SPITZER IMAGING OF THE NEARBY RICH YOUNG CLUSTER, Cep OB3b
SPITZER IMAGING OF THE NEARBY RICH YOUNG CLUSTER, Cep OB3b
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DOI：
10.1088/0004-637x/750/2/125
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发表时间：
2012-03
期刊：
影响因子：
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通讯作者：
T. Allen;R. Gutermuth;E. Kryukova;S. Thomas Megeath;J. Pipher;T. Naylor;R. Jeffries;S. Wolk;B. Spitzbart;J. Muzerolle
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文献类型：
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作者：
T. Allen;R. Gutermuth;E. Kryukova;S. Thomas Megeath;J. Pipher;T. Naylor;R. Jeffries;S. Wolk;B. Spitzbart;J. Muzerolle
我们映射的全部范围内的一个丰富的大规模的年轻集群在Cep OB 3b协会与红外阵列相机和多波段成像光度计系统仪器搭载斯皮策太空望远镜和ACIS仪器搭载钱德拉X射线天文台。在700 pc时，它被发现是第二个最近的大型（>1000成员），年轻（<500万年）的星团。与最近的大型星团猎户座星云相比，Cep OB 3b只有轻微的模糊，并且大部分位于周围分子云雕刻出来的一个大空腔中。我们的红外和X射线数据集，以及从文献可见光光度，是用来采取普查的年轻恒星在Cep OB 3b。我们发现，在集群内的年轻恒星集中在两个子集群;东部子集群，附近的Cep B分子团，和西部子集群，附近的Cep F分子团。使用我们的年轻恒星的普查，我们研究的年轻恒星的红外线过剩的星周盘指示的分数。我们创建了一个地图的磁盘分数在整个集群，并发现它是空间可变的。由于这些空间变化，两个子集群表现出彼此显著不同的平均磁盘分数：32% ± 4%和50% ± 6%。我们讨论是否差异磁盘分数是由于光盘的集群的高质量成员的光破坏，或者它们是否导致子集群的年龄差异。我们的结论是，差异磁盘分数最有可能是由于年龄的差异。
We map the full extent of a rich massive young cluster in the Cep OB3b association with the Infrared Array Camera and Multi-band Imaging Photometer System instruments aboard the Spitzer Space Telescope and the ACIS instrument aboard the Chandra X-Ray Observatory. At 700 pc, it is revealed to be the second nearest large (>1000 member), young (<5 Myr) cluster known. In contrast to the nearest large cluster, the Orion Nebula Cluster, Cep OB3b is only lightly obscured and is mostly located in a large cavity carved out of the surrounding molecular cloud. Our infrared and X-ray data sets, as well as visible photometry from the literature, are used to take a census of the young stars in Cep OB3b. We find that the young stars within the cluster are concentrated in two sub-clusters; an eastern sub-cluster, near the Cep B molecular clump, and a western sub-cluster, near the Cep F molecular clump. Using our census of young stars, we examine the fraction of young stars with infrared excesses indicative of circumstellar disks. We create a map of the disk fraction throughout the cluster and find that it is spatially variable. Due to these spatial variations, the two sub-clusters exhibit substantially different average disk fractions from each other: 32% ± 4% and 50% ± 6%. We discuss whether the discrepant disk fractions are due to the photodestruction of disks by the high mass members of the cluster or whether they result from differences in the ages of the sub-clusters. We conclude that the discrepant disk fractions are most likely due to differences in the ages.