Constraining the 21 cm brightness temperature of the IGM at z = 6.6 around LAEs with the murchison widefield array
Constraining the 21 cm brightness temperature of the IGM at z = 6.6 around LAEs with the murchison widefield array
复制标题
DOI：
10.1093/mnras/stab2235
复制
发表时间：
2021-07
影响因子：
4.8
通讯作者：
C. Trott;C. Jordan;J. Line;C. Lynch;S. Yoshiura;B. McKinley;P. Dayal;B. Pindor;A. Hutter
中科院分区：
文献类型：
--
作者：
C. Trott;C. Jordan;J. Line;C. Lynch;S. Yoshiura;B. McKinley;P. Dayal;B. Pindor;A. Hutter
Lyα发射星系(LAE)在再电离纪元(EoR)结束时的位置预计与由红移21厘米超精细线追踪的电离氢区域相关。用探测到的和定位的LAE绘制区域周围的中性氢地图提供了一种途径，通过提供对气体空间分布的预期来限制EOR内宇宙的亮度温度，从而提供功率谱测量无法获得的先验信息。我们使用扩展阵列配置中Murchison Widefield阵列(MWA)12小时的观测测试集来限制58个LaE的中性氢特征，这些特征是在SilverRush调查中用Subaru Hypersuprime Cam探测到的，以z=6.58为中心。我们假设在电离结束时，可探测到的发射体位于电离HⅡ气泡的中心，并用一组不同的电离气泡半径来预测对应于剩余中性区域的红移中性氢信号。引入了预白化匹配滤波检测器来评估可检测性。我们展示了探测或限制亮度温度波动幅度和特征H II气泡大小的能力。利用我们有限的数据，对于半径为对数正态分布的气泡，我们将中性氢的亮度温度限制在ΔTb<；30mK(<；200mK)，置信度为95%(99%)，Rb=15±2小时−1 cmpc。
The locations of Ly α-emitting galaxies (LAEs) at the end of the Epoch of Reionization (EoR) are expected to correlate with regions of ionized hydrogen, traced by the redshifted 21 cm hyperfine line. Mapping the neutral hydrogen around regions with detected and localized LAEs offers an avenue to constrain the brightness temperature of the Universe within the EoR by providing an expectation for the spatial distribution of the gas, thereby providing prior information unavailable to power spectrum measurements. We use a test set of 12 h of observations from the Murchison Widefield Array (MWA) in extended array configuration, to constrain the neutral hydrogen signature of 58 LAEs, detected with the Subaru Hypersuprime Cam in the Silverrush survey, centred on z = 6.58. We assume that detectable emitters reside in the centre of ionized H ii bubbles during the end of reionization, and predict the redshifted neutral hydrogen signal corresponding to the remaining neutral regions using a set of different ionized bubble radii. A pre-whitening matched filter detector is introduced to assess detectability. We demonstrate the ability to detect, or place limits upon, the amplitude of brightness temperature fluctuations, and the characteristic H ii bubble size. With our limited data, we constrain the brightness temperature of neutral hydrogen to ΔTB <30 mK (<200 mK) at 95 per cent (99 per cent) confidence for lognormally distributed bubbles of radii, RB = 15 ± 2h−1 cMpc.