The VMC Survey XXVII. Young Stellar Structures in the LMC${}^{\prime }$s Bar Star-Forming Complex

Abstract

Star formation is a hierarchical process, forming young stellar structures of star clusters, associations, and complexes over a wide scale range. 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 non-uniform 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($\tau$/yr)~=~7.2, contains most substructure, progressively older ones are less and less substructured. The oldest subsample, with a median age of log($\tau$/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 $\sim$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.

arXiv comment17 pages, 15 figures. Accepted for publication in ApJ

References in corpus (65)

• PARSEC: stellar tracks and isochrones with the PAdova and TRieste Stellar Evolution Code
• Control of star formation by supersonic turbulence
• Interstellar Turbulence I: Observations and Processes
• Comparing the statistics of interstellar turbulence in simulations and observations: Solenoidal versus compressive turbulence forcing
• Spitzer Survey of the Large Magellanic Cloud, Surveying the Agents of a Galaxy's Evolution (SAGE) I: Overview and Initial Results
• An eclipsing binary distance to the Large Magellanic Cloud accurate to 2 per cent
• Structural Analysis of Molecular Clouds: Dendrograms
• The Star Formation History of the Large Magellanic Cloud
• The Magellanic Clouds Photometric Survey: The Large Magellanic Cloud Stellar Catalog and Extinction Map
• The Star Formation History of the Small Magellanic Cloud
• The Galactic disk mass-budget : I. stellar mass-function and density
• Physical Properties and Galactic Distribution of Molecular Clouds identified in the Galactic Ring Survey
• Cluster-formation in the Rosette molecular cloud at the junctions of filaments
• The Spatial Distribution of Star Formation in the Solar Neighbourhood: Do all stars form in clusters?
• The VMC Survey - I. Strategy and First Data
• One-Point Probability Distribution Functions of Supersonic Turbulent Flows in Self-Gravitating Media
• The Second Survey of the Molecular Clouds in the Large Magellanic Cloud by NANTEN I: Catalog of Molecular Clouds
• Cluster Mass Functions in the Large and Small Magellanic Clouds: Fading and Size of Sample Effects
• Hierarchical Star Formation from the Time-Space Distribution of Star Clusters in the Large Magellanic Cloud
• A Correlation Between Surface Densities of Young Stellar Objects and Gas in Eight Nearby Molecular Clouds
• The Visible and Infrared Survey Telescope for Astronomy (VISTA): Design, Technical Overview and Performance
• The Fractal Density Structure in Supersonic Isothermal Turbulence: Solenoidal versus Compressive Energy Injection
• The VISTA Science Archive
• Clustering of Local Group distances: publication bias or correlated measurements? I. The Large Magellanic Cloud
• The Initial Configuration of Young Stellar Clusters: A K-band Number Counts Analysis of the Surface Density of Stars
• A Method for Determining the Star Formation History of a Mixed Stellar Population
• Clusters in the inner spiral arms of M51: the cluster IMF and the formation history
• New Optical Reddening Maps of the Large and Small Magellanic Clouds
• Star Cluster Formation and Evolution in Nearby Starburst Galaxies: II. Initial Conditions
• The Magellanic Stream: Circumnavigating the Galaxy
• On the evolution of the density pdf in strongly self-gravitating systems
• Clustering of Local Group distances: publication bias or correlated measurements? III. The Small Magellanic Cloud
• The VMC Survey - XIV. First results on the look-back time star-formation rate tomography of the Small Magellanic Cloud
• Revised bolometric corrections and interstellar extinction coefficients for the ACS and WFPC2 photometric systems
• Fractal Structure in Galactic Star Fields
• Hierarchical Star Formation in the Spiral Galaxy NGC 628
• Young Stellar Groups and Their Most Massive Stars
• The Spatial Evolution of Stellar Structures in the LMC
• Clouds, Streams and Bridges. Redrawing the blueprint of the Magellanic System with Gaia DR1
• How well do we know the age and mass distributions of the star cluster system in the Large Magellanic Cloud?
• A new density variance - Mach number relation for subsonic and supersonic, isothermal turbulence
• The VMC Survey IV. The LMC star formation history and disk geometry from four VMC tiles
• The spatial distribution of stars in open clusters
• The Fractal Dimension of Projected Clouds
• The structures of embedded clusters in the Perseus, Serpens and Ophiuchus molecular clouds
• Spatial Distributions of Young Stars
• Hierarchical Star-Formation in M33: Fundamental properties of the star-forming regions
• Self-gravity as an explanation of the fractal structure of the interstellar medium
• Massive Field Stars and the Stellar Clustering Law
• The Complex Distribution of Recently Formed Stars. Bimodal Stellar Clustering in the Star-Forming Region NGC 346
• The binary fractions in the massive young Large Magellanic Cloud star clusters NGC 1805 and NGC 1818
• Star cluster "infant mortality" in the Small Magellanic Cloud (Redivivus)
• Hierarchical Star Formation in Nearby LEGUS Galaxies
• Dynamical Influences of the Last Magellanic Interaction On the Magellanic Clouds
• Evolution of stellar structure in the Small Magellanic Cloud
• Stellar Clusters in NGC 1313: Evidence for Infant Mortality
• The VMC Survey - XXIV. Signatures of tidally stripped stellar populations from the inner Small Magellanic Cloud
• Hierarchical star formation across the grand design spiral NGC1566
• Hierarchical Stellar Structures in the Local Group Dwarf Galaxy NGC 6822
• On the Recovery of the Star Formation History of the LMC from the VISTA Survey of the Magellanic System
• Hierarchical structures in the Large and Small Magellanic Clouds
• The VMC Survey XXII. Hierarchical Star Formation in the 30 Doradus-N158-N159-N160 Star-Forming Complex
• Hierarchy and size distribution function of star formation regions in the spiral galaxy NGC 628
• The VMC survey - XVI. Spatial variation of the cluster-formation activity in the innermost regions of the Large Magellanic Cloud
• Hierarchy of Interstellar and Stellar Structures and the Case of the Orion Star-Forming Region

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