标题： 一个用于暗 Ages 21-cm 宇宙学的月球远端低频阵列 显示英文标题

标题： A Lunar Farside Low Radio Frequency Array for Dark Ages 21-cm Cosmology

摘要： 月球远端表面上的一组低频偶极子天线将探测宇宙早期一个独特且尚未被探索的时代，称为“黑暗时代”。 它始于复合时期，当时中性氢原子形成，并首次由宇宙微波背景揭示。 这一时代没有恒星和天体物理学，因此非常适合研究高能粒子过程，包括暗物质、早期暗能量、中微子和宇宙弦。 一项由NASA资助的研究调查了仪器的设计以及从着陆器部署128对天线偶极子的策略，这些天线分布在月球表面的一个10公里 x 10公里区域内。 天线节点通过缆绳连接到着陆器，用于中央数据处理、电源供应以及与中继卫星的数据传输。 该阵列名为FARSIDE，将有能力以1400个通道成像整个天空，频率范围从100 kHz到40 MHz，向下延伸两个数量级，低于地面射电天文学可访问的频段。 月球远端同时提供了隔离地球射频干扰、地球极光千米辐射以及太阳风等离子噪声的能力。 因此，它是内太阳系中唯一可以从亚兆赫兹频率进行天空噪声限制观测的位置。 通过轨道信标进行精确校准和前沿特征描述，远端阵列将在红移z~35-200处测量黑暗时代的全球21厘米信号。 它还将通过高动态范围仔细测量前景，为更大规模的21厘米功率谱仪铺平道路。 显示英文摘要

摘要： An array of low-frequency dipole antennas on the lunar farside surface will probe a unique, unexplored epoch in the early Universe called the Dark Ages. It begins at Recombination when neutral hydrogen atoms formed, first revealed by the cosmic microwave background. This epoch is free of stars and astrophysics, so it is ideal to investigate high energy particle processes including dark matter, early Dark Energy, neutrinos, and cosmic strings. A NASA-funded study investigated the design of the instrument and the deployment strategy from a lander of 128 pairs of antenna dipoles across a 10 kmx10 km area on the lunar surface. The antenna nodes are tethered to the lander for central data processing, power, and data transmission to a relay satellite. The array, named FARSIDE, would provide the capability to image the entire sky in 1400 channels spanning frequencies from 100 kHz to 40 MHz, extending down two orders of magnitude below bands accessible to ground-based radio astronomy. The lunar farside can simultaneously provide isolation from terrestrial radio frequency interference, the Earth's auroral kilometric radiation, and plasma noise from the solar wind. It is thus the only location within the inner solar system from which sky noise limited observations can be carried out at sub-MHz frequencies. Through precision calibration via an orbiting beacon and exquisite foreground characterization, the farside array would measure the Dark Ages global 21-cm signal at redshifts z~35-200. It will also be a pathfinder for a larger 21-cm power spectrum instrument by carefully measuring the foreground with high dynamic range.