Title: Population-Dependent r-process Scatter in the Globular Cluster M15 Show Chinese title

Title: 依赖于星团的r过程散射在球状星团M15中

Abstract: Multiple populations, defined by correlations between light element abundances, are an almost ubiquitous property of globular clusters. On the other hand, dispersions among the heavy elements are limited to a few rare clusters. In this letter, we present Mg, Y, Ba, La, and Eu measurements for 89 stars in M15 with errors < 0.4 dex from Keck/DEIMOS medium-resolution spectra. We find higher Ba, La, and Eu dispersions in the first generation of stars than in the second generation at a significance of $\ge$2 $\sigma$. This is evidence for inhomogeneous mixing of gas during the formation of the first generation of stars, which subsequently became well-mixed prior to the formation of the second generation of stars. If the r-process event that caused the abundance dispersions was born with the first population of stars, it must be an r-process site with a short delay time. Show Chinese abstract

Abstract: 多重种群是由轻元素丰度之间的相关性定义的，这是球状星团几乎普遍具有的特性。 另一方面，重元素的弥散仅限于少数罕见的星团。 在本文中，我们展示了来自凯克/DEIMOS中分辨率光谱的89颗M15恒星的Mg、Y、Ba、La和Eu测量结果，误差小于0.4 dex。 我们在第一代恒星中发现比第二代恒星更高的Ba、La和Eu弥散，显著性为$\ge$2 $\sigma$。 这表明在第一代恒星形成期间气体存在不均匀混合，随后在第二代恒星形成之前变得均匀混合。 如果导致丰度弥散的r过程事件伴随着第一代恒星产生，那么它必须是一个具有短延迟时间的r过程场所。