论文标题
旋转测量重复快速无线电爆发源FRB 121102的演变
Rotation Measure Evolution of the Repeating Fast Radio Burst Source FRB 121102
论文作者
论文摘要
重复的快速无线电爆发源FRB 121102已显示出具有异常高且可变的法拉第旋转度量（RM），必须在其主机银河系中及其本地环境中或可能在其本地环境中施加。在红移（$ z = 0.193 $）的源参考框架中，RM从$ 1.46 \ times10^5 $ 〜rad〜m $ $ $ $^{ - 2} $降至$ 1.33 \ times10^5 $ 〜rad〜m $ $^{ - 2} $ 2017年1月至8月之间，显示了$ \ sim $ \ sim200 $^rad $^rad $^rad $^rad $^m.在这里，我们从Arecibo 305-M射电望远镜，Effelsberg 100-m和Karl G. Jansky的爆发检测中介绍了16个FRB 121102 RMS，非常大的阵列，提供了2。5年的时间内FRB 121102 RM的记录。我们的观察结果显示了RM的下降趋势，尽管趋势不是线性的，平均下降了15 \％$^{ - 1} $，并且是$ \ sim9.7 \ sim9.7 \ times10^4 $ 〜rad〜m $ $ $^{ - 2} $，在2019年8月的最新时期。在MJDS 58215--58247之间还观察到了周$^{ - 1} $。已经提出了一个数十年历史的中子星，这些星星嵌入了仍然紧凑的超新星残留物或巨大黑洞附近的中子恒星中，并提出了其积聚的圆环来解释高RMS。我们将观察到的RMS与描述源自超新星残留物中的FRB的RM演化的理论模型进行了比较。 FRB 121102的年龄尚不清楚，我们发现模型在2017年首次可用RM测量时的源年龄为$ \ sim6-17 $〜年。我们还与降低银河中心磁场RM的比较，PSR J1745--2900。
The repeating fast radio burst source FRB 121102 has been shown to have an exceptionally high and variable Faraday rotation measure (RM), which must be imparted within its host galaxy and likely by or within its local environment. In the redshifted ($z=0.193$) source reference frame, the RM decreased from $1.46\times10^5$~rad~m$^{-2}$ to $1.33\times10^5$~rad~m$^{-2}$ between January and August 2017, showing day-timescale variations of $\sim200$~rad~m$^{-2}$. Here we present sixteen FRB 121102 RMs from burst detections with the Arecibo 305-m radio telescope, the Effelsberg 100-m, and the Karl G. Jansky Very Large Array, providing a record of FRB 121102's RM over a 2.5-year timespan. Our observations show a decreasing trend in RM, although the trend is not linear, dropping by an average of 15\% year$^{-1}$ and is $\sim9.7\times10^4$~rad~m$^{-2}$ at the most recent epoch of August 2019. Erratic, short-term RM variations of $\sim10^3$~rad~m$^{-2}$ week$^{-1}$ were also observed between MJDs 58215--58247. A decades-old neutron star embedded within a still-compact supernova remnant or a neutron star near a massive black hole and its accretion torus have been proposed to explain the high RMs. We compare the observed RMs to theoretical models describing the RM evolution for FRBs originating within a supernova remnant. FRB 121102's age is unknown, and we find that the models agree for source ages of $\sim6-17$~years at the time of the first available RM measurements in 2017. We also draw comparisons to the decreasing RM of the Galactic center magnetar, PSR J1745--2900.
