标题： 持续的射电观测结果与FRB20190520B相关的持续射电源提供了关于其起源的见解 显示英文标题

标题： Continued radio observations of the persistent radio source associated with FRB20190520B provides insights into its origin

摘要： 后续研究快速射电暴（FRB）源的持续辐射对于理解其难以捉摸的辐射机制和前身天体的性质至关重要。 本工作展示了与\ourfrb 相关的持续射电源（PRS）的新观测结果。 我们观察到 PRS 亮度逐渐衰减，而在 1.5 GHz 和 3 GHz 频率下，亮度有明暗交替的时期。 此外，我们的低频（$<1$ GHz）观测——这是对该源的首次观测——揭示了光谱拐点的证据，这可以归因于吸收过程。 在磁星风星云模型的框架内，我们的数据将磁星前身天体的年龄限制为$53^{+17}_{-10}$年，这与之前的工作大致一致。 假设观测到的 1.5 GHz 变化是由闪烁驱动的，我们推导出源半径的保守下限为$>0.52$pc，假设屏幕位于 10 kpc 处。 这里展示的观测结果挑战了此前发表的最佳拟合超星云模型对该源的预测。 显示英文摘要

摘要： Follow-up studies of persistent emission from Fast Radio Burst (FRB) sources are critical for understanding their elusive emission mechanisms and the nature of their progenitors. This work presents new observations of the persistent radio source (PRS) associated with \ourfrb. We observe a gradual decay in the PRS brightness, which is punctuated by periods of brightening and dimming at both 1.5 GHz and 3 GHz. Furthermore, our low-frequency ($<1$ GHz) observations-the first for this source-reveal evidence of a spectral break which can be attributed to absorption processes. Interpreted within the framework of the magnetar wind nebula model, our data constrain the age of the magnetar progenitor to $53^{+17}_{-10}$ years, broadly consistent with previous work. Assuming the observed 1.5 GHz variability is driven by scintillation, we derive a conservative lower limit for the source's radius of $>0.52$ pc, for a screen at 10 kpc. The observations presented here challenge the predictions of the previously published best-fit hypernebula model for this source.