Identification of Main-Sequence Stars with Mid-Infrared Excesses Using GLIMPSE: β Pictoris Analogs?
Identification of Main-Sequence Stars with Mid-Infrared Excesses Using GLIMPSE: β Pictoris Analogs?
复制标题
使用 GLIMPSE 识别中红外过量的主序星：β Pictoris 类似物？
DOI：
10.1086/431479
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Barbara A. Whitney
中科院分区：
文献类型：
--
作者：
B. Uzpen;H. Kobulnicky;D. Clemens;Barbara A. Whitney
Spitzer IRAC 3.6-8 μm光度测量作为GLIMPSE巡天的一部分，揭示了位于银河系H区南部RCW 49的1.2°2场中33颗已知光谱类型的场星的中红外过剩。这些恒星组成了已知光谱分类的184颗恒星的一个子集，其中大多数被预选为具有不寻常的红色红外颜色。我们提出，中红外过量是由星周尘埃盘引起的，这些尘埃盘要么是恒星形成非常晚的残余物，要么是行星形成时产生的碎片盘。在这33颗恒星中，根据光谱分类，29颗似乎是主序星。在29颗主序星中，有5颗是O星或B星，它们的过量可以用热轫致辐射合理地解释，还有4颗是后主序星。唯一的O星是o4v ((f))，在分光光度距离为3233 pc，可能是Westerlund 2星团中最早的成员。在剩下的24颗主序星中，有18颗的光谱能量分布与热尘埃碎片盘一致，这可能是行星形成的标志。对黑体的模拟表明，黑体组成部分的盘星亮度比（LIR/L*）在温度为220至820 K的情况下，从10-3到10-2不等。推断出的温度更符合小行星带，而不是柯伊伯带的较低温度。在从B晚期到K早期的所有光谱类型中都发现了中红外过量。
Spitzer IRAC 3.6-8 μm photometry obtained as part of the GLIMPSE survey has revealed mid-infrared excesses for 33 field stars with known spectral types in a 1.2 deg2 field centered on the southern Galactic H II region RCW 49. These stars comprise a subset of 184 stars with known spectral classification, most of which were preselected to have unusually red IR colors. We propose that the mid-IR excesses are caused by circumstellar dust disks that are either very late remnants of stellar formation or debris disks generated by planet formation. Of these 33 stars, 29 appear to be main-sequence stars on the basis of optical spectral classifications. Five of the 29 main-sequence stars are O or B stars with excesses that can be plausibly explained by thermal bremsstrahlung emission, and four are post-main-sequence stars. The lone O star is an O4 V((f)) at a spectrophotometric distance of 3233 pc and may be the earliest member of the Westerlund 2 cluster. Of the remaining 24 main-sequence stars, 18 have spectral energy distributions that are consistent with hot dusty debris disks, a possible signature of planet formation. Modeling the excesses as blackbodies demonstrates that the blackbody components have fractional bolometric disk-to-star luminosity ratios, LIR/L*, ranging from 10-3 to 10-2 with temperatures ranging from 220 to 820 K. The inferred temperatures are more consistent with asteroid belts than with the cooler temperatures expected for Kuiper belts. Mid-IR excesses are found in all spectral types from late B to early K.
影响因子：
3.2
作者：
V. Mannings;A. Boss;S. Russell
通讯作者：
V. Mannings;A. Boss;S. Russell