STAR FORMATION AND DISTRIBUTIONS OF GAS AND DUST IN THE CIRCINUS CLOUD
STAR FORMATION AND DISTRIBUTIONS OF GAS AND DUST IN THE CIRCINUS CLOUD
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马戏团云中恒星的形成以及气体和尘埃的分布
DOI：
10.1088/0004-637x/731/1/23
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
TOMOMI SHIMOIKURA AND KAZUHITO DOBASHI
中科院分区：
文献类型：
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作者：
N.Miura;J. Miyazaki;S. Kuwamura et al;S. Ohta;宮本安人;TOMOMI SHIMOIKURA AND KAZUHITO DOBASHI
我们提出了基于13 CO （J= 1−0）数据以及视觉到近红外（JHK S）消光图的Circinus云研究结果，以研究云周围气体和尘埃的分布。circirus云的全球13co分布首次被揭示，并且云的总分子质量估计为2.5× 104m☉，假设距离为700pc。云团中的两个巨大团块，被称为Circinus-W和Circinus-E，质量为~ 5× 10 3 M☉。这些团块与文献中搜索到的许多年轻恒星物体（yso）有关，表明它们是Circinus中最活跃的恒星形成地点。所有消光图与13co的分布吻合较好。通过将消光图与13co数据进行比较，我们得出Circinus云的平均N (13co)/A V比值为1.25× 10 15 cm−2等。消光图也让我们得以探索环座云的变红规律。我们发现Circinus-W和Circinus-E最密集区域的尘埃特性有明显的变化，可能是由于密集云内部的颗粒生长。在文献中发现的YSOs中，我们试图推断在两个团块中形成的Hα发射线恒星的年龄和质量，发现它们很可能小于1 Myr，在零年龄主序中具有相对较小的质量为> 2 M☉。
We present results of a study on the Circinus cloud based on 13 CO (J= 1− 0) data as well as visual to near-infrared (JHK S) extinction maps, to investigate the distributions of gas and dust around the cloud. The global 13 CO distribution of the Circinus cloud is revealed for the first time, and the total molecular mass of the cloud is estimated to be 2.5× 10 4 M☉ for the assumed distance 700 pc. Two massive clumps in the cloud, called Circinus-W and Circinus-E, have a mass of∼ 5× 10 3 M☉. These clumps are associated with a number of young stellar objects (YSOs) searched for in the literature, indicating that they are the most active star-forming sites in Circinus. All of the extinction maps show good agreement with the 13 CO distribution. We derived the average N (13 CO)/A V ratio in the Circinus cloud to be 1.25× 10 15 cm− 2 mag− 1 by comparing the extinction maps with the 13 CO data. The extinction maps also allowed us to probe into the reddening law over the Circinus cloud. We found that there is a clear change in dust properties in the densest regions of Circinus-W and Circinus-E, possibly due to grain growth in the dense cloud interior. Among the YSOs found in the literature, we attempted to infer the ages and masses of the Hα emission-line stars forming in the two clumps, and found that they are likely to be younger than 1 Myr, having a relatively small mass of≲ 2 M☉ at the zero-age main sequence.