MYStIX First Results: Spatial Structures of Massive Young Stellar Clusters

TL;DR

This paper analyzes the spatial distributions of young stars in star-forming regions from the MYStIX project, revealing diverse clustering structures, subclusters, and mass segregation patterns using statistical methods.

Contribution

It introduces a comprehensive analysis of young stellar cluster structures using multiple statistical tools, providing new insights into star formation processes.

Findings

Diverse cluster structures and subclustering observed.

Mass segregation detected in several clusters.

Some clusters show no mass segregation.

Abstract

Observations of the spatial distributions of young stars in star-forming regions can be linked to the theory of clustered star formation using spatial statistical methods. The MYStIX project provides rich samples of young stars from the nearest high-mass star-forming regions. Maps of stellar surface density reveal diverse structure and subclustering. Young stellar clusters and subclusters are fit with isothermal spheres and ellipsoids using the Bayesian Information Criterion to estimate the number of subclusters. Clustering is also investigated using Cartwright and Whitworth's Q statistic and the inhomogeneous two-point correlation function. Mass segregation is detected in several cases, in both centrally concentrated and fractally structured star clusters, but a few clusters are not mass segregated.