Chemical abundances of seven stars in the GD-1 stream
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| Main Authors: | , , , , , , , , , , , , , , , |
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| Format: | Preprint |
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2025
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| _version_ | 1866911087364931584 |
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| author | Zhao, Jing-Kun Li, Guang-Wei Aoki, Wako Zhao, Gang Yang, Guo-Chao Shi, Jian-Rong Li, Hai-Ning Matsuno, Tadafumi Ishigaki, Miho Suda, Takuma Honda, Satoshi Chen, Yu-Qin Xing, Qian-Fan Yan, Hong-Liang Yang, Yong Ye, Xian-Hao |
| author_facet | Zhao, Jing-Kun Li, Guang-Wei Aoki, Wako Zhao, Gang Yang, Guo-Chao Shi, Jian-Rong Li, Hai-Ning Matsuno, Tadafumi Ishigaki, Miho Suda, Takuma Honda, Satoshi Chen, Yu-Qin Xing, Qian-Fan Yan, Hong-Liang Yang, Yong Ye, Xian-Hao |
| contents | We present the first detailed chemical abundances for seven GD-1 stream stars from Subaru/HDS spectroscopy. Atmospheric parameters were derived via color calibrations ($T\rm_{eff}$) and iterative spectroscopic analysis. LTE abundances for 14 elements ($α$, odd-Z, iron-peak, n-capture) were measured. Six stars trace the main orbit, one resides in a `blob'. All exhibit tightly clustered metallicities ([Fe/H] = -2.38, {\bf intrinsic dispersion smaller than 0.05 dex, average uncertainty is about 0.13 dex}). While one star shows binary mass transfer signatures, the other six display consistent abundance patterns (dispersions $<$ uncertainties). Their iron-peak elements (Sc, Cr, Mn, Ni) match Milky Way halo stars. In contrast, Y and Sr are systematically lower than halo stars of similar [Fe/H]. Significantly, six stars show consistently enhanced [Eu/Fe] $\sim$ 0.60 ($σ$ = 0.08). A tight Ba-Eu correlation (r = 0.83, p=0.04) exists, with [Ba/Fe] = -0.03 $\pm$ 0.05, indicating a common r-process origin. This extreme chemical homogeneity strongly supports an origin from a single disrupted globular cluster. The lack of light-element anti-correlations may stem from our sample size or the progenitor's low mass. |
| format | Preprint |
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arxiv_https___arxiv_org_abs_2508_00671 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Chemical abundances of seven stars in the GD-1 stream Zhao, Jing-Kun Li, Guang-Wei Aoki, Wako Zhao, Gang Yang, Guo-Chao Shi, Jian-Rong Li, Hai-Ning Matsuno, Tadafumi Ishigaki, Miho Suda, Takuma Honda, Satoshi Chen, Yu-Qin Xing, Qian-Fan Yan, Hong-Liang Yang, Yong Ye, Xian-Hao Astrophysics of Galaxies We present the first detailed chemical abundances for seven GD-1 stream stars from Subaru/HDS spectroscopy. Atmospheric parameters were derived via color calibrations ($T\rm_{eff}$) and iterative spectroscopic analysis. LTE abundances for 14 elements ($α$, odd-Z, iron-peak, n-capture) were measured. Six stars trace the main orbit, one resides in a `blob'. All exhibit tightly clustered metallicities ([Fe/H] = -2.38, {\bf intrinsic dispersion smaller than 0.05 dex, average uncertainty is about 0.13 dex}). While one star shows binary mass transfer signatures, the other six display consistent abundance patterns (dispersions $<$ uncertainties). Their iron-peak elements (Sc, Cr, Mn, Ni) match Milky Way halo stars. In contrast, Y and Sr are systematically lower than halo stars of similar [Fe/H]. Significantly, six stars show consistently enhanced [Eu/Fe] $\sim$ 0.60 ($σ$ = 0.08). A tight Ba-Eu correlation (r = 0.83, p=0.04) exists, with [Ba/Fe] = -0.03 $\pm$ 0.05, indicating a common r-process origin. This extreme chemical homogeneity strongly supports an origin from a single disrupted globular cluster. The lack of light-element anti-correlations may stem from our sample size or the progenitor's low mass. |
| title | Chemical abundances of seven stars in the GD-1 stream |
| topic | Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2508.00671 |