论文标题
来自同质Ca-CN-CN-CH-NH光度法的球状簇的多个恒星种群。 vi。 M3（NGC 5272）不是典型的正常球状簇
Multiple Stellar Populations of Globular Clusters from Homogeneous Ca-CN-CH-NH Photometry. VI. M3 (NGC 5272) is not a Prototypical Normal Globular Cluster
论文作者
论文摘要
我们提出了众所周知的球状簇（GC）M3（NGC 5272）的CA-CN-CH-NH光度法。我们为两个M3群体和氮的丰度明显不同的M3种群展示了新的证据，在M3中的CN Weak和CN-Strong Red-Giant分支（RGB）之间存在明显的分裂。 CN-STRONG人群显示出C-N的抗相关性，这是CN周期的自然结果，而CN-Weak人群则显示没有或弱C-N反相关。此外，CN Weak人群表现出细长的空间分布，可能与其快速旋转有关。我们衍生的金属性在两个种群中都揭示了双峰金属性分布，其中$ \ langle $ [fe/h] $ \ rangle \ rangle \ your-$ 1.60和$ -1.45，这似乎负责离散的cn-weak和cn-wek和大的$ w^^{1g {1g {1g {1g} $ wek {$ w^{1g} $ wek; From this discovery, we propose that M3 consists of two GCs, namely the C1 (23\%, $\langle$[Fe/H]$\rangle\approx-1.60$) and C2 (77\%, $\langle$[Fe/H]$\rangle\approx-1.45$), each of which has its own C-N anticorrelation and structural and kinematical property,这是M3中独立系统的强烈指示。与银河系GC相比，C1和C2的CN Weak人群的分数都很高，但它们与Magellanic Clouds中的GC非常吻合。据信M3是两个GC的合并残留物，很可能是在矮星系环境中，并且后来又添加到我们的银河系中。这与最近关于M3的前态起源的建议一致。
We present Ca-CN-CH-NH photometry for the well-known globular cluster (GC) M3 (NGC 5272). We show new evidence for two M3 populations with distinctly different carbon and nitrogen abundances, seen in a sharp division between CN-weak and CN-strong red-giant branches (RGBs) in M3. The CN-strong population shows a C-N anticorrelation that is a natural consequence of the CN cycle, while the CN-weak population shows no or a weak C-N anticorrelation. Additionally, the CN-weak population exhibits an elongated spatial distribution that is likely linked to its fast rotation. Our derived metallicity reveals bimodal metallicity distributions in both populations, with $\langle$[Fe/H]$\rangle\approx-$1.60 and $-$1.45, which appear to be responsible for the discrete double RGB bumps in the CN-weak and the large $W^{1G}_{F275W-F814W}$ range. From this discovery, we propose that M3 consists of two GCs, namely the C1 (23\%, $\langle$[Fe/H]$\rangle\approx-1.60$) and C2 (77\%, $\langle$[Fe/H]$\rangle\approx-1.45$), each of which has its own C-N anticorrelation and structural and kinematical property, which is a strong indication of independent systems in M3. The fractions of the CN-weak population for both the C1 and C2 are high compared to Galactic GCs but they are in good agreement with GCs in Magellanic Clouds. It is believed that M3 is a merger remnant of the two GCs, most likely in a dwarf galaxy environment, and accreted to our Galaxy later in time. This is consistent with recent proposals of an ex-situ origin of M3.
