with a median age of log( τ /yr) = 7.2, contains the most substructure, progressively older ones are less and less substructured. The oldest subsample, with a median age of log( τ /yr) = 8.0, is almost indistinguishable from a uniform distribution on spatial scales of 30–300 pc, suggesting that the young stellar structures are completely dispersed on a timescale of ∼100 Myr. These results are consistent with the characteristics of the 30 Doradus complex and the entire Large Magellanic Cloud, suggesting no significant environmental effects. We further point out that the fractal dimension may be method dependent for stellar samples with significant age spreads.

Item Type: Article
Additional Information: This is the final published version of the article (version of record). It first appeared online via IOP Science at - please refer to any applicable terms of use of the publisher.
Uncontrolled Keywords: infrared, stars, Magellanic Clouds, formation, space and planetary science
Subjects: Q Science > QB Astronomy > QB460 Astrophysics
Divisions: Faculty of Natural Sciences > School of Chemical and Physical Sciences
Depositing User: Symplectic
Date Deposited: 21 Nov 2017 12:17
Last Modified: 19 Mar 2018 14:34

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