arXiv 2102.120032021-02-24astro-ph.GA

高α和低α盘的普适性质：小内禀丰度散射和迁移星

Universal properties of the high- and low-α disk: small intrinsic abundance scatter and migrating stars

Yuxi, Lu, Melissa Ness, Tobias Buck, Joel Zinn

DOI：: 10.1093/mnras/stac610

摘要：

详细的恒星年龄-化学丰度关系测量了与时间相关的化学演化，这些趋势为核合成过程以及恒星形成气体的丰度提供了强有力的经验约束。最近，由于盖亚、APOGEE和开普勒等观测，描述银河系中恒星随时间变化的化学丰度已经成为可能。对低$α$盘的研究表明，个别元素具有独特的年龄-丰度趋势，并且围绕这些关系的固有色散很小。在这项研究中，我们检查和比较的年龄分布的恒星在高和低的$α$磁盘和量化的内在分散的16个元素周围的年龄-丰度关系在[Fe/H] = 0使用APOGEE DR 16。我们发现，高$α$磁盘具有较浅的年龄-丰度关系相比，低$α$磁盘，但类似的中值固有分散度为~ 0.04 dex，这表明通用的元素生产机制的高和低$α$磁盘，尽管在形成历史上的差异。我们可视化的时间和空间分布的盘星在小的化学细胞，揭示了倒置和由内而外形成的签名。此外，金属丰度偏斜和[Fe/H]-年龄关系-跨半径表明不同的初始金属丰度梯度和径向迁移的证据。我们的研究伴随着64，317颗星的年龄目录，这些星是使用大炮在所有年龄（APO-CAN星）中的~ 1.9 Gyr不确定度导出的，以及22，031颗星的红团目录，污染率为2.7%。

英文摘要：

The detailed age-chemical abundance relations of stars measures time-dependent chemical evolution.These trends offer strong empirical constraints on nucleosynthetic processes, as well as the homogeneityof star-forming gas. Characterizing chemical abundances of stars across the Milky Way over time has been made possible very recently, thanks to surveys like Gaia, APOGEE and Kepler. Studies of the low-$α$ disk have shown that individual elements have unique age-abundance trends and the intrinsic dispersion around these relations is small. In this study, we examine and compare the age distribution of stars across both the high and low-$α$ disk and quantify the intrinsic dispersion of 16 elements around their age-abundance relations at [Fe/H] = 0 using APOGEE DR16. We find the high-$α$ disk has shallower age-abundance relations compared to the low-$α$ disk, but similar median intrinsic dispersions of ~ 0.04 dex, suggesting universal element production mechanisms for the high and low-$α$ disks, despite differences in formation history. We visualize the temporal and spatial distribution of disk stars in small chemical cells, revealing signatures of upside-down and inside-out formation. Further,the metallicity skew and the [Fe/H]-age relations - across radius indicates different initial metallicity gradients and evidence for radial migration. Our study is accompanied by an age catalogue for 64,317 stars in APOGEE derived usingThe Cannon with ~ 1.9 Gyr uncertainty across all ages (APO-CAN stars) as well as a red clump catalogue of 22,031 stars with a contamination rate of 2.7%.

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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