The Galactic magnetar SGR 1935+2154 has been reported to produce the first example of a bright millisecond-duration radio burst (FRB 200428) similar to the cosmological population of fast radio bursts (FRBs). The detection of a coincident bright X-ray burst represents the first observed multiwavelength counterpart of an FRB. However, the search for similar emission at optical wavelengths has been hampered by the high inferred extinction on the line of sight. Here, we present results from the first search for second-timescale emission from the source at near-infrared (NIR) wavelengths using the Palomar Gattini-IR observing system in the J band, enabled by a novel detector readout mode that allows short exposure times of ≈0.84 s with 99.9% observing efficiency. With a total observing time of ≈12 hr (≈47,728 images) during its 2020 outburst, we place median 3σ limits on the second-timescale NIR fluence of ≲18 Jy ms (13.1 AB mag). The corresponding extinction-corrected limit ...

中文翻译：

---

用Palomar Gattini-IR约束SGR 1935 + 2154的二次尺度耀斑的X射线红外光谱指数

据报道，银河系磁星SGR 1935 + 2154产生了明亮的毫秒持续时间无线电脉冲串（FRB 200428）的第一个示例，类似于宇宙学中的快速无线电脉冲串（FRB）。一致的明亮X射线猝发的检测代表了FRB的第一个观察到的多波长对应物。然而，在视线上的高推断消光阻碍了在光学波长下寻找相似发射的研究。在这里，我们介绍了使用J波段的Palomar Gattini-IR观测系统首次搜索源在近红外（NIR）波长下的第二时标发射的结果，该系统由新颖的探测器读出模式实现，可实现较短的曝光时间≈0.84s，观测效率为99.9％。在2020年爆发期间，整个观测时间约为≈12小时（约47,728张图像），我们将中值3σ极限值设置在≲18Jy ms（13.1 AB mag）的第二时间尺度NIR通量上。相应的消光校正极限...