Primordial magnetic fields in the post‐recombination era and early reionization
Primordial magnetic fields in the post‐recombination era and early reionization
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后复合时代和早期再电离的原始磁场
DOI：
10.1111/j.1365-2966.2004.08520.x/abs
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发表时间：
2004
影响因子：
4.8
通讯作者：
K. Subramanian
中科院分区：
文献类型：
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作者：
S. Sethi;K. Subramanian
我们探讨了原始磁场影响后复合宇宙的热和电离历史的方式。在复合之后，宇宙大部分变成中性，导致辐射粘性急剧下降。原始磁场然后可以通过双极扩散和足够小的尺度，通过产生衰减的磁流体动力学湍流将其能量耗散到星系际介质中。这些过程可以显著地改变复合后宇宙的热和电离历史。我们表明，磁场的耗散效应，即磁场红移到当前值B 0 = 3 × 10 - 9 G，在磁金斯尺度上平滑，可以引起汤姆逊散射光学深度τ？0.1，虽然不在解释最近威尔金森微波各向异性探测器（WMAP）偏振观测所需的红移范围内。我们还研究了原始领域的可能性，可以诱导形成的次星系结构的z？15.我们表明，早期结构的形成诱导纳高斯磁场是潜在的能够产生早期再电离暗示的WMAP数据。未来的宇宙微波背景辐射观测将有助于探测由原始磁场演化产生的修正电离历史并约束其强度。
We explore the ways in which primordial magnetic fields influence the thermal and ionization history of the post-recombination Universe. After recombination, the Universe becomes mostly neutral, resulting also in a sharp drop in the radiative viscosity. Primordial magnetic fields can then dissipate their energy into the intergalactic medium via ambipolar diffusion and, for small enough scales, by generating decaying magnetohydrodynamics turbulence. These processes can significantly modify the thermal and ionization history of the post-recombination Universe. We show that the dissipation effects of magnetic fields, which redshifts to a present value B 0 = 3 x 10 -9 G smoothed on the magnetic Jeans scale and below, can give rise to Thomson scattering optical depths τ? 0.1, although not in the range of redshifts needed to explain the recent Wilkinson Microwave Anisotropy Probe (WMAP) polarization observations. We also study the possibility that primordial fields could induce the formation of subgalactic structures for z? 15. We show that early structure formation induced by nanoGauss magnetic fields is potentially capable of producing the early reionization implied-by the WMAP data. Future cosmic microwave background observations will be very useful to probe the modified ionization histories produced by primordial magnetic field evolution and constrain their strength.