IAA, Academia Sinica, PO Box 23-141, Taipei 10617, Taiwan.
Nature. 2010 Jul 22;466(7305):463-5. doi: 10.1038/nature09187.
Observations of 21-cm radio emission by neutral hydrogen at redshifts z approximately 0.5 to approximately 2.5 are expected to provide a sensitive probe of cosmic dark energy. This is particularly true around the onset of acceleration at z approximately 1, where traditional optical cosmology becomes very difficult because of the infrared opacity of the atmosphere. Hitherto, 21-cm emission has been detected only to z = 0.24. More distant galaxies generally are too faint for individual detections but it is possible to measure the aggregate emission from many unresolved galaxies in the 'cosmic web'. Here we report a three-dimensional 21-cm intensity field at z = 0.53 to 1.12. We then co-add neutral-hydrogen (H i) emission from the volumes surrounding about 10,000 galaxies (from the DEEP2 optical galaxy redshift survey). We detect the aggregate 21-cm glow at a significance of approximately 4sigma.
观测红移约 0.5 到约 2.5 的中性氢的 21 厘米射电辐射，有望成为探测宇宙暗能量的灵敏探针。在 z 约为 1 时加速开始时尤其如此，由于大气的红外不透明度，传统的光学宇宙学变得非常困难。迄今为止，仅在 z = 0.24 处探测到了 21 厘米的发射。更远的星系通常太暗，无法进行单个探测，但可以测量许多未解析星系在“宇宙网”中的总发射。在这里，我们报告了 z = 0.53 到 1.12 的三维 21 厘米强度场。然后，我们对大约 10000 个星系（来自 DEEP2 光学星系红移调查）周围的体积中的中性氢（H i）发射进行了共加。我们以约 4sigma 的显著水平检测到了总 21 厘米辉光。
