A Large-Scale Survey of NGC 1333
A Large-Scale Survey of NGC 1333
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DOI：
10.1086/510193
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发表时间：
2006-10
期刊：
影响因子：
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通讯作者：
A. Walsh;P. Myers;J. di Francesco;S. Mohanty;T. Bourke;R. Gutermuth;D. Wilner
中科院分区：
文献类型：
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作者：
A. Walsh;P. Myers;J. di Francesco;S. Mohanty;T. Bourke;R. Gutermuth;D. Wilner
我们用BIMA和FCRAO望远镜在11 ‘ × 11 ’的范围内以分辨率~10 " （0.015 pc）在HCO+(1-0)和N2H+(1-0)的跃迁中观测了星团形成复合体NGC 1333。N2H+的发射与亚毫米尘埃连续辐射非常接近，而HCO+的发射在空间上更广泛，也有流出的痕迹。我们已经确定了93个N2H+核心使用丛集查找算法，我们得出N2H+核心质量在0.05和2.5 M☉之间，不确定因素的几个，主要是采用的N2H+丰度。通过与虚质量的比较，我们认为这些N2H+核心中的大多数很可能是被束缚的，即使是在最低质量的情况下，这表明核心不会追踪瞬态结构，并暗示整个质量分布由可能形成恒星的物体组成。我们发现N2H+核心的质量分布类似于场星IMF，这表明IMF被锁定在恒星前的演化阶段。我们发现，与斯皮策红外图像识别的恒星相关的N2H+核心具有平坦的质量分布。这可能是因为低质量的核心在形成恒星时失去了更大一部分质量。即使在这个群集的环境中，我们也没有发现任何证据表明内核相对于它们的低密度环境的弹道运动，尽管这个结论必须保持暂定，直到周围环境以与N2H+相同的高分辨率观察到。
We observed the clustered star forming complex NGC 1333 with the BIMA and FCRAO telescopes in the transitions HCO+(1-0) and N2H+(1-0) over an 11′ × 11′ area with resolution ~10′′ (0.015 pc). The N2H+ emission follows very closely the submillimeter dust continuum emission, while HCO+ emission appears more spatially extended and also traces outflows. We have identified 93 N2H+ cores using the CLUMPFIND algorithm, and we derive N2H+ core masses between 0.05 and 2.5 M☉, with uncertainties of a factor of a few, dominated by the adopted N2H+ abundance. From a comparison with virial masses, we argue that most of these N2H+ cores are likely to be bound, even at the lowest masses, suggesting that the cores do not trace transient structures, and implies the entire mass distribution consists of objects that can potentially form stars. We find that the mass distribution of N2H+ cores resembles the field star IMF, which suggests that the IMF is locked in at the prestellar stage of evolution. We find that the N2H+ cores associated with stars identified from Spitzer infrared images have a flat mass distribution. This might be because lower mass cores lose a larger fraction of their mass when forming a star. Even in this clustered environment, we find no evidence for ballistic motions of the cores relative to their lower density surroundings traced by isotopic CO emission, although this conclusion must remain tentative until the surroundings are observed at the same high resolution as the N2H+.