标题： 一个频繁重复的快速射电暴源与磁星模型的危机 显示英文标题

标题： A prolific repeating fast radio burst source and a crisis of the magnetar model

摘要： 磁星被广泛认为是快速射电暴（FRB）的中心引擎，能够通过磁场能量释放驱动相干射电辐射。爆发能量的积累可作为探测FRB能量引擎性质的探针。当前对重复暴源的观测尚未提供足够的约束来限定磁星模型的磁场能量预算。在此，我们报告在最近一次活跃期间，通过五百米口径球面射电望远镜（FAST）监测观测，在214天内从超活跃重复源FRB 20240114A中检测到11,553次爆发，其峰值爆发率高达729小时$^{-1}$，高于监测观测的检测阈值。这代表了来自单一FRB源的最大记录爆发样本，其爆发次数超过任何已知重复暴源的四倍以上，并超过了迄今为止所有已发表爆发的累计总数。假设典型的无线电效率为$10^{-4}$，束流因子为0.1，该源的总各向同性爆发能量超过了典型磁星二极磁场能量的86%，该磁星的极表面磁场为$10^{15}$ G，半径为$10^6$ cm。该源的总能量释放比其他已知重复暴源高出一个半数量级。我们进一步提供了对潜在磁星磁矩的最严格下限，为$\bf{4.7\times10^{32}}$ G cm$^3$。这些发现表明，要么中心引擎以异常高的无线电效率发射，要么具有较小的束流因子，或者它应该是一个比当前磁星模型中通常考虑的更强大的致密天体。 显示英文摘要

摘要： Magnetars are widely considered to be the central engine of fast radio bursts (FRBs), capable of driving coherent radio emission through magnetic energy release. The accumulation of burst energy can be employed as a probe to reveal the nature of FRB energy engine. Current observations of repeaters have not yet provided sufficient constraints on the magnetic energy budget for magnetar models. Here we report 11,553 bursts detected from the hyper-active repeating source FRB 20240114A over 214 days during a recent active episode, with a peak burst rate as high as 729 hr$^{-1}$, above the detection threshold of the monitoring observations using Five-hundred-meter Aperture Spherical radio Telescope (FAST). This represents the largest recorded burst sample from a single FRB source, comprising more than four times as many bursts as any previously known repeater and exceeding the cumulative total of all published bursts to date. Assuming a typical value of radio efficiency of $10^{-4}$ and a beaming factor of 0.1, the estimated total isotropic burst energy of this source exceeds 86\% of the dipolar magnetic energy of a typical magnetar with a polar surface magnetic field of $10^{15}$ G and a radius of $10^6$ cm. The total energy release of this source is about one and a half orders of magnitude higher than that of other known repeaters. We further provide the most stringent lower limit of $\bf{4.7\times10^{32}}$ G cm$^3$ on the magnetic moment of the underlying magnetar. The findings suggest that either the central engine emits with exceptionally high radio efficiency, possesses a small beaming factor, or it should be a more powerful compact object than typically considered in current magnetar models.