Hydrogen reionization in the Illustris universe
Hydrogen reionization in the Illustris universe
复制标题
Illustris 宇宙中的氢再电离
DOI：
10.1093/mnras/stv1893
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发表时间：
2015
影响因子：
4.8
通讯作者：
Bauer A
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作者：
Bauer A
星系形成的流体动力学模拟，如Illustris模拟已经发展到一个状态，他们近似地再现了从高红移到低红移的恒星质量函数。这在原则上允许自洽模型的再电离，利用扩散气体分布的准确表示连同这些模拟提供的星系的现实增长，在一个有代表性的宇宙体积。在这项工作中，我们应用和比较两个辐射传输算法实现的GPU加速代码的106.5-Mpc宽体积的Illustris在后处理，以调查再电离过渡预测该模型。我们发现，第一代星系形成的插图是刚刚能够reflecting宇宙的redshiftz 107，提供相当乐观的假设逃逸分数和分辨率的限制。我们最乐观的模型发现光学深度为τ = 0.065，这与最近普朗克2015年的测定结果非常一致。此外，我们表明，矩为基础的方法与M1封闭的辐射传输与我们的角分辨辐射传输方案给出了广泛一致的结果。在我们喜欢的基准模型中，20%的氢在红移= 9.20时被再电离，而在红移= 6.92时，这一比例迅速上升到80%。直到z = 6.24，99%的氢才被电离。平均而言，再电离在我们的模型中进行“由内而外”，再电离气泡的尺寸分布逐渐具有越来越大的尺寸区域，而小气泡的丰度保持相当恒定。
Hydrodynamical simulations of galaxy formation such as the Illustris simulations have progressed to a state where they approximately reproduce the observed stellar mass function from high to low redshift. This in principle allows self-consistent models of reionization that exploit the accurate representation of the diffuse gas distribution together with the realistic growth of galaxies provided by these simulations, within a representative cosmological volume. In this work, we apply and compare two radiative transfer algorithms implemented in a GPU-accelerated code to the 106.5-Mpc-wide volume of Illustris in post-processing in order to investigate the reionization transition predicted by this model. We find that the first generation of galaxies formed by Illustris is just about able to reionize the universe by redshiftz∼ 7, provided quite optimistic assumptions about the escape fraction and the resolution limitations are made. Our most optimistic model finds an optical depth of τ ≃ 0.065, which is in very good agreement with recentPlanck2015 determinations. Furthermore, we show that moment-based approaches for radiative transfer with the M1 closure give broadly consistent results with our angular-resolved radiative transfer scheme. In our favoured fiducial model, 20 per cent of the hydrogen is reionized by redshiftz= 9.20, and this rapidly climbs to 80 per cent by redshiftz= 6.92. It then takes untilz= 6.24 before 99 per cent of the hydrogen is ionized. On average, reionization proceeds ‘inside-out’ in our models, with a size distribution of reionized bubbles that progressively features regions of ever larger size while the abundance of small bubbles stays fairly constant.
“与组方案相关的角色产品和平衡集”（预印本）。
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