THE DISK POPULATION OF THE UPPER SCORPIUS ASSOCIATION
THE DISK POPULATION OF THE UPPER SCORPIUS ASSOCIATION
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DOI：
10.1088/0004-637x/758/1/31
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发表时间：
2012-09
期刊：
影响因子：
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通讯作者：
K. Luhman;E. Mamajek
中科院分区：
文献类型：
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作者：
K. Luhman;E. Mamajek
我们根据斯皮策太空望远镜和广域红外巡天探测器获得的所有这些天体的图像，对所有已知的上天蝎座成员（τ ~ 11 Myr）进行了3-24 μm的光度测定。我们利用这些数据来确定那些表现出来自星周盘的过量辐射的成员，并估计这些盘的演化阶段。通过这一分析，我们发现了大约50个新的过渡、演化和碎片盘候选者。对于B-G恒星（M > 1.2 M☉），拥有内部原始盘的成员的比例为> 10%，而在> M5 （M > 0.2 M☉）的成员中，这一比例增加到约25%，这与之前对上Sco成员的较小样本的盘调查结果一致。这些数据表明，低质量恒星盘的寿命较长，而且相当一部分低质量恒星盘的寿命至少为10 Myr。最后，我们证明了上Sco和更年轻的金牛座恒星形成区（τ ~ 1 Myr）的超大尺寸分布与清除内部盘的相同的短暂时间尺度是一致的。
We present photometry at 3–24 μm for all known members of the Upper Scorpius association (τ ∼ 11 Myr) based on all images of these objects obtained with the Spitzer Space Telescope and the Wide-field Infrared Survey Explorer. We have used these data to identify the members that exhibit excess emission from circumstellar disks and estimate the evolutionary stages of these disks. Through this analysis, we have found ∼50 new candidates for transitional, evolved, and debris disks. The fraction of members harboring inner primordial disks is ≲ 10% for B–G stars (M > 1.2 M☉) and increases with later types to a value of ∼25% at ≳M5 (M ≲ 0.2 M☉), in agreement with the results of previous disk surveys of smaller samples of Upper Sco members. These data indicate that the lifetimes of disks are longer at lower stellar masses and that a significant fraction of disks of low-mass stars survive for at least ∼10 Myr. Finally, we demonstrate that the distribution of excess sizes in Upper Sco and the much younger Taurus star-forming region (τ ∼ 1 Myr) is consistent with the same, brief timescale for clearing of inner disks.