Mass distributions of stars and cores in young groups and clusters

Abstract

We investigate the relation of the stellar initial mass function (IMF) and the dense core mass function (CMF), using stellar masses and positions in 14 well-studied young groups. Initial column density maps are computed by replacing each star with a model initial core having the same star formation efficiency (SFE). For each group the SFE, core model, and observational resolution are varied to produce a realistic range of initial maps. A clumpfinding algorithm parses each initial map into derived cores, derived core masses, and a derived CMF. The main result is that projected blending of initial cores causes derived cores to be too few and too massive. The number of derived cores is fewer than the number of initial cores by a mean factor 1.4 in sparse groups and 5 in crowded groups. The mass at the peak of the derived CMF exceeds the mass at the peak of the initial CMF by a mean factor 1.0 in sparse groups and 12.1 in crowded groups. These results imply that in crowded young groups and clusters, the mass distribution of observed cores may not reliably predict the mass distribution of protostars which will form in those cores.

48 pages, 17 figures, accepted for publication in Astrophysical Journal

References in corpus (14)

• Power-law distributions in empirical data
• A Spitzer Survey of Young Stellar Clusters within One Kiloparsec of the Sun: Cluster Core Extraction and Basic Structural Analysis
• The Stellar Population of the Chamaeleon I Star-Forming Region
• Bolocam Survey for 1.1 mm Dust Continuum Emission in the c2d Legacy Clouds. II. Ophiuchus
• 2MASS wide field extinction maps - I. The Pipe nebula
• The Large and Small Scale Structures of Dust in the Star-Forming Perseus Molecular Cloud
• A SCUBA survey of Orion, the low-mass end of the core mass function
• A Spitzer census of the IC 348 nebula
• The Perils of Clumpfind: The Mass Spectrum of Sub-structures in Molecular Clouds
• The relationship between the prestellar core mass function and the stellar initial mass function
• Massive Clumps in the NGC 6334 Star Forming Region
• On the Evolution of the Dense Core Mass Function
• On the fidelity of the core mass functions derived from dust column density data
• Massive Quiescent Cores in Orion. -- II. Core Mass Function

Cited by in corpus (6)

• Connecting the Dots: Analyzing Synthetic Observations of Star-Forming Clumps in Molecular Clouds
• The Dependence of Prestellar Core Mass Distributions on the Structure of the Parental Cloud
• Source clustering in the Hi-GAL survey determined using a minimum spanning tree method
• A complete data frame work for fitting power law distributions
• Searching for initial mass function variations in resolved stellar populations
• Speeding up lower bound estimation in powerlaw distributions