Mass segregation and sequential star formation in NGC 2264 revealed by Herschel

Abstract

The mass segregation of stellar clusters could be primordial rather than dynamical. Despite the abundance of studies of mass segregation for stellar clusters, those for stellar progenitors are still scarce, so the question on the origin and evolution of mass segregation is still open. Our goal is to characterize the structure of the NGC 2264 molecular cloud and compare the populations of clumps and young stellar objects (YSOs) in this region whose rich YSO population has shown evidence of sequential star formation. We separated the Herschel column density map of NGC 2264 in three subregions and compared their cloud power spectra using a multiscale segmentation technique. We identified in the whole NGC 2264 cloud a population of 256 clumps with typical sizes of ~0.1 pc and masses ranging from 0.08 Msun to 53 Msun. Although clumps have been detected all over the cloud, the central subregion of NGC 2264 concentrates most of the massive, bound clumps. The local surface density and the mass segregation ratio indeed indicate a strong degree of mass segregation for the 15 most massive clumps, with a median ${\Sigma }_6$ three time that of the whole clumps population and ${\Lambda }_{MSR}$ about 8. We showed that this cluster of massive clumps is forming within a high-density cloud ridge, itself formed and probably still fed by the high concentration of gas observed on larger scales in the central subregion. The time sequence obtained from the combined study of the clump and YSO populations in NGC 2264 suggests that the star formation started in the northern subregion, that it is now actively developing at the center and will soon start in the southern subregion. Taken together, the cloud structure and the clump and YSO populations in NGC 2264 argue for a dynamical scenario of star formation.

26 pages, 19 figures. Accepted for publication in A&A, abstract abridged for arXiv

References in corpus (17)

• A Spitzer Survey of Young Stellar Clusters within One Kiloparsec of the Sun: Cluster Core Extraction and Basic Structural Analysis
• Filamentary structure of star-forming complexes
• Using the minimum spanning tree to trace mass segregation
• Cooling, Gravity and Geometry: Flow-driven Massive Core Formation
• The Spatial Structure of Young Stellar Clusters. I. Subclusters
• Properties of the dense core population in Orion B as seen by the Herschel Gould Belt survey
• Structure and mass segregation in Galactic stellar clusters
• No evidence for mass segregation in massive young clusters
• Comparisons between different techniques for measuring mass segregation
• The Gaia-ESO Survey and CSI 2264: Substructures, disks, and sequential star formation in the young open cluster NGC 2264
• Herschel Observations of the W3 GMC: Clues to the Formation of Clusters of High-Mass Stars
• Physical Properties of the star-forming clusters in NGC 6334
• The JCMT Gould Belt Survey: Dense Core Clusters in Orion A
• A Spitzer View of Mon OB1 East/NGC 2264
• Far-infrared observations of a massive cluster forming in the Monoceros R2 filament hub
• Statistical model for filamentary structures of molecular clouds -- The modified multiplicative random cascade model and its multifractal nature
• Background derivation and image flattening: getimages

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