The Pristine survey - III. Spectroscopic confirmation of an efficient search for extremely metal-poor stars
The Pristine survey - III. Spectroscopic confirmation of an efficient search for extremely metal-poor stars
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DOI：
10.1093/mnras/stx2005
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发表时间：
2017-08
影响因子：
4.8
通讯作者：
K. Youakim;E. Starkenburg;D. Aguado;D. Aguado;N. Martin;N. Martin;M. Fouesneau;J. I. G. Hernández;J. I. G. Hernández;C. A. Prieto;C. A. Prieto;P. Bonifacio;M. Gentile;C. Kielty;P. Cot'e;P. Jablonka;A. McConnachie;R. S. Janssen;E. Tolstoy;K. Venn
中科院分区：
文献类型：
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作者：
K. Youakim;E. Starkenburg;D. Aguado;D. Aguado;N. Martin;N. Martin;M. Fouesneau;J. I. G. Hernández;J. I. G. Hernández;C. A. Prieto;C. A. Prieto;P. Bonifacio;M. Gentile;C. Kielty;P. Cot'e;P. Jablonka;A. McConnachie;R. S. Janssen;E. Tolstoy;K. Venn
纯净巡天是一项窄带光度巡天，聚焦于Ca II HK吸收线的波长区域，旨在有效地寻找极度缺乏金属的恒星。在这项工作中，我们使用中分辨率光谱跟踪的第一个结果来完善在质朴巡天中寻找极贫金属恒星（[Fe/H] <= -3.0）的选择标准。我们考虑了可以从可用的宽带和红外测光以及额外的原始窄带测光中选择恒星的方法。该样本由205颗恒星组成，星等范围为14 < V < 18。应用光度选择标准将样本减少到149颗恒星，从这些中，我们报告发现[Fe/H] = -2.5的恒星成功率为70%，[Fe/H] = -3.0的恒星成功率为22%。这些统计数据与其他寻找金属含量极低的恒星的调查相比是有利的，也就是说，对于[Fe/H] = -3.0的恢复恒星，其改善系数类似于4 - 5。此外，“纯净号”覆盖的星等范围比它的前辈要小，因此可以更深入地探测银河晕。
The Pristine survey is a narrow-band, photometric survey focused around the wavelength region of the Ca II HK absorption lines, designed to efficiently search for extremely metal-poor stars. In this work, we use the first results of amedium-resolution spectroscopic follow-up to refine the selection criteria for finding extremely metal-poor stars ([Fe/H] <= -3.0) in the Pristine survey. We consider methods by which stars can be selected from available broad-band and infrared photometry plus the additional Pristine narrow-band photometry. The sample consists of 205 stars in the magnitude range 14 < V < 18. Applying the photometric selection criteria cuts the sample down to 149 stars, and from these we report a success rate of 70 per cent for finding stars with [Fe/H] = -2.5 and 22 per cent for finding stars with [Fe/H] = -3.0. These statistics compare favourably with other surveys that search for extremely metal-poor stars, namely an improvement by a factor of similar to 4 - 5 for recovering stars with [Fe/H] = -3.0. In addition, Pristine covers a fainter magnitude range than its predecessors and can thus probe deeper into the Galactic halo.