We conducted a search for technosignatures in April of 2018 and 2019 with the L-band receiver (1.15-1.73 GHz) of the 100 m diameter Green Bank Telescope. These observations focused on regions surrounding 31 Sun-like stars near the plane of the Galaxy. We present the results of our search for narrowband signals in this data set as well as improvements to our data processing pipeline. Specifically, we applied an improved candidate signal detection procedure that relies on the topographic prominence of the signal power, which nearly doubles the signal detection count of some previously analyzed data sets. We also improved the direction-of-origin filters that remove most radio frequency interference (RFI) to ensure that they uniquely link signals observed in separate scans. We performed a preliminary signal injection and recovery analysis to test the performance of our pipeline. We found that our pipeline recovers 93% of the injected signals over the usable frequency range of the receiver and 98% if we exclude regions with dense RFI. In this analysis, 99.73% of the recovered signals were correctly classified as technosignature candidates. Our improved data processing pipeline classified over 99.84% of the ~26 million signals detected in our data as RFI. Of the remaining candidates, 4539 were detected outside of known RFI frequency regions. The remaining candidates were visually inspected and verified to be of anthropogenic nature. Our search compares favorably to other recent searches in terms of end-to-end sensitivity, frequency drift rate coverage, and signal detection count per unit bandwidth per unit integration time.
The Breakthrough Listen Search for Intelligent Life: A 3.95-8.00 GHz Search for Radio Technosignatures in the Restricted Earth Transit Zone
我们报告了在受限的地球过境区内搜索20颗恒星的人造窄带信号，这是为期十年的突破性聆听（BL）搜索外星智慧的一部分。限制地球凌日区是一个天空区域，从这个区域观察者可以看到地球以小于0.5的碰撞参量凌日。这片天空在几何学上是独一无二的，为外星智慧生物发现太阳系提供了一条潜在的途径。目标就在附近（7-143 pc），搜索覆盖了3.95-8.00 GHz的电磁频率范围。我们使用了罗伯特C。伯德绿岸望远镜执行这些观测与标准的BL数据记录器。我们在这些数据中搜索多普勒漂移率为$\pm 20$ Hz s $^{-1}$的人工窄带（$\sim$ Hz）信号。我们在目标HIP 109656上发现了一组潜在的候选信号，然后发现其与人为射频干扰的已知特性一致。在我们的观测中，我们没有发现来自外星智慧生物的无线电技术特征的证据。观测活动实现了最小可探测通量，这将允许探测发射，其强度分别为最近和最远恒星的阿雷西博雷达发射机信号能力的$10^{-3}$至$0.88$倍。我们的结论是，至少$8\%$的系统在150 pc内的限制地球过境区不具备在本次调查中搜索的发射机类型。据我们所知，这是第一次有针对性的搜索外星智慧的限制地球过境区。本文中使用的所有数据都可通过Breakthrough Listen Public Data Archive（http：//seti.berkeley.edu/bldr2）公开获取。
A Search for Radio Technosignatures from Interstellar Object 3I/ATLAS with the Allen Telescope Array
SETI Institute（SETI研究所）；Berkeley SETI Research Center（伯克利SETI研究中心）；Furman University（福尔曼大学）；Breakthrough Listen, University of California, Berkeley（加州大学伯克利分校突破聆听计划）；University of Oxford（牛津大学）；Department of Astronomy and the DiRAC Institute, University of Washington（华盛顿大学天文学系及DiRAC研究所）；University of Central Arkansas（阿肯色中央大学）
