鲁宾天文台揭示蛇夫座中一个尘埃遮蔽的晕族球状星团
Rubin Observatory Reveals a Dust-Shrouded Halo Globular Cluster in Ophiuchus
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中文总结 AI 辅助
利用鲁宾天文台数据发现银河系卫星 Rubin-GC1，它是一个暗弱致密的球状星团，可能来自人马座吸积事件，展示了鲁宾在尘埃区发现暗弱卫星的能力。
中文摘要 AI 辅助
我们利用 NSF-DOE 维拉·C·鲁宾天文台早期数据预览 2 的数据，报告了银河系卫星 Rubin-GC1（Rubin J1628-1735）的发现。该系统在银心方向 $(l, b) \sim (359^{\circ}, 21^{\circ})$ 处被发现，该区域恒星密度高，前景红化为 $E(B-V) \approx 0.7$。我们同时拟合了 Rubin-GC1 的形态和等时线参数，确定它是一个暗弱（$M_V = -2.4^{+0.5}_{-0.7}$）且致密（$r_{1/2} = 5^{+1}_{-1}$ pc）的银河系卫星，距离为 $D_\odot = 31^{+3}_{-3}$ kpc；其恒星族群的年龄为中等（$\tau=9.2^{+1.2}_{-0.7}$ Gyr），金属丰度中等偏富（$\mathrm{[Fe/H]_{iso}}=-0.73^{+0.04}_{-0.04}$）。综合这些性质表明，Rubin-GC1 很可能是银河系周围球状星团光度函数暗弱尾端的一个星团。我们在 Gaia DR3 中识别出 Rubin-GC1 的独特自行特征，并通过将该系统的 5D 相空间信息与人马座矮椭球星系潮汐流的 $N$ 体模型进行比较，确定 Rubin-GC1 很可能是一个与人马座前导臂相关的吸积星团。Rubin-GC1 的发现凸显了鲁宾天文台在银河系尘埃遮蔽区域揭示暗弱、可分辨卫星的潜力，包括那些塑造了银河系层级并合历史的吸积事件遗迹。
英文摘要
We present the discovery of the Milky Way satellite Rubin-GC1 (Rubin J1628-1735) using data from the NSF-DOE Vera C. Rubin Observatory's Early Data Preview 2. The system was discovered in the direction of the Galactic bulge with $(l, b) \sim (359^{\circ}, 21^{\circ})$ in a region of high stellar density and a foreground reddening of $E(B-V) \approx 0.7$. We simultaneously fit the morphology and isochrone parameters of Rubin-GC1, determining that it is a faint ($M_V = -2.4^{+0.5}_{-0.7}$) and compact ($r_{1/2} = 5^{+1}_{-1}$ pc) Milky Way satellite at a distance of $D_\odot = 31^{+3}_{-3}$ kpc; its stellar population is intermediate-age ($τ=9.2^{+1.2}_{-0.7}$ Gyr) and moderately metal-rich ($\mathrm{[Fe/H]_{iso}}=-0.73^{+0.04}_{-0.04}$). Together, these properties suggest Rubin-GC1 is most likely a star cluster in the faint tail of the luminosity function of globular clusters surrounding the Milky Way. We identify a distinct proper motion signature from Rubin-GC1 in Gaia DR3, and from a comparison of the system's 5D phase space information to $N$-body models of the Sagittarius dwarf spheroidal galaxy's tidal stream, we determine that Rubin-GC1 is likely an accreted cluster associated with the Sagittarius leading arm. The discovery of Rubin-GC1 highlights the potential of Rubin to uncover faint, resolved satellites in dust-shrouded regions of the Milky Way, including remnants of the accretion events that have shaped the Galaxy's hierarchical assembly.
发表机构
- University of Chicago（芝加哥大学）
- Yale University（耶鲁大学）
- University of Virginia（弗吉尼亚大学）
- Fermi National Accelerator Laboratory（费米国家加速器实验室）
- University of Washington（华盛顿大学）
机构由 AI 辅助整理，请以论文原文为准。
