Title: HI absorption from the epoch of reionization and primordial magnetic fields Show Chinese title

Title: 再电离时代的HI吸收和原初磁场

Abstract: We study the impact of primordial magnetic fields on the HI absorption from the Epoch of Reionization. The presence of these fields result in two distinct effects: (a) the heating of the haloes from the decay of magnetic fields owing to ambipolar diffusion, and (b) an increase in the number of haloes owing to additional matter fluctuations induced by magnetic fields. We analyse both these effects and show that the latter is potentially observable because the number of haloes along of line of sight can increase by many orders of magnitude. While this effect is not strongly dependent on the magnetic field strength in the range $0.3\hbox{--}0.6$ nG, it is extremely sensitive to the magnetic field power spectral index for the near scale-free models. Therefore the detection of such absorption features could be a sensitive probe of the primordial magnetic field and its power spectrum. We discuss the detectability of these features with the ongoing and future radio interferometers. In particular, we show that LOFAR might be able to detect these absorption features at $z \simeq 10$ in less than 10 hrs of integration if the flux of the background source is 400 mJy. Show Chinese abstract

Abstract: 我们研究了原初磁场对再电离时代的HI吸收的影响。 这些磁场的存在导致了两种不同的效应：(a)由于磁扩散造成的磁场衰减而引起的晕团加热，以及(b)由于磁场引起的额外物质波动而导致的晕团数量增加。 我们分析了这两种效应，并表明后者可能是可观察到的，因为视线方向上的晕团数量可以增加多个数量级。 虽然这种效应在磁场强度范围为$0.3\hbox{--}0.6$纳高斯时并不强烈依赖于磁场强度，但对于接近尺度无关模型的磁场功率谱指数却极其敏感。 因此，检测到此类吸收特征可能是探测原初磁场及其功率谱的一种灵敏探针。 我们讨论了这些特征通过当前和未来的射电干涉仪的可探测性。 特别是，我们展示了如果背景源的通量为400毫焦耳/平方米，LOFAR可能在不到10小时的积分时间内在$z \simeq 10$检测到这些吸收特征。