A MILLISECOND INTERFEROMETRIC SEARCH FOR FAST RADIO BURSTS WITH THE VERY LARGE ARRAY
A MILLISECOND INTERFEROMETRIC SEARCH FOR FAST RADIO BURSTS WITH THE VERY LARGE ARRAY
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DOI：
10.1088/0004-637x/807/1/16
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发表时间：
2014-12
期刊：
影响因子：
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通讯作者：
C. Law;G. Bower;S. Burke-Spolaor;S. Burke-Spolaor;B. Butler;E. Lawrence;T. Lazio;C. Mattmann;M. Rupen;A. Siemion;S. VanderWiel
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文献类型：
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作者：
C. Law;G. Bower;S. Burke-Spolaor;S. Burke-Spolaor;B. Butler;E. Lawrence;T. Lazio;C. Mattmann;M. Rupen;A. Siemion;S. VanderWiel
我们报告的第一个毫秒时间尺度的无线电干涉搜索的一类新的瞬态称为快速无线电爆发（FRB）。我们使用超大阵列（VLA）进行了166小时的毫秒成像活动，以检测和精确定位FRB。我们观察到在1.4 GHz，并产生超过256 MHz的带宽与5毫秒的时间分辨率的vibrations。在去色散图像中搜索瞬态，色散测量值从0到3000 pc cm-3。在2013年9月至2014年10月期间对高银河纬度场的观测中没有发现瞬变。对一颗已知脉冲星的观测表明，这些图像通常具有120 mJy beam−1（8？斯托克斯I）在5毫秒，并可以检测和定位在一个广泛的视野瞬态。我们的非检测限制FRB率小于7 × 10 4？>天空-1天-1（95%置信度）高于1.5 Jy ms的通量极限。当用均匀定义重新计算已公布的通量极限时，VLA速率极限与过去的估计一致，该均匀定义包括原射束衰减、色散、脉冲宽度和天空亮度的影响。该计算将FRB率向下修正了2倍，假设脉冲宽度为3 ms，VLA观测值检测到典型FRB的概率约为50%。95%置信度约束需要600小时的类似VLA观测。我们的调查还将FRB的重复率限制在比任何已知的重复毫秒无线电瞬变少2倍。
We report on the first millisecond timescale radio interferometric search for the new class of transient known as fast radio bursts (FRBs). We used the Very Large Array (VLA) for a 166 hr, millisecond imaging campaign to detect and precisely localize an FRB. We observed at 1.4 GHz and produced visibilities with 5 ms time resolution over 256 MHz of bandwidth. Dedispersed images were searched for transients with dispersion measures from 0 to 3000 pc cm−3. No transients were detected in observations of high Galactic latitude fields taken from 2013 September though 2014 October. Observations of a known pulsar show that images typically had a thermal-noise limited sensitivity of 120 mJy beam−1 ( 8 ?> ; Stokes I) in 5 ms and could detect and localize transients over a wide field of view. Our nondetection limits the FRB rate to less than 7 × 10 4 ?> sky−1 day−1 (95% confidence) above a fluence limit of 1.5 Jy ms. The VLA rate limit is consistent with past estimates when published flux limits are recalculated with a homogeneous definition that includes effects of primary beam attenuation, dispersion, pulse width, and sky brightness. This calculation revises the FRB rate downward by a factor of 2, giving the VLA observations a roughly 50% chance of detecting a typical FRB, assuming a pulse width of 3 ms. A 95% confidence constraint would require 600 hr of similar VLA observing. Our survey also limits the repetition rate of an FRB to 2 times less than any known repeating millisecond radio transient.