DETECTING THE RISE AND FALL OF THE FIRST STARS BY THEIR IMPACT ON COSMIC REIONIZATION
DETECTING THE RISE AND FALL OF THE FIRST STARS BY THEIR IMPACT ON COSMIC REIONIZATION
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DOI：
10.1088/2041-8205/756/1/l16
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发表时间：
2012-06
期刊：
影响因子：
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通讯作者：
K. Ahn;I. Iliev;P. Shapiro;G. Mellema;J. Koda;Y. Mao
中科院分区：
文献类型：
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作者：
K. Ahn;I. Iliev;P. Shapiro;G. Mellema;J. Koda;Y. Mao
星系际介质在红移z ≥ 6之前被重电离，很可能是由早期星系逃逸的星光造成的。最早的恒星是在氢分子（H2）冷却最小星系内部的气体时形成的，这些星系是质量在105到108 M之间的迷你晕（MH）。虽然最早的恒星在红移z = 40之前就开始在这些MH内部形成，但迄今为止，它们的贡献在这种宇宙再电离的大规模模拟中被忽略了。在这里，我们报告的结果，从第一次再电离模拟，包括这些第一批恒星和辐射反馈，限制了他们的形成，在一个体积足够大，以遵循关键的空间变化，影响的过程及其可观测性。我们发现，虽然MH星停止远未完全电离宇宙，再电离开始早得多MH源比没有，并大大延长，这提高了星系际电子散射光学深度和大角度偏振波动的宇宙微波背景显着。这种增强应该很容易被普朗克探测到，尽管在目前的威尔金森微波各向异性探测器的不确定性范围内。如果再电离像其他观测所建议的那样，在zov 2007年结束，普朗克将因此看到第一批恒星的高红移信号，目前其他探测器无法检测到。
The intergalactic medium was reionized before redshift z ∼ 6, most likely by starlight which escaped from early galaxies. The very first stars formed when hydrogen molecules (H2) cooled gas inside the smallest galaxies, minihalos (MHs) of mass between 105 and 108 M☉. Although the very first stars began forming inside these MHs before redshift z ∼ 40, their contribution has, to date, been ignored in large-scale simulations of this cosmic reionization. Here we report results from the first reionization simulations to include these first stars and the radiative feedback that limited their formation, in a volume large enough to follow the crucial spatial variations that influenced the process and its observability. We show that, while MH stars stopped far short of fully ionizing the universe, reionization began much earlier with MH sources than without, and was greatly extended, which boosts the intergalactic electron-scattering optical depth and the large-angle polarization fluctuations of the cosmic microwave background significantly. This boost should be readily detectable by Planck, although within current Wilkinson Microwave Anisotropy Probe uncertainties. If reionization ended as late as zov ≲ 7, as suggested by other observations, Planck will thereby see the signature of the first stars at high redshift, currently undetectable by other probes.