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arXiv 2308.04476astro-ph.EPphysics.geo-ph
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地球吸积过程中金属/硅酸盐分异的改进模型

An improved model of metal/silicate differentiation during Earth's accretion

K. I. Dale, D. C. Rubie, M. Nakajima, S. Jacobson, G. Nathan, G. J. Golabek, S. Cambioni, A. Morbidelli

AI总结:

本文通过将巨型撞击平衡压力与全球岩浆海深度改为由SPH模拟确定,并假设星子物质先储存于上地幔,改进了地球吸积中金属/硅酸盐分异模型,使BSE成分及W、Mo丰度得到更好重现。

摘要:

我们改进了Rubie et al. (2015)提出的算法,以模拟地球在吸积过程中由铁/硅酸盐分异驱动的化学演化。在巨型撞击期间发生平衡的压力不再是一个自由参数,而是由Nakajima et al. (2021)的光滑粒子流体动力学(SPH)模拟确定。此外,现在假设撞击的星子太小,无法引起熔融和分异,因此它们的物质被储存在生长中行星的结晶上地幔中,直到巨型撞击之后形成一个流体静力学松弛的全球岩浆海,其深度也根据Nakajima et al. (2021)估算。经过这些修改,并非所有动力学模拟都能令人满意地重现全硅酸盐地球(BSE)的化学成分。因此,后者成为判断动力学模型是否成功的诊断标准。在成功的情况下,W和Mo的BSE丰度也可以被重现,而这些元素以前很难拟合(Jennings et al., 2021)。

英文摘要:

We improved the algorithm presented in Rubie et al. (2015) to model the chemical evolution of Earth driven by iron/silicate differentiation during the planet's accretion. The pressure at which the equilibration occurs during a giant impact is no longer a free parameter but is determined by the smooth particle hydrodynamic (SPH) simulations of Nakajima et al. (2021). Moreover, impacting planetesimals are now assumed to be too small to cause melting and differentiation and thus their materials are stored in the crystalline upper mantle of the growing planet until a hydrostatically relaxed global magma ocean forms in the aftermath of a giant impact, whose depth is also estimated from Nakajima et al. (2021). With these changes, not all dynamical simulations lead to a satisfactory reproduction of the chemical composition of the bulk silicate Earth (BSE). Thus, the latter becomes diagnostic of the success of dynamical models. In the successful cases also the BSE abundances of W and Mo can be reproduced, that were previously hard to fit (Jennings et al., 2021).

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。

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