Large area mapping at 850 microns. III. Analysis of the clump distribution in the Orion B molecular cloud

被引:163
作者
Johnstone, D [1 ]
Fich, M
Mitchell, GF
Moriarty-Schieven, G
机构
[1] Univ Toronto, Dept Astron, Toronto, ON M5S 3H8, Canada
[2] Univ Waterloo, Dept Phys, Waterloo, ON N2L 3G1, Canada
[3] St Marys Univ, Dept Phys & Astron, Halifax, NS B3H 3C3, Canada
[4] Natl Res Council Canada, Joint Astron Ctr, University Pk, HI 96720 USA
关键词
infrared : ISM : continuum; ISM : clouds; ISM; individual; (HH; 25-26; L1630; NGC; 2068; 2071; Orion B); ISM : molecules; ISM : structure; stars : formation;
D O I
10.1086/322323
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present results from a survey of a 900 arcmin(2) region of the Orion B molecular cloud, including NGC 2068, NGC 2071, and HH 24/25/26, at 850 mum using the Submillimeter Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope. Following the techniques developed by Johnstone et al., we identify 75 independent objects and compute size, flux, and degree of central concentration. Comparison with isothermal, pressure-confined, self-gravitating Bonnor-Ebert spheres implies that the clumps have internal temperatures of 20-40 K and surface pressures 5.5 < log P/k < 6.5. The clump masses span 0.2-12.3 M-circle dot assuming typical dust temperatures and a dust emissivity kappa (850) = 0.01 cm(2) g(-1). The distribution of clump masses is well characterized by a power-law N(M) proportional to M-alpha with alpha = 1.5-2.0 for M > 1.0 M-circle dot. Significant incompleteness makes determination of the slope at lower masses difficult. The two-point correlation function of the clump separations is measured revealing clustering on size scales r < 1.5 x 10(5) AU with a radial power-law exponent <gamma> = 0.75.
引用
收藏
页码:307 / 317
页数:11
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