The Spatial Evolution of Young Massive Clusters I. A New Tool to Quantitatively Trace Stellar Clustering

Abstract

Aims. To present the new novel statistical clustering tool 'INDICATE' which assesses and quantifies the degree of spatial clustering of each object in a dataset, discuss its applications as a tracer of morphological stellar features in star forming regions, and to look for these features in the Carina Nebula (NGC 3372). Results. We successfully recover known stellar structure of the Carina Nebula, including the 5 young star clusters in this region. Four sub-clusters contain no, or very few, stars with a degree of association above random which suggests they may be fluctuations in the field rather than real clusters. In addition we find: (1) Stars in the NW and SE regions have significantly different clustering tendencies, which is reflective of differences in the apparent star formation activity in these regions. Further study is required to ascertain the physical origin of the difference; (2) The different clustering properties between these two regions are even more pronounced for OB stars; (3) There are no signatures of classical mass segregation present in the SE region - massive stars here are not spatially concentrated together above random; (4) Stellar concentrations are more frequent around massive stars than typical for the general population, particularly in the Tr14 cluster; (5) There is a relation between the concentration of OB stars and the concentration of (lower mass) stars around OB stars in the centrally concentrated Tr14 and Tr15, but no such relation exists in Tr16. We conclude this is due to the highly sub-structured nature of Tr16. Conclusions. INDICATE is a powerful new tool employing a novel approach to quantify the clustering tendencies of individual objects in a dataset within a user-defined parameter space. As such it can be used in a wide array of data analysis applications.

arXiv commentAccepted for publication in A&A; 15 pages, 10 figures, 3 appendices

References in corpus (20)

• Toward Understanding Massive Star Formation
• Global survey of star clusters in the Milky Way II. The catalogue of basic parameters
• The statistical Analysis of Star Clusters
• The Origin of Massive O-type Field Stars. Part II: Field O stars as runaways
• Using the minimum spanning tree to trace mass segregation
• The Formation and Early Evolution of Low-mass Stars and Brown Dwarfs
• Mass segregation and fractal substructure in young massive clusters: (I) the McLuster code and method calibration
• Dynamical evolution of star forming regions
• The Spatial Structure of Young Stellar Clusters. I. Subclusters
• Constraints on Massive Star Formation: Cygnus OB2 was always an Association
• The structures of embedded clusters in the Perseus, Serpens and Ophiuchus molecular clouds
• New infrared star clusters and candidates in the Galaxy detected with 2MASS
• Deep wide-field near-infrared survey of the Carina Nebula
• Dynamics versus structure: breaking the density degeneracy in star formation
• Comparisons between different techniques for measuring mass segregation
• A Chandra ACIS Study of the Young Star Cluster Trumpler 15 in Carina and Correlation with Near-infrared Sources
• The Chandra Carina Complex Project View of Trumpler 16
• Herschel far-infrared observations of the Carina Nebula complex II: The embedded young stellar and protostellar population
• A deep wide-field sub-mm survey of the Carina Nebula complex
• Clustering Properties of Stars in Simulations of Wind-Driven Star Formation

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• Dynamical evolution of fractal structures in star-forming regions
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• External photoevaporation of protoplanetary discs: does location matter?
• A tale of two clusters: dynamical history determines disc survival in Tr14 and Tr16 in the Carina Nebula
• The Spatial Evolution of Young Massive Clusters II. Looking for Imprints of Star Formation in NGC 2264 with Gaia DR2
• Constraints on star formation in NGC2264
• The Duration of Star Formation in Galactic Giant Molecular Clouds. I. The Great Nebula in Carina
• Star cluster formation and feedback in different environments of a Milky Way-like galaxy
• S2D2: Small-scale Significant substructure DBSCAN Detection I. NESTs detection in 2D star-forming regions
• Investigating the structure of star-forming regions using INDICATE
• On the origin of planetary-mass objects in NGC1333
• The evolution of phase space densities in star-forming regions
• Short-lived radioisotope enrichment in star-forming regions from stellar winds and supernovae
• The evolution of protoplanetary disc radii and disc masses in star-forming regions
• The velocity structure of Cygnus OB2
• Observational Bias and Young Massive Cluster Characterisation I. 2D Perspective Effects
• The Spatial Evolution of Young Massive Clusters III. Effect of the Gaia Filter on 2D Spatial Distribution Studies
• Using Molecular Gas Observations to Guide Initial Conditions for Star Cluster Simulations
• Cloud structure and young star distribution in the Dragonfish complex
• Deviations from the universal Initial Mass Function in binary star clusters
• S2D2: Small-scale Significant substructure DBSCAN Detection II. Tracing episodes and gradients of star formation activity