TAROGE-M: radio antenna array on antarctic high mountain for detecting near-horizontal ultra-high energy air showers
TAROGE-M: radio antenna array on antarctic high mountain for detecting near-horizontal ultra-high energy air showers
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DOI：
10.1088/1475-7516/2022/11/022
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发表时间：
2022-07
影响因子：
6.4
通讯作者：
Shih-Hao Wang;J. Nam;Pisin Chen;Yaocheng Chen;T. Choi;Young-bae Ham;Shih-Ying Hsu;Jian-Jung Huang;M. Huang;G. Jee;Jongil Jung;Jieun Kim;C. Kuo;H. Kwon;Changsup Lee;C. Leung;Tsung-Che Liu;Y. Shiao;B. Shin;Minzu Wang;Yu-Hsin Wang;A. Anker;S. Barwick;D. Besson;S. Bouma;M. Cataldo;G. Gaswint;C. Glaser;S. Hallmann;J. Hanson;J. Henrichs;S. Kleinfelder;R. Lahmann;Z. Meyers;A. Nelles;A. Novikov;M. P. Paul;L. Pyras;C. Persichilli;I. Plaisier;R. Rice-Smith;M. Seikh;J. Tatar;C. Welling;Leshan Zhao
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文献类型：
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作者：
Shih-Hao Wang;J. Nam;Pisin Chen;Yaocheng Chen;T. Choi;Young-bae Ham;Shih-Ying Hsu;Jian-Jung Huang;M. Huang;G. Jee;Jongil Jung;Jieun Kim;C. Kuo;H. Kwon;Changsup Lee;C. Leung;Tsung-Che Liu;Y. Shiao;B. Shin;Minzu Wang;Yu-Hsin Wang;A. Anker;S. Barwick;D. Besson;S. Bouma;M. Cataldo;G. Gaswint;C. Glaser;S. Hallmann;J. Hanson;J. Henrichs;S. Kleinfelder;R. Lahmann;Z. Meyers;A. Nelles;A. Novikov;M. P. Paul;L. Pyras;C. Persichilli;I. Plaisier;R. Rice-Smith;M. Seikh;J. Tatar;C. Welling;Leshan Zhao
TAROGE-M射电天文台是位于海拔2700 m的Mt.顶部的自触发天线阵列。南极洲的墨尔本，旨在探测由超过1017 eV的超高能（UHE）粒子引起的大范围空气簇射的脉冲地磁发射，包括宇宙射线，掠地τ中微子，特别是来自地平线附近和地平线以下的“ANITA异常事件”（AAE）。ANITA实验发现的六个AAE具有类似于τ中微子的信号特征，但这一假设与标准模型预测的相互作用长度或其他实验设定的通量限制存在矛盾。它们的起源仍然不确定，需要更多的实验投入来澄清。TAROGE-M的探测概念利用了高海拔和朝向地平线的天气视图作为有效的信号收集器，以及南极洲的无线电安静和强且接近垂直的地磁场，增强了相对无线电信号强度。该方法具有能量阈值低、占空比高、易于扩展等优点，可快速扩大统计量。在这里，我们报告了2020年1月部署的第一个TAROGE-M站的实验结果，相当于大约一个月的生存时间。该台站由六个接收天线组成，工作频率为180-450兆赫，可以重建脉冲事件的源方向，角分辨率为10.3 °，用无人机携带的脉冲发生器系统进行现场校准。为了证明TAROGE-M探测UHE空气簇射的能力，在25.3天的数据中搜索宇宙射线信号，并进行了探测模拟，结果确定了7个候选者。探测到的事件的平均重建能量为0.95-0.31 ± 0.46 EeV，天顶角范围为25°至82°，两种分布与模拟一致，表明能量阈值约为0.3 EeV。该能量下的宇宙线通量估计值为1.2-0.9 + 0.7 × 10-16 eV-1 km-2 yr-1 sr-1，与其他实验结果一致。TAROGE-M对AAE的灵敏度近似于τ中微子暴露与模拟，这表明与ANITA在大约1 EeV的能量下具有几个站年的操作相当的灵敏度。这些第一批结果验证了在极地和高海拔环境中的台站设计和性能，并有望在不久的将来扩展后进一步发现τ中微子和AAE。
The TAROGE-M radio observatory is a self-triggered antenna array on top of the ∼2700 m high Mt. Melbourne in Antarctica, designed to detect impulsive geomagnetic emission from extensive air showers induced by ultra-high energy (UHE) particles beyond 1017 eV, including cosmic rays, Earth-skimming tau neutrinos, and particularly, the “ANITA anomalous events” (AAE) from near and below the horizon. The six AAE discovered by the ANITA experiment have signal features similar to tau neutrinos but that hypothesis is in tension either with the interaction length predicted by Standard Model or with the flux limits set by other experiments. Their origin remains uncertain, requiring more experimental inputs for clarification. The detection concept of TAROGE-M takes advantage of a high altitude with synoptic view toward the horizon as an efficient signal collector, and the radio quietness as well as strong and near vertical geomagnetic field in Antarctica, enhancing the relative radio signal strength. This approach has a low energy threshold, high duty cycle, and is easy to extend for quickly enlarging statistics. Here we report experimental results from the first TAROGE-M station deployed in January 2020, corresponding to approximately one month of livetime. The station consists of six receiving antennas operating at 180–450 MHz, and can reconstruct source directions of impulsive events with an angular resolution of ∼0.3°, calibrated in situ with a drone-borne pulser system. To demonstrate TAROGE-M's ability to detect UHE air showers, a search for cosmic ray signals in 25.3-days of data together with the detection simulation were conducted, resulting in seven identified candidates. The detected events have a mean reconstructed energy of 0.95-0.31 +0.46 EeV and zenith angles ranging from 25° to 82°, with both distributions agreeing with the simulations, indicating an energy threshold at about 0.3 EeV. The estimated cosmic ray flux at that energy is 1.2-0.9 +0.7 × 10-16 eV-1 km-2 yr-1 sr-1, also consistent with results of other experiments. The TAROGE-M sensitivity to AAEs is approximated by the tau neutrino exposure with simulations, which suggests comparable sensitivity as ANITA's at around 1 EeV energy with a few station-years of operation. These first results verified the station design and performance in a polar and high-altitude environment, and are promising for further discovery of tau neutrinos and AAEs after an extension in the near future.