Chemical cartography with LAMOST and Gaia reveal azimuthal and spiral structure in the Galactic disc
Chemical cartography with LAMOST and Gaia reveal azimuthal and spiral structure in the Galactic disc
复制标题
LAMOST 和 Gaia 的化学制图揭示了银河盘中的方位角和螺旋结构
DOI：
10.1093/mnras/stad1244
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发表时间：
2023
影响因子：
4.8
通讯作者：
Hawkins, Keith
中科院分区：
文献类型：
--
作者：
Hawkins, Keith
我们银河系的化学制图或地图绘制有可能完全改变我们对银河系结构和形成的看法。在这项工作中，我们使用化学制图来探索LAMOST观测的OBAF型盘星的金属丰度分布和GaiaDR3的盘状巨星的补充样本。我们使用这些样本来限制整个银盘的径向和垂直金属丰度梯度。我们还探讨了在径向梯度之上的金属丰度分布是否存在可检测到的方位变化。对于来自LAMOST的OBAF型恒星样品，我们在圆盘平面上发现了Δ[Fe/H]/ΔR∼−0.078±0.001 dex的径向金属丰度梯度Kpc−1，在太阳附近发现了垂直的金属丰度梯度Δ[Fe/H]/ΔZ∼−0.15±0.01dex f kPc−1。径向梯度随着垂直高度的增加而变浅，垂直梯度随着银心半径的增加而变浅，这与其他研究结果一致。我们还在∼0.10dex水平的径向金属丰度梯度上发现了可检测到的空间相关方位变化。有趣的是，在一个数据集(GaiaDR3)中，方位变化似乎接近银河旋臂，但在另一个数据集(LAMOST)中却不是。这些结果表明，银河系金属丰度分布中存在方位结构，在某些情况下，它与旋臂共处。
Chemical Cartography, or mapping, of our Galaxy has the potential to fully transform our view of its structure and formation. In this work, we use chemical cartography to explore the metallicity distribution of OBAF-type disc stars from the LAMOST survey and a complementary sample of disc giant stars fromGaiaDR3. We use these samples to constrain the radial and vertical metallicity gradients across the Galactic disc. We also explore whether there are detectable azimuthal variations in the metallicity distribution on top of the radial gradient. For the OBAF-type star sample from LAMOST, we find a radial metallicity gradient of Δ[Fe/H]/ΔR∼−0.078 ± 0.001 dex kpc−1in the plane of the disc and a vertical metallicity gradient of Δ[Fe/H]/ΔZ∼−0.15 ± 0.01 dex kpc−1in the solar neighbourhood. The radial gradient becomes shallower with increasing vertical height, while the vertical gradient becomes shallower with increasing Galactocentric radius, consistent with other studies. We also find detectable spatially dependent azimuthal variations on top of the radial metallicity gradient at the level of ∼0.10 dex. Interestingly, the azimuthal variations appear be close to the Galactic spiral arms in one data set (GaiaDR3) but not the other (LAMOST). These results suggest that there is azimuthal structure in the Galactic metallicity distribution and that in some cases it is co-located with spiral arms.