A Larger Extent for the Ophiuchus Stream
A Larger Extent for the Ophiuchus Stream
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DOI：
10.3847/1538-3881/ab8cbf
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发表时间：
2020-04
期刊：
影响因子：
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通讯作者：
N. Caldwell;A. Bonaca;A. Price-Whelan;B. Sesar;M. Walker
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文献类型：
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作者：
N. Caldwell;A. Bonaca;A. Price-Whelan;B. Sesar;M. Walker
我们提出了新的蛇夫座恒星流的运动学数据。在MMT望远镜上使用Hectospec、Hectochelle和Binospec拍摄了候选成员的光谱，提供了1800多个新的速度。结合自行测量的恒星在该领域的盖亚-DR 2目录，我们推导出流成员的概率，导致检测到200多个可能的成员。这些数据显示，流的长度是发现数据中显示的长度的三倍以上。还检测到主流的支线。高分辨率的光谱使我们能够分辨恒星的速度色散，发现为1.6 ± 0.3 km s−1。
We present new kinematic data for the Ophiuchus stellar stream. Spectra have been taken of member candidates at the MMT telescope using Hectospec, Hectochelle, and Binospec, which provide more than 1800 new velocities. Combined with proper-motion measurements of stars in the field by the Gaia—DR2 catalog, we have derived stream membership probabilities, resulting in the detection of more than 200 likely members. These data show the stream extends to more than three times the length shown in the discovery data. A spur to the main stream is also detected. The high-resolution spectra allow us to resolve the stellar velocity dispersion, found to be 1.6 ± 0.3 km s−1.