ALL TRANSIENTS, ALL THE TIME: REAL-TIME RADIO TRANSIENT DETECTION WITH INTERFEROMETRIC CLOSURE QUANTITIES
ALL TRANSIENTS, ALL THE TIME: REAL-TIME RADIO TRANSIENT DETECTION WITH INTERFEROMETRIC CLOSURE QUANTITIES
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DOI：
10.1088/0004-637x/749/2/143
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发表时间：
2011-12
期刊：
影响因子：
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通讯作者：
C. Law;G. Bower
中科院分区：
文献类型：
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作者：
C. Law;G. Bower
我们展示了一种新的技术，用于检测无线电瞬变的基础上干涉关闭量。该技术使用双谱，即围绕干涉仪的基线的闭环的振动的产物。双谱是校准独立的，抗干扰，计算效率高，因此它可以内置到实时瞬态检测的放大器。我们的技术可以找到天体瞬变的视野中的任何地方，并将其定位到角秒精度。在卡尔G。Jansky甚大阵列（VLA），这样的系统将有一个高的调查速度和5σ灵敏度为38 mJy的10 ms的时间尺度与1 GHz的带宽。在大量的干涉仪数据中将分散的毫秒脉冲定位到角秒精度的能力具有几个独特的科学应用。定位来自银河系恒星的单个脉冲将有助于找到定义其物理特性的X射线对应物，而寻找河外瞬变的宿主星系将用单个分散脉冲测量星系际介质的电子密度。系外行星和活动恒星具有明显的毫秒变化性，可用于识别它们并探测它们的磁层。利用艾伦望远镜阵列和VLA的毫秒级时间尺度的双谱，我们证明了双谱可以检测到色散脉冲，并能抑制局部干扰。双谱的计算和数据效率将有助于下一代无线电干涉仪在一系列时间尺度上找到瞬态。
We demonstrate a new technique for detecting radio transients based on interferometric closure quantities. The technique uses the bispectrum, the product of visibilities around a closed loop of baselines of an interferometer. The bispectrum is calibration independent, resistant to interference, and computationally efficient, so it can be built into correlators for real-time transient detection. Our technique could find celestial transients anywhere in the field of view and localize them to arcsecond precision. At the Karl G. Jansky Very Large Array (VLA), such a system would have a high survey speed and a 5σ sensitivity of 38 mJy on 10 ms timescales with 1 GHz of bandwidth. The ability to localize dispersed millisecond pulses to arcsecond precision in large volumes of interferometer data has several unique science applications. Localizing individual pulses from Galactic pulsars will help find X-ray counterparts that define their physical properties, while finding host galaxies of extragalactic transients will measure the electron density of the intergalactic medium with a single dispersed pulse. Exoplanets and active stars have distinct millisecond variability that can be used to identify them and probe their magnetospheres. We use millisecond timescale visibilities from the Allen Telescope Array and VLA to show that the bispectrum can detect dispersed pulses and reject local interference. The computational and data efficiency of the bispectrum will help find transients on a range of timescales with next-generation radio interferometers.