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arXiv 2312.06201astro-ph.GAastro-ph.SR
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基于 LAMOST DR7 的碳星证认

Identification of Carbon Stars from LAMOST DR7

Linlin Li, Kecheng Zhang, Wenyuan Cui, Jianrong Shi, Wei Ji, Zhenyan Huo, Yawei Gao, Shuai Zhang, Mingxu Sun

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AI总结：

该研究利用谱线指数、近红外双色图和目视检查从 LAMOST DR7 中证认出 3546 颗碳星并完成子分类，结合 Gaia 距离识别矮碳星并分析其空间分布。

摘要：

碳星是研究星系运动学的极佳示踪天体，对理解银河系演化具有重要作用。因此，在海量光谱中搜寻碳星很有价值。本工作基于 LAMOST DR7 光谱构建了一个新的碳星星表。该星表包含 3546 颗碳星的 4542 条光谱，通过谱线指数和近红外双色图进行证认。通过对光谱的目视检查，我们进一步将它们细分为 925 颗 C-H 星、384 颗 C-R 星、608 颗 C-N 星和 1292 颗 Ba 星。但有 437 颗星因信噪比过低而无法进行子分类。此外，通过与 LAMOST DR7 流水线结果比较，我们发现了另外 567 颗碳星并对其进行了目视子分类。我们发现，在 J-H 与 H-K_s 双色图上，C-N 星能够可靠地与其他三个子型区分开。另外，利用 Gaia 距离，我们研究了碳星在赫罗图上的分布，并依据 M_G > 5.0 mag 的判据证认出 258 颗矮碳星。最后，我们给出了这 3546 颗碳星在银道坐标中的空间分布。大多数 C-N、C-R 和 Ba 星分布在低银纬区域，而大多数 C-H 星和 dC 星则分布在高银纬区域。

英文摘要：

Carbon stars are excellent kinematic tracers of galaxies and play important roles in understanding the evolution of the Galaxy. Therefore, it is worthwhile to search for them in a large amount of spectra. In this work, we build a new carbon star catalog based on the LAMOST DR7 spectra. The catalog contains 4542 spectra of 3546 carbon stars, identified through line index and near-infrared color-color diagrams. Through visual inspection of the spectra, we further subclassify them into 925 C--H, 384 C--R, 608 C--N, and 1292 Ba stars. However, 437 stars could not be sub-classified due to their low signal-to-noise. Moreover, by comparing with LAMOST DR7 pipeline we find 567 more carbon stars and visually sub-classify them. We find that on the $J-H$ vs. $H-K_{\rm s}$ two-color diagram, C--N stars can be reliably distinguished from the other three sub-types. Additionally, by utilizing the Gaia distance, we study the distribution of carbon stars in the H-R diagram and identify 258 dwarf carbon stars by the criterion $M_{\rm G}>$5.0\,mag. Finally, we present the spatial distribution in Galactic coordinates of the 3546 carbon stars. The majority of C-N, C-R, and Ba stars are distributed at low Galactic latitudes, while most C--H and dC stars distribute at high Galactic latitudes.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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