We study the effect of the gas accretion rate ($\dot M_{\rm accr}$) on the radial gas metallicity profile (RMP) of galaxies using the EAGLE cosmological hydrodynamic simulations, focusing on central galaxies of stellar mass $M_\star \gtrsim 10^9 \, {\rm M_\odot}$ at $z \le 1$. We find clear relations between $\dot M_{\rm accr}$ and the slope of the RMP (measured within an effective radius), where higher $\dot M_{\rm accr}$ are associated with more negative slopes. The slope of the RMPs depends more strongly on $\dot M_{\rm accr}$ than on stellar mass, star formation rate or gas fraction, suggesting $\dot M_{\rm accr}$ to be a more fundamental driver of the RMP slope of galaxies. We find that eliminating the dependence on stellar mass is essential for pinning down the properties that shape the slope of the RMP. Although $\dot M_{\rm accr}$ is the main property modulating the slope of the RMP, we find that it causes other correlations that are more easily testable observationally: at fixed stellar mass, galaxies with more negative RMP slopes tend to have higher gas fractions and SFRs, while galaxies with lower gas fractions and SFRs tend to have flatter metallicity profiles within an effective radius.

中文翻译：

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气体吸积对模拟星系径向气体金属丰度剖面的影响

我们使用 EAGLE 宇宙学流体动力学模拟研究气体吸积率 ($\dot M_{\rm accr}$) 对星系径向气体金属丰度分布 (RMP) 的影响，重点是恒星质量 $M_\star 的中央星系\gtrsim 10^9 \, {\rm M_\odot}$ 在 $z \le 1$。我们发现 $\dot M_{\rm accr}$ 与 RMP 的斜率（在有效半径内测量）之间存在明显的关系，其中更高的 $\dot M_{\rm accr}$ 与更多的负斜率相关。RMP 的斜率更依赖于 $\dot M_{\rm accr}$ 而不是恒星质量、恒星形成率或气体分数，这表明 $\dot M_{\rm accr}$ 是更基本的驱动力星系的 RMP 斜率。我们发现消除对恒星质量的依赖对于确定形成 RMP 斜率的特性至关重要。