Title: The impact of wind mass loss on nucleosynthesis and yields of very massive stars at low metallicity Show Chinese title

Title: 低金属丰度下风质量损失对极高质量恒星的核合成及其产率的影响

Abstract: The chemical feedback from stellar winds in low metallicity (Z) environments is key for understanding the evolution of globular clusters and the early Universe. With disproportionate mass lost from the most massive stars (M > 100Msun), and an excess of such stars expected at the lowest metallicities, their contribution to the enrichment of the early pristine clusters could be significant. In this work, we examine the effect of mass loss at low metallicity on the nucleosynthesis and wind yields of (very) massive stars. We calculate stellar models with initial masses ranging from 30 to 500Msun during core Hydrogen and Helium burning phases, at four metallicities ranging from 20% Zsun down to 1% Zsun. The ejected masses and net yields are provided for each grid of models. While mass-loss rates decrease with Z, we find that not only are wind yields significant, but the nucleosynthesis is also altered due to the change in central temperatures and therefore also plays a role. We find that 80-300Msun models can produce large quantities of Na-rich and O-poor material, relevant for the observed Na-O anti-correlation in globular clusters. Show Chinese abstract

Abstract: 低金属丰度（Z）环境下来自恒星风的化学反馈对于理解球状星团和早期宇宙的演化至关重要。由于最 massive 的恒星（M > 100Msun）质量损失不成比例，并且预计在最低金属丰度下会有过多此类恒星，它们对早期原始星团富集的贡献可能很大。 在这项工作中，我们研究了低金属丰度下质量损失对（非常）大质量恒星核合成和风产额的影响。我们计算了核心氢和氦燃烧阶段初始质量范围从 30 到 500Msun 的恒星模型，在四种金属丰度范围内，从 20\% Zsun 到 1\% Zsun。每个模型网格提供了喷发质量和净产额。尽管质量损失速率随 Z 减小，但我们发现不仅风产额显著，而且由于中心温度的变化，核合成也受到影响，因此也起作用。我们发现 80-300Msun 模型可以产生大量富含 Na 和贫氧的物质，与球状星团中观测到的 Na-O 反相关有关。