Multiband Detection of Repeating FRB 20180916B
Multiband Detection of Repeating FRB 20180916B
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DOI：
10.3847/1538-4357/ac6cee
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发表时间：
2021-11
期刊：
影响因子：
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通讯作者：
K. R. Sand;J. Faber;V. Gajjar;D. Michilli;B. Andersen;B. C. Joshi;S. Kudale;M. Pilia;Bryan Br
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文献类型：
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作者：
K. R. Sand;J. Faber;V. Gajjar;D. Michilli;B. Andersen;B. C. Joshi;S. Kudale;M. Pilia;Bryan Br
我们给出了FRB 20180916B的多波段研究，它是一个周期为16.3天的重复源。我们报告了使用升级的巨型米波射电望远镜(300-500 MHz)、加拿大氢强度测绘实验(400-800 MHz)和绿岸望远镜(600-1000 MHz)在3天的观测中分别探测到4次、1次和7次爆发。我们报告了有史以来第一次在800-1000 MHz范围内检测到信号源，并在较低频率下进行了最宽的瞬时带宽检测(200 MHz)。我们在其中一次800兆赫的爆发中发现了30个μS宽结构，这是迄今为止在这一快速射电爆发中检测到的这类结构的最低频率。也有一个明确的迹象表明，在活动周期的早期阶段，源以较高的频率进行高活动。我们发现旋转度量在两年内逐渐减少，而离散度度量没有显著变化。我们得到了关于前身情景、能量分布、发射机制以及发射向下漂移率随频率变化的有用结论。我们的结果强化了多波段观测是研究中继器，甚至是一次性事件的有效方法，以更好地了解它们变化的活动和光谱异常。
We present a multiband study of FRB 20180916B, a repeating source with a 16.3 day periodicity. We report the detection of four, one, and seven bursts from observations spanning 3 days using the upgraded Giant Metrewave Radio Telescope (300–500 MHz), the Canadian Hydrogen Intensity Mapping Experiment (400–800 MHz) and the Green Bank Telescope (600–1000 MHz), respectively. We report the first ever detection of the source in the 800–1000 MHz range along with one of the widest instantaneous bandwidth detections (200 MHz) at lower frequencies. We identify 30 μs wide structures in one of the bursts at 800 MHz, making it the lowest frequency detection of such structures for this fast radio burst thus far. There is also a clear indication of high activity of the source at a higher frequency during earlier phases of the activity cycle. We identify a gradual decrease in the rotation measure over two years and no significant variations in the dispersion measure. We derive useful conclusions about progenitor scenarios, energy distribution, emission mechanisms, and variation of the downward drift rate of emission with frequency. Our results reinforce that multiband observations are an effective approach to study repeaters, and even one-off events, to better understand their varying activity and spectral anomalies.