arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2501.11209astro-ph.GA
收藏

超新星反馈对宇宙学模拟中金属丰度梯度演化的影响

The impact of supernova feedback on metallicity-gradient evolution in cosmological simulations

Dyna Ibrahim, Chiaki Kobayashi

备注：
22 pages, 25 figures. Accepted for publication in MNRAS
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

AI总结：

本文利用宇宙学化学动力学模拟，比较热能、随机和机械三种超新星反馈模型，研究星系恒星与星际介质径向金属丰度梯度的演化，发现机械反馈在 $z=0$ 与观测最吻合，并揭示了梯度随质量与红移的演化规律及内向外生长模式。

摘要：

追踪星系的宇宙路径需要了解其化学富集与并合历史。最重要的约束之一是星系的内部结构，特别是作为河外考古学化石的元素内部分布。利用我们的宇宙学化学动力学模拟（包含所有相关物理过程和最新核合成产率），我们研究了每个星系内恒星种群和星际介质径向金属丰度梯度的演化。本工作通过比较三种反馈模型（以热能、随机和机械形式抛射能量），探讨了超新星反馈对金属丰度梯度的作用。在 $z=0$ 时，机械反馈模型产生的恒星和气体梯度—质量关系均与观测高度一致；中等质量（$M_*\sim10^{10}M_\odot$）星系梯度最陡，而在大质量星系中变平，可能由主并合导致。对每个模型，我们预测至 $z=4$ 的相似梯度—质量关系，并发现机械反馈模型对低质量星系（$M_*<10^{10}M_\odot$）给出更平缓的恒星与气体梯度，可能源于恒星反馈对恒星形成的抑制和金属抛射。在所有反馈模型中，多数星系至 $z=5$ 具有负的气相金属丰度梯度，表明内向外生长，这与其他宇宙学模拟一致，但与 $z\sim1$--2.5 的近期观测不符。我们发现至 $z=4$ 梯度存在温和的红移演化，而在 $z=5$ 似乎出现演化转变，气相与恒星金属丰度梯度变陡。这些需用更高分辨率模拟和观测进一步研究。

英文摘要：

Tracing the cosmic path of galaxies requires an understanding of their chemical enrichment and merging histories. One of the most important constraints is the internal structure of galaxies, notably the internal distribution of elements acting as fossils in extra-galactic archaeology. Using our cosmological chemodynamical simulations, which include all relevant physical processes and the latest nucleosynthesis yields, we investigate the evolution of radial metallicity gradients of stellar populations and the interstellar medium within each galaxy. This work explores the role of supernova feedback on the metallicity gradients by comparing three feedback models, ejecting energy in thermal, stochastic and mechanical forms. At $z=0$, the mechanical feedback model produces the gradient--mass relations of stars and gas both in excellent agreement with observations; gradients are the steepest at intermediate-mass ($M_*\sim10^{10}M_\odot$) and become flatter in massive galaxies probably by major mergers. For each model, we predict similar gradient--mass relations up to $z=4$ and find that the mechanical feedback model gives flatter gradients of both stars and gas for lower-mass galaxies ($M_*<10^{10}M_\odot$) possibly due to the suppression of star formation and metal ejection by stellar feedback. With all feedback models, most galaxies have negative gas-phase metallicity gradients up to $z=5$, suggesting an inside-out growth, which is consistent with other cosmological simulations but not with recent observations at $z\sim1$--2.5. We find a mild redshift evolution of gradients up to $z=4$, while there seems to be an evolutionary transition at $z=5$ where the metallicity gradients become steep for gas and stars. These should be investigated with higher-resolution simulations and observations.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑