Magnetars are neutron stars with ultrahigh magnetic fields (~10¹⁴–10¹⁵ G). The magnetar SGR J1935+2154 is not only one of the most active magnetars detected so far, but also the unique confirmed source of fast radio bursts. The Gravitational Wave High-energy Electromagnetic Counterpart All-sky Monitor (GECAM) is dedicated to monitor gamma-ray transients all over the sky, including magnetar short bursts. Here we report the GECAM observations of the burst activity of SGR J1935+2154 from 2021 January to 2022 December, which results in a unique and valuable data set for this important magnetar. With a targeted search of GECAM data, 159 bursts from SGR J1935+2154 are detected by GECAM-B while 97 bursts are detected by GECAM-C, including the X-ray burst associated with a bright radio burst. We find that both the burst duration and the waiting time between two successive bursts follow lognormal distributions. The period of burst activity is 134 ± 20 days, thus the burst activity could be generally divided into four active episodes over these two years. Interestingly, the hardness ratio of X-ray bursts tends to be softer during these two years, especially during the active episode with radio bursts detected.

中文翻译：

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GECAM 在 2021 年和 2022 年爆发活跃事件期间对银河磁星 SGR J1935+2154 的观测。I. 突发目录


磁星是具有超高磁场 （~10¹⁴–10¹⁵ G） 的中子星。磁星 SGR J1935+2154 不仅是迄今为止探测到的最活跃的磁星之一，也是唯一确认的快速射电暴来源。引力波高能电磁对应天空监测器 （GECAM） 专门用于监测整个天空的伽马射线瞬变，包括磁星短爆发。在这里，我们报告了 GECAM 对 SGR J1935+2154 从 2021 年 1 月到 2022 年 12 月爆发活动的观测，从而为这颗重要的磁星提供了独特而有价值的数据集。通过对 GECAM 数据的有针对性搜索，GECAM-B 检测到了 SGR J1935+2154 的 159 个爆发，而 GECAM-C 检测到了 97 个爆发，包括与明亮射电暴相关的 X 射线爆发。我们发现，突发持续时间和两个连续突发之间的等待时间都服从对数正态分布。爆发活动周期为 134 ± 20 天，因此爆发活动通常可以分为这两年的四个活跃事件。有趣的是，在这两年中，X 射线暴的硬度比往往更软，尤其是在检测到射电暴的活动事件期间。