A SPITZER SURVEY OF YOUNG STELLAR CLUSTERS WITHIN ONE KILOPARSEC OF THE SUN: CLUSTER CORE EXTRACTION AND BASIC STRUCTURAL ANALYSIS

摘要: We present a uniform mid-infrared imaging and photometric survey of 36 young, nearby, star-forming clusters groups using Spitzer IRAC MIPS. have confidently identified classified 2548 young stellar objects (YSOs) recently established color-based methods. devised applied new algorithm for the isolation local surface density enhancements from point source distributions, enabling us to extract overdense cores observed regions further analysis. compiled several basic structural measurements these cluster data, such as mean densities sources, core radii, aspect ratios, in order characterize ranges quantities. find that typical is 0.39 pc radius, has 26 members with infrared excess ratio Class II I sources 3.7, embedded A{sub K} = 0.8 mag cloud clump, 60 pc{sup -2}. examine nearest neighbor distances among YSOs ways, demonstrating similarity spacings between but large member appear more dense than smaller clusters. demonstrate near-uniform spacingsmore » are common, suggesting simple Jeans fragmentation parsec-scale clumps may be dominant process governing star formation nearby groups. Finally, we compare our results other similar surveys literature discuss potential biases data guide interpretation.« less