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arXiv 2209.09345astro-ph.GA
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宇宙黎明时期星系风造成的星系际金属增丰程度

The extent of intergalactic metal enrichment from galactic winds during the Cosmic Dawn

Natsuko Yamaguchi, Steven R. Furlanetto, A. C. Trapp

AI总结:

本文构建超新星驱动星系风半解析模型,量化宇宙黎明时期正常星系与 Pop III 恒星对星系际金属增丰体积、吸收体丰度及 CMB 的影响。

摘要:

超新星反馈是宇宙黎明期间驱动星系演化的关键过程之一。这可能有助于调节星系内部的恒星形成,但也可以驱动影响大尺度星系际介质的星系风。在这里,我们提出了一个简单的超新星驱动星系风半解析模型,并探讨高红移(z > 6)宇宙中星系演化不同阶段对宇宙金属增丰的贡献。我们表明,根据 z~6-8 处观测到的星系光度函数校准的模型,在 z~6 处具有约1%的填充因子,在 z~12 处具有约0.1%的填充因子,不同的恒星形成处方带来约一个数量级的不确定性。尽管星系风填充的空间比例很小,但这些情景预测,z>5 时类星体光谱中金属线吸收体丰度的上限远高于目前观测到的数值。我们还考虑了 minihalos 中 Pop III 恒星形成驱动的星系风所造成的增丰。我们发现,这些星系风可以在 z>10 时主导总填充因子,甚至在 z~6 时与正常星系的星系风竞争,至少在总增丰体积方面是如此。但这些区域的整体金属丰度要低得多,因为每个区域都是由小规模的恒星形成爆发产生的。最后,我们表明,z>6 时这些超新星驱动星系风的 Compton 冷却对宇宙微波背景仅有很小的影响。

英文摘要:

One of the key processes driving galaxy evolution during the Cosmic Dawn is supernova feedback. This likely helps regulate star formation inside of galaxies, but it can also drive winds that influence the large-scale intergalactic medium. Here, we present a simple semi-analytic model of supernova-driven galactic winds and explore the contributions of different phases of galaxy evolution to cosmic metal enrichment in the high-redshift (z > 6) Universe. We show that models calibrated to the observed galaxy luminosity function at z~6-8 have filling factors ~1% at z~6 and ~0.1% at z~12, with different star formation prescriptions providing about an order of magnitude uncertainty. Despite the small fraction of space filled by winds, these scenarios predict an upper limit to the abundance of metal-line absorbers in quasar spectra at z>5 which is comfortably above that currently observed. We also consider enrichment through winds driven by Pop III star formation in minihalos. We find that these can dominate the total filling factor at z>10 and even compete with winds from normal galaxies at z~6, at least in terms of the total enriched volume. But these regions have much lower overall metallicities, because each one is generated by a small burst of star formation. Finally, we show that Compton cooling of these supernova-driven winds at z>6 has only a small effect on the cosmic microwave background.

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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