GALACTIC OUTFLOWS AND PHOTOIONIZATION HEATING IN THE REIONIZATION EPOCH
GALACTIC OUTFLOWS AND PHOTOIONIZATION HEATING IN THE REIONIZATION EPOCH
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再电离时期的银河流出和光离子化加热
DOI：
10.1088/0004-637x/743/2/169
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
F. Ozel
中科院分区：
文献类型：
--
作者：
K. Finlator;R. Davé;F. Ozel
我们进行了一套新的宇宙学辐射流体动力学模拟，探讨了相对影响再电离时代的星星形成的银河系外流和光电离加热自洽增长的河外紫外线电离背景（EUVB）。我们比较的预测与观测的限制，从宇宙微波背景，紫外连续光度函数的星系，和Lyα森林。就其本身而言，EUVB在z = 6处抑制光度函数小于50%，即使它比观测到的强几个数量级。这使观测到的星系丰度超出了3-5倍，表明需要额外的反馈过程。我们证实，外流很容易抑制EUVB和光度函数到改进的协议与观测。星族I-II星星的形成，即使在存在来自光加热和外流的强烈反馈的情况下，也可以使宇宙的z = 6。由此产生的EUVB抑制星星形成的维里温度低于105 K的晕，但更大规模的晕有较弱的影响。尽管如此，由于EUVB的不均匀性，维里温度低于105 K的晕贡献了所有电离光子的约50%。总的来说，星星的形成率与晕质量Mh成比例，对于Mh = 108.2-1010.2 M的晕，Mh为1.3 - 1.4 h。这是一个比再电离模型中通常假设的更陡峭的依赖关系，在大尺度上提高了21厘米波动的预期功率谱。光度函数急剧上升到至少M1600 = −13，即使在处理流出和EUVB的模型中，也表明再电离是由尚未观测到的微弱星系（M1600 <$−15）驱动的。流出和EUVB以两种方式干扰彼此的反馈效应。外流削弱了EUVB，限制了Jeans对低质量晕的抑制;这导致了早期（z > 8）抑制的整体去放大。与此同时，它们会放大彼此对更大质量光环的影响，导致后期压制的整体放大。我们的模型不能同时解释星系、宇宙微波背景和星系际介质的观测结果。校正动态范围限制和调整我们的物理处理将减轻差异，但观察可能仍然需要额外的物理缩放，如质量依赖的电离逃逸分数。
We carry out a new suite of cosmological radiation hydrodynamic simulations that explores the relative impacts on reionization-epoch star formation of galactic outflows and photoionization heating from a self-consistently grown extragalactic ultraviolet ionizing background (EUVB). We compare the predictions with observational constraints from the cosmic microwave background, the ultraviolet continuum luminosity function of galaxies, and the Lyα forest. By itself, an EUVB suppresses the luminosity function by less than 50% at z = 6 even if it is orders of magnitude stronger than observed. This overproduces the observed galaxy abundance by a factor of 3–5, indicating the need for an additional feedback process. We confirm that outflows readily suppress both the EUVB and the luminosity function into improved agreement with observations. Population I–II star formation can reionize the universe by z = 6 even in the presence of strong feedback from photoheating and outflows. The resulting EUVB suppresses star formation in halos with virial temperatures below 105 K but has a weaker impact on more massive halos. Nonetheless, halos with virial temperatures below 105 K contribute up to ∼50% of all ionizing photons owing to the EUVB's inhomogeneity. Overall, star formation rate scales with halo mass Mh as M1.3–1.4h for halos with Mh = 108.2–1010.2 M☉. This is a steeper dependence than is often assumed in reionization models, boosting the expected power spectrum of 21 centimeter fluctuations on large scales. The luminosity function rises steeply to at least M1600 = −13 even in models that treat both outflows and an EUVB, indicating that reionization was driven by faint galaxies (M1600 ⩾ −15) that have not yet been observed. Outflows and an EUVB interfere with each other's feedback effects in two ways. Outflows weaken the EUVB, limiting Jeans suppression of low-mass halos; this leads to overall de-amplification of suppression at early times (z > 8). Meanwhile, they amplify each other's impact on more massive halos, leading to overall amplification of suppression at later times. Our models cannot simultaneously explain observations of galaxies, the cosmic microwave background, and the intergalactic medium. Correcting for dynamic range limitations and adjusting our physical treatments will alleviate discrepancies, but observations may still require additional physical scalings such as a mass-dependent ionizing escape fraction.
影响因子：
8.7
作者：
Komatsu, E.;Smith, K. M.;Wright, E. L.
通讯作者：
Wright, E. L.