论文标题

恒星风的机械反馈,并在高红移时应用到星系形成

Mechanical feedback from stellar winds with an application to galaxy formation at high redshift

论文作者

Fichtner, Yvonne A., Grassitelli, Luca, Romano-Díaz, Emilio, Porciani, Cristiano

论文摘要

我们计算不同的恒星进化轨道集,以量化大量主要序列和中风后风产生的能量,质量和金属。我们的目的是研究二进制系统的影响以及最初旋转速度对恒星风反馈的金属性依赖性分布。与常用的非旋转单星情景相比,我们发现重大变化。在低金属性下,最大的差异很明显,其中机械能量预算大大增加。 So as to establish the maximal (i.e. obtained by neglecting dissipation in the near circumstellar environment) influence of winds on the early stages of galaxy formation, we use our new feedback estimates to simulate the formation and evolution of a sub-$L_*$ galaxy at redshift 3 (hosted by a dark-matter halo with a mass of $1.8\times 10^{11}$ M$_\odot$)并将结果与​​仅考虑超新星(SN)反馈的模拟进行比较。考虑到风的连续能量注入会减少恒星质量,金属含量以及恒星形成速率的爆发以及流出的气体质量。但是,我们的数值实验表明,与非旋转的单星情景相比,旋转和二进制恒星风中的机械反馈对最相关的银河系特性的影响有限。最终,我们查看了风中夹带的金属与SNE弹出的金属之间的相对丰度,并发现它在模拟的银河系及其周围光环中几乎保持恒定。

We compute different sets of stellar evolutionary tracks in order to quantify the energy, mass, and metals yielded by massive main-sequence and post-main-sequence winds. Our aim is to investigate the impact of binary systems and of a metallicity-dependent distribution of initial rotational velocities on the feedback by stellar winds. We find significant changes compared to the commonly used non-rotating, single-star scenario. The largest differences are noticeable at low metallicity, where the mechanical-energy budget is substantially increased. So as to establish the maximal (i.e. obtained by neglecting dissipation in the near circumstellar environment) influence of winds on the early stages of galaxy formation, we use our new feedback estimates to simulate the formation and evolution of a sub-$L_*$ galaxy at redshift 3 (hosted by a dark-matter halo with a mass of $1.8\times 10^{11}$ M$_\odot$) and compare the outcome with simulations in which only supernova (SN) feedback is considered. Accounting for the continuous energy injection by winds reduces the total stellar mass, the metal content, and the burstiness of the star-formation rate as well as of the outflowing gas mass. However, our numerical experiment suggests that the enhanced mechanical feedback from the winds of rotating and binary stars has a limited impact on the most relevant galactic properties compared to the non-rotating single-star scenario. Eventually, we look at the relative abundance between the metals entrained in winds and those ejected by SNe and find that it stays nearly constant within the simulated galaxy and its surrounding halo.

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