论文标题
Lamost J1109+7459的起源
The Origin of LAMOST J1109+7459
论文作者
论文摘要
我们报告了Lamost J1109+0754的全面化学动力分析，相对较好（v = 12.8），极为金属罚款（[Fe/H] = $ -3.17 $）和PROGRADE（$ J_ ϕ $和$ v_D $和$ v_D_ $> 0 $），带有强\ textit \ textit \ textit \ textit {$+emhants（e+）。 $ \ pm $ 0.12，[ba/fe] = $ - $ 0.52 $ \ pm $ 0.15）。衍生出31个化学丰度（从锂到th）。我们建议一个可能的祖先，其出色质量为13.4-29.5 m $ _ \ odot $。我们认为J1109+0754代表了Main \ textit {r} - 程序组件，这是由于与缩放 - 摩尔\ textit {r} -process component的良好一致。我们基于从\ texttt {inlustris-tng}仿真中提取的乳白色模拟模型，分析了该星的轨道历史。使用此模型，我们在年轻的宇宙时代对J1109+0754的相空间坐标进行了统计估计。总体而言，计算出的动作，衍生的化学和宇宙学模拟的结果表明，Lamost J1109+0754最有可能在低质量矮人星系中形成，并且属于银河系外部群体。
We report a comprehensive Chemo-dynamical analysis of LAMOST J1109+0754, a relatively bright (V = 12.8), extremely metal-poor ([Fe/H] = $-3.17$), and prograde ($J_ϕ$ and $V_ϕ$ $> 0$) star, with a strong \textit{r}-process enhancement ([Eu/Fe] = $+$0.94 $\pm$ 0.12, [Ba/Fe] = $-$0.52 $\pm$ 0.15). 31 chemical abundances (from Lithium to Thorium) were derived. We suggest a possible progenitor with stellar mass of 13.4-29.5 M$_\odot$. We argue that J1109+0754 is representative of the main \textit{r}-process component due to the well agreement with the scaled-solar \textit{r}-process component. We analyze the orbital history of this star in a {\it time-varying Galactic potential}, based on a Milky-Way analogue model extracted from \texttt{Illustris-TNG} simulations. Using this model, we carry out a statistical estimation of the phase-space coordinates of J1109+0754 at a young cosmic age. Collectively, the calculated motions, the derived chemistry, and the results from the cosmological simulations suggest that LAMOST J1109+0754 most likely formed in a low-mass dwarf galaxy, and belongs to the Galactic outer-halo population.
