AI 中文总结
该研究利用GRBAlpha和VZLUSAT-2立方星，展示了迄今为止最大的伽马射线瞬变样本，包括多种类型瞬变及高红移伽马射线暴。证明纳米卫星可常规监测伽马射线天空，还表明地球周围纳米卫星星座能以一定显著性观测到多数费米/GBM伽马射线暴，并贡献于行星际网络。
AI 中文摘要
我们展示了迄今为止任何立方星任务观测到的最大伽马射线瞬变样本。观测由1U立方星GRBAlpha（最小的天体物理空间天文台）和3U立方星VZLUSAT-2进行。两者都是技术探索者，搭载了基于新型碘化铯闪烁体的探测器，由硅光电倍增管读出。它们在低于550公里的太阳同步低地球轨道上运行约四年。尽管是技术实验，但它们观测到300多个伽马射线瞬变，包括伽马射线暴、太阳耀斑等。其中有两个最亮的伽马射线暴未饱和，还有红移高达z = 4.2的伽马射线暴。GRBAlpha还为行星际网络做出贡献。每周检测到两个瞬变或一个伽马射线暴的检测率证明了对瞬变的定期监测。我们表明，地球周围的纳米卫星星座将以5σ显著性观测到至少60%的费米/GBM伽马射线暴，在3σ水平上超过90%。GRBAlpha和VZLUSAT-2证明低成本和快速开发的纳米卫星任务也可以对伽马射线天空进行常规监测。
英文摘要
We present the largest sample of gamma-ray transients observed by any CubeSat mission so far. Observations were acquired by a 1U CubeSat GRBAlpha, the smallest astrophysical space observatory, and a 3U CubeSat VZLUSAT-2. Both missions were technological pathfinders and carried a novel CsI scintillator-based detector read-out by silicon photomultipliers. They operated on Sun-synchronous low Earth orbits below 550 km for about four years; GRBAlpha between March 2021 and June 2025 while VZLUSAT-2 between January 2022 and November 2025. Despite being technological experiments, they observed over 300 gamma-ray transients including gamma-ray bursts (GRBs), solar flares, soft gamma repeaters and one outburst from an X-ray binary. Among these are the two brightest GRBs ever observed, GRB 221009A and GRB 230307A, without saturation and GRBs at redshifts up to z=4.2. GRBAlpha also contributed to the InterPlanetary Network. Regular monitoring of transients was demonstrated by a detection rate of two transients or one GRB a week and the shortest time between two subsequent detections of only 42 minutes. We show that a constellation of nanosatellites around the Earth would observe at least 60% of Fermi/GBM GRBs with 5$σ$ significance and over 90% at 3$σ$ level. GRBAlpha and VZLUSAT-2 prove that routine monitoring of the gamma-ray sky can also be done by low-cost and quickly developed nanosatellite missions.
Commentsaccepted for publication in ApJ Supplement
