发表机构
University of New Mexico; University of Washington; SETI Institute; Berkeley SETI Research Center, University of California, Berkeley; National Radio Astronomy Observatory（新墨西哥大学; 华盛顿大学; SETI研究所; 加州大学伯克利分校伯克利SETI研究中心; 国家射电天文台）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出LoFreq-SETI管线，利用Breakthrough Listen算法处理LWA单站数据并计划扩展至LWA Swarm干涉观测，以搜索100 MHz以下低频技术特征，并在快速射电暴数据上验证了处理与空间滤波能力。
AI 中文摘要
搜寻地外智慧生命（SETI）在电磁波谱的各个频段展开，以了解宇宙中智慧生命的普遍性与分布。在射电频段，这项工作聚焦于搜索“技术特征”，即与我们对先进文明的理解相一致的、可观测的技术活动指示物。历史上，1-10 GHz的微波波段一直是搜索这些技术特征的主要频率范围，但近期利用低频射电望远镜（如低频阵列（LOFAR）、默奇森宽场阵列和MeerKAT射电望远镜）开展的SETI实验，已探索了1 GHz以下研究不足的频率范围。然而，最低的射电频率（<100 MHz）在技术特征搜索方面探索更少，尽管大量人类通信信号占据该频段。长波长阵列（LWA）是一个低频（3-88 MHz）干涉仪阵列望远镜合作项目，由分布在美国西南部的偶极子“站点”组成，而LWA Swarm是由相互连接的LWA站点组成的孔径合成望远镜，作为长基线干涉仪运行。在此，我们提出一个窄带技术特征管线，使用Breakthrough Listen Interesting Signal Search算法处理原始波束成形的单站点LWA数据，并概述其计划扩展到来自LWA Swarm的相关可见度数据。我们在有限选择的快速射电暴观测上演示该管线，以评估未来系外行星系统观测活动的数据处理和空间重合滤波。
英文摘要
The search for extraterrestrial intelligence (SETI) is conducted across the electromagnetic spectrum to understand the prevalence and distribution of intelligent life in the universe. At radio frequencies, this effort focuses on searching for "technosignatures", observable indicators of technological activity consistent with our understanding of an advanced civilization. Historically, the microwave regime from 1-10 GHz has been the primary frequency range searched for these technosignatures, but recent SETI experiments utilizing low-frequency radio telescopes, such as the Low Frequency Array (LOFAR), Murchison Widefield Array, and MeerKAT radio telescope have explored the insufficiently studied frequency range below 1 GHz. However, the lowest radio frequencies ($<$100 MHz) have been even less explored for technosignatures, despite significant human communication signals occupying this band. The Long Wavelength Array (LWA) is a low-frequency (3-88 MHz) interferometer array telescope collaboration comprised of dipole 'stations' distributed across the Southwestern United States, and the LWA Swarm is the aperture synthesis telescope consisting of interconnected LWA stations operating as a long baseline interferometer. Here we present a narrowband technosignature pipeline using the Breakthrough Listen Interesting Signal Search algorithm for raw beamformed single-station LWA data and outline its planned extension to correlated visibilities from the LWA Swarm. We demonstrate the pipeline on a limited selection of fast radio burst observations to evaluate the data processing and spatial coincidence filtering for a future observing campaign of exoplanet systems.
