THE MAGELLANIC MOPRA ASSESSMENT (MAGMA). I. THE MOLECULAR CLOUD POPULATION OF THE LARGE MAGELLANIC CLOUD
THE MAGELLANIC MOPRA ASSESSMENT (MAGMA). I. THE MOLECULAR CLOUD POPULATION OF THE LARGE MAGELLANIC CLOUD
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DOI：
10.1088/0067-0049/197/2/16
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发表时间：
2011-08
期刊：
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通讯作者：
T. Wong;A. Hughes;J. Ott;E. Muller;J. Pineda;J. Bernard;Y. Chu;Y. Fukui;R. Gruendl;C. Henkel;A. Kawamura;U. Klein;L. Looney;S. Maddison;Y. Mizuno;D. Paradis;J. Seale;Daniel E. Welty U. of Illinois;Usa;U. Swinburne;Australia.;Cass;Mpia;Heidelberg;H Germany;Nrao;U. Nagoya;Japan.;Naoj;Jpl;Irap;Toulouse;France.;Mpifr;Bonn;U. KingAbdulaziz;S. Arabia;AIfA;Stsci
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文献类型：
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作者：
T. Wong;A. Hughes;J. Ott;E. Muller;J. Pineda;J. Bernard;Y. Chu;Y. Fukui;R. Gruendl;C. Henkel;A. Kawamura;U. Klein;L. Looney;S. Maddison;Y. Mizuno;D. Paradis;J. Seale;Daniel E. Welty U. of Illinois;Usa;U. Swinburne;Australia.;Cass;Mpia;Heidelberg;H Germany;Nrao;U. Nagoya;Japan.;Naoj;Jpl;Irap;Toulouse;France.;Mpifr;Bonn;U. KingAbdulaziz;S. Arabia;AIfA;Stsci
我们提出的大麦哲伦云（LMC）的分子云在CO（1-0）线映射在11 pc分辨率的广泛样本的属性。根据NANTEN调查测量的限制CO通量和峰值亮度选择目标。这些观测是使用ATNF Mopra望远镜进行的，作为麦哲伦Mopra评估的一部分。我们确定云连接CO排放的区域，并发现云的大小，通量和质量的分布是敏感的分解参数的选择。然而，在所有情况下，CO云的光度函数都比dN/dL <$L−2陡峭，这表明相当大一部分质量是在低质量的云中。尺寸和线宽之间的相关性，而明显的最大的发射结构，打破了当这些结构被分解成较小的结构。我们认为，维里质量和CO光度之间的相关性是比较两个协变量的结果，与相关性出现更紧密的尺寸线宽关系持有的较大尺度。维里参数（云的动能与自引力能的比值）显示了一个很宽的值范围，并且没有表现出与CO光度或年轻恒星天体（YSO）候选者的可能性的明显趋势，这进一步怀疑了大麦哲伦星云中分子云维里化的假设。更高的CO光度增加了云窝藏YSO候选者的可能性，更明亮的YSO更有可能与可检测到的CO发射相一致，证实了巨大分子云和大质量星星形成之间的密切联系。
We present the properties of an extensive sample of molecular clouds in the Large Magellanic Cloud (LMC) mapped at 11 pc resolution in the CO(1–0) line. Targets were chosen based on a limiting CO flux and peak brightness as measured by the NANTEN survey. The observations were conducted with the ATNF Mopra Telescope as part of the Magellanic Mopra Assessment. We identify clouds as regions of connected CO emission and find that the distributions of cloud sizes, fluxes, and masses are sensitive to the choice of decomposition parameters. In all cases, however, the luminosity function of CO clouds is steeper than dN/dL∝L−2, suggesting that a substantial fraction of mass is in low-mass clouds. A correlation between size and linewidth, while apparent for the largest emission structures, breaks down when those structures are decomposed into smaller structures. We argue that the correlation between virial mass and CO luminosity is the result of comparing two covariant quantities, with the correlation appearing tighter on larger scales where a size–linewidth relation holds. The virial parameter (the ratio of a cloud's kinetic to self-gravitational energy) shows a wide range of values and exhibits no clear trends with the CO luminosity or the likelihood of hosting young stellar object (YSO) candidates, casting further doubt on the assumption of virialization for molecular clouds in the LMC. Higher CO luminosity increases the likelihood of a cloud harboring a YSO candidate, and more luminous YSOs are more likely to be coincident with detectable CO emission, confirming the close link between giant molecular clouds and massive star formation.