arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1901.04524astro-ph.HE
收藏

频率低至400兆赫的快速射电暴观测

Observations of Fast Radio Bursts at Frequencies down to 400 Megahertz

FRB Collaboration, Mandana Amiri, Kevin Bandura, Mohit Bhardwaj, Paula Boubel, Michelle M. Boyce, Patrick J. Boyle, Charanjot Brar, Maya Burhanpurkar, Pragya Ch… 展开作者

FRB Collaboration, Mandana Amiri, Kevin Bandura, Mohit Bhardwaj, Paula Boubel, Michelle M. Boyce, Patrick J. Boyle, Charanjot Brar, Maya Burhanpurkar, Pragya Chawla, Jean F. Cliche, Davor Cubranic, Meiling Deng, Nolan Denman, Matthew Dobbs, M. Fandino, Emmanuel Fonseca, Bryan M. Gaensler, Adam J. Gilbert, Utkarsh Giri, Deborah C. Good, Mark Halpern, David Hanna, Alexander S. Hill, Gary Hinshaw, C. Höfer, Alexander Josephy, Victoria M. Kaspi, Thomas L. Landecker, Dustin A. Lang, Kiyoshi W. Masui, Ryan Mckinven, Juan Mena-Parra, Marcus Merryfield, Nikola Milutinovic, Charles Moatti, Arun Naidu, Laura B. Newburgh, Cherry Ng, Chitrang Patel, Ue-Li Pen, Tristan Pinsonneault-Marotte, Ziggy Pleunis, Masoud Rafiei-Ravandi, Scott M. Ransom, Andre Renard, Paul Scholz, J. R. Shaw, Seth R. Siegel, Kendrick M. Smith, Ingrid H. Stairs, Shriharsh P. Tendulkar, Ian Tretyakov, Keith Vanderlinde, Prateek Yadav

摘要:

快速射电暴(FRB)是一种高度分散的毫秒级射电闪光,可能来自银河系之外。这种现象是在1.4 GHz附近的射频发现的,迄今为止,在一个高达8 GHz的情况下观察到这种现象,但尽管在低频进行了大量的研究,但在700 MHz以下的情况下观察到这种现象。在这里,我们报告检测FRB在射频低至400 MHz,加拿大氢强度测绘实验(CHIME)使用CHIME/FRB仪器。我们提出了13个FRB检测望远镜预调试阶段,当我们的灵敏度和视场尚未在设计规格。在多个事件中,可以看到低至400兆赫的发射,这是我们敏感的最低射频。FRB表现出各种各样的时间散射行为,其中大多数显著散射,有些甚至在我们的最低频率下也明显未散射到测量不确定性范围内。在这里报告的13个事件中,有一个事件的离散度最低,这意味着它是已知的最接近的事件之一,另一个事件显示出多个重复爆发,如配套论文所述。我们的低散射事件表明,在低于400兆赫的射频下探测FRB的努力最终将取得成功。我们的样本的整体散射特性表明,FRB作为一类优先位于环境中,散射无线电波更强烈的比弥漫的星际介质(ISM)在银河系。

英文摘要:

Fast radio bursts (FRBs) are highly dispersed millisecond-duration radio flashes likely arriving from far outside the Milky Way galaxy. This phenomenon was discovered at radio frequencies near 1.4 GHz and to date has been observed in one case at as high as 8 GHz, but not below 700 MHz in spite of significant searches at low frequencies. Here we report detections of FRBs at radio frequencies as low as 400 MHz, on the Canadian Hydrogen Intensity Mapping Experiment (CHIME) using the CHIME/FRB instrument. We present 13 FRBs detected during a telescope pre-commissioning phase, when our sensitivity and field-of-view were not yet at design specifications. Emission in multiple events is seen down to 400 MHz, the lowest radio frequency to which we are sensitive. The FRBs show a variety of temporal scattering behaviours, with the majority significantly scattered, and some apparently unscattered to within measurement uncertainty even at our lowest frequencies. Of the 13 reported here, one event has the lowest dispersion measure yet reported, implying it is among the closest yet known, and another has shown multiple repeat bursts, as described in a companion paper. Our low-scattering events suggest that efforts to detect FRBs at radio frequencies below 400 MHz will eventually be successful. The overall scattering properties of our sample suggest that FRBs as a class are preferentially located in environments that scatter radio waves more strongly than the diffuse interstellar medium (ISM) in the Milky Way.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑