CARMENES input catalogue of M dwarfs. I. Low-resolution spectroscopy with CAFOS
CARMENES input catalogue of M dwarfs. I. Low-resolution spectroscopy with CAFOS
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DOI：
10.1051/0004-6361/201525803
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发表时间：
2015-02
期刊：
影响因子：
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通讯作者：
F. J. Alonso-Floriano;J. Morales;J. Morales;J. Caballero;D. Montes;A. Klutsch;A. Klutsch;R. Mundt;M. Cortés-Contreras;I. Ribas;A. Reiners;P. Amado;A. Quirrenbach;S. Jeffers
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文献类型：
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作者：
F. J. Alonso-Floriano;J. Morales;J. Morales;J. Caballero;D. Montes;A. Klutsch;A. Klutsch;R. Mundt;M. Cortés-Contreras;I. Ribas;A. Reiners;P. Amado;A. Quirrenbach;S. Jeffers
语境。 CARMENES 是一台稳定的高分辨率双通道摄谱仪，安装在 3.5 m Calar Alto 望远镜上。它经过优化设计，用于对具有潜在宜居地球质量行星的 M 矮星进行径向速度调查。目标。我们准备了一份北半球可观测到的每种光谱亚型中最亮的单一 M 型矮星的列表，我们将从中为卡门尼斯选择最佳的行星搜寻目标。方法。在第一篇关于准备输入星表的论文中，我们汇编了大量公共数据，并使用 CAFOS 在 2.2 m Calar Alto 望远镜上收集了 753 颗恒星的低分辨率光谱。我们使用标准恒星的密集网格、双最小二乘最小化技术以及其他作者先前定义的 31 个光谱指数得出了准确的光谱类型。此外，我们还量化了样本中所有恒星的表面重力、金属丰度和色球活动。结果。我们计算了所有 753 颗恒星的光谱类型，其中 305 颗是新星，448 颗是修改过的。我们测量了样本中所有恒星的 Hα 伪当量宽度，得出结论，色球活动不会影响我们指数的光谱分类，并列出了 49 颗据报道为疏散星团、移动星团和恒星协会中的年轻恒星的恒星。在这 753 颗恒星中，两颗是新的亚矮星候选星，三颗是金牛座 T 星，25 颗是巨星，44 颗是 K 矮星，679 颗是 M 矮星。在 M4.0-8.0 V 范围内研究的 261 颗矮星中，许多都是其光谱亚型中已知最亮的恒星。结论。这些低分辨率光谱数据可以作为 CARMENES 巡天的候选目标列表，对于 M 矮星的其他径向速度巡天以及太阳附近冷矮星的研究非常有价值。
Context. CARMENES is a stabilised, high-resolution, double-channel spectrograph at the 3.5 m Calar Alto telescope. It is optimally designed for radial-velocity surveys of M dwarfs with potentially habitable Earth-mass planets. Aims. We prepare a list of the brightest, single M dwarfs in each spectral subtype observable from the northern hemisphere, from which we will select the best planet-hunting targets for CARMENES. Methods. In this first paper on the preparation of our input catalogue, we compiled a large amount of public data and collected low-resolution optical spectroscopy with CAFOS at the 2.2 m Calar Alto telescope for 753 stars. We derived accurate spectral types using a dense grid of standard stars, a double least-squares minimisation technique, and 31 spectral indices previously defined by other authors. Additionally, we quantified surface gravity, metallicity, and chromospheric activity for all the stars in our sample. Results. We calculated spectral types for all 753 stars, of which 305 are new and 448 are revised. We measured pseudo-equivalent widths of Halpha for all the stars in our sample, concluded that chromospheric activity does not affect spectral typing from our indices, and tabulated 49 stars that had been reported to be young stars in open clusters, moving groups, and stellar associations. Of the 753 stars, two are new subdwarf candidates, three are T Tauri stars, 25 are giants, 44 are K dwarfs, and 679 are M dwarfs. Many of the 261 investigated dwarfs in the range M4.0-8.0 V are among the brightest stars known in their spectral subtype. Conclusions. This collection of low-resolution spectroscopic data serves as a candidate target list for the CARMENES survey and can be highly valuable for other radial-velocity surveys of M dwarfs and for studies of cool dwarfs in the solar neighbourhood.