论文标题
FRB121102的持久性对应物的最低频率检测的含义
Implications of the lowest frequency detection of the persistent counterpart of FRB121102
论文作者
论文摘要
语境。迄今为止，重复的FRB121102是唯一与同行相关的半乳酸外快速无线电爆发，这是一个稳定的无线电源，其稳定的无线电源，具有几乎平坦的光谱能量分布（SED），厘米波长。 目标。先前对持续来源的观察到$ 1.6 $ 〜GHz并未显示出频谱转折的迹象。预计吸收最终会在较低的频率下引起转折。可以通过检测自动吸收频率来得出对发射介质物理参数的更好约束。 方法。我们在2017年7月至12月期间使用了巨型米波射电望远镜（GMRT），以低无线电频率降低到$ 400 $ 〜MHz。 结果。即使在$ 400 $ 〜MHz的价格上，源的光谱能量分布仍保持光学薄，光谱指数为$ν^{ - （0.07 \ pm 0.03）} $，类似于银河系中所见。使用通用同步加速器辐射模型，我们获得了对非热等离子体和为其供电的中央发动机的性质的约束。 结论。我们提出了与FRB121102相关的持久源的低频检测。它的特征平面SED降至$ 400 $ 〜MHz。像银河系一样，持续源中的能量主要由瘦素携带。发射等离子体具有$ b <0.01 $ 〜g，其年龄为$> 524 \ left（\ frac {b} {0.01 {\ rm g}}} \ right）^{ - 3/2} $。我们表明，持续源的能量学需要短于36至ms的初始旋转周期，并且中子星的磁场必须超过$ 4.5 \ times 10^{12} $ 〜g。这意味着持续的来源不一定需要磁铁的能量输入。
Context. The repeating FRB121102 is so far the only extra-galactic Fast Radio Burst found to be associated with a counterpart, a steady radio source with a nearly flat spectral energy distribution (SED) in centimeter wavelengths. Aims. Previous observations of the persistent source down to $1.6$~GHz has shown no sign of a spectral turn-over. Absorption is expected to eventually cause a turn-over at lower frequencies. Better constraints on the physical parameters of the emitting medium can be derived by detecting the self-absorption frequency. Methods. We used the Giant Metre-Wave Radio Telescope (GMRT) during the period of July to December 2017 to observe the source at low radio frequencies down to $400$~MHz. Results. The spectral energy distribution of the source remains optically thin even at $400$~MHz, with a spectral index of $ν^{-(0.07 \pm 0.03)}$ similar to what is seen in Galactic plerions. Using a generic synchrotron radiation model, we obtain constraints on properties of the non-thermal plasma and the central engine powering it. Conclusions. We present low-frequency detections of the persistent source associated with FRB121102. Its characteristic flat SED extends down to $400$~MHz. Like Galactic plerions, the energy in the persistent source is carried predominantly by leptons. The emitting plasma has a $B< 0.01$~G, and its age is $> 524 \left(\frac{B}{0.01 {\rm G}} \right)^{-3/2}$. We show that the energetics of the persistent source requires an initial spin period shorter than 36~ms, and the magnetic field of the neutron star must exceed $4.5\times 10^{12}$~G. This implies that the persistent source does not necessarily require energetic input from a magnetar.
