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arXiv 1406.7645astro-ph.GA
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12个北方红外暗云的物理性质、动力学和质量函数

Physical properties, kinetics and mass function of 12 northern infrared dark clouds

Xiao-Lan Liu, Jun-Jie Wang, Jin-Long Xu

摘要:

利用PMO 13.7 m射电望远镜观测的$\rm ^{13}CO $(1-0)和$\rm C^{18}O$(1-0)谱线、1.1 mm Bolocam银盘巡天(BGPS)资料和GLIMPSE Spitzer IRAC $\rm 8 \,μm$资料,系统研究了12个北方红外暗云的物理、化学和动力学特征。分子线发射和1.1毫米连续发射几乎一致的形态为每个IRDC和两者都与IRDC。10个内陆发展中国家介绍了行政结构和次级结构。共识别出41个IRDC核,对它们的统计研究表明,北部IRDC核具有典型的激发温度$8\sim10$ K、$\rm ^{13}CO$与$\rm C^{18}O$的积分强度比$3\sim6$和柱密度$(1\sim6)\times 10^{22}\, \rm cm^{-2}$。IRDC核中约有$57.5\%$为重力束缚核,它们更致密、更温暖、更致密。此外,我们还研究了整个IRDC核以及引力束缚核的质量分布函数,发现它们几乎具有相同的幂律指数。这表明IRDC核的演化对分子核的质量谱几乎没有影响,可以用来研究恒星的初始质量函数。此外,三个IRDC核心G24.00-3,G31.38-1和G34.43-4被检测到具有大尺度的内陷运动。在IRDC G34.43-4芯进一步发现了两个不同的外流,其中一个是高准直的。

英文摘要:

The physical, chemical and kinetic characteristics of 12 northern infrared dark clouds (IRDCs) are systematic studied using the $\rm ^{13}CO $ (1-0) and $\rm C^{18}O$ (1-0) lines, observed with the PMO 13.7 m radio telescope, the 1.1 mm Bolocam Galactic Plane Survey (BGPS) data and GLIMPSE Spitzer IRAC $\rm 8 \,μm$ data. The molecular lines emission and 1.1 mm continuum emission almost coincide in morphology for each IRDC and both are associated well with the IRDCs. 10 IRDCs present the filamentary structure and substructures. Totally, 41 IRDC cores are identified and a statistic research for them shows that the northern IRDC cores have a typical excitation temperature $8\sim10$ K, a integrated intensity ratio of $\rm ^{13}CO$ to $\rm C^{18}O$ $3\sim6$ and the column density $(1\sim6)\times 10^{22}\, \rm cm^{-2}$. About $57.5\%$ of the IRDC cores are gravitationally bound, which are more compact, warmer and denser. In addition, we study the mass distribution functions of the whole IRDC cores as well as the gravitational bound cores, finding that they almost have the same power-law indexes. This indicates that the evolution of the IRDC cores almost have no effect on the mass spectrum of the molecular cores and thus can be used to study the stellar initial mass function. Moreover, three IRDC cores G24.00-3, G31.38-1 and G34.43-4 are detected to have large-scaled infall motions. Two different outflows are further found for IRDC core G34.43-4 and one of them is in high collimation.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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