Targeted and all-sky search for nanosecond optical pulses at Harvard-Smithsonian
Targeted and all-sky search for nanosecond optical pulses at Harvard-Smithsonian
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哈佛史密森学会有针对性地进行纳秒光脉冲全天搜索
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
Joseph M. Zajac
中科院分区：
文献类型：
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作者：
P. Horowitz;C. Coldwell;A. Howard;D. Latham;R. Stefanik;Jonathan Wolff;Joseph M. Zajac
我们建立了一个系统，用于检测来自约 10,000 颗类太阳恒星的目标列表中的纳秒脉冲光信号，并在两年的运行期间进行了约 20,000 次观测。哈佛/史密森橡树岭天文台（阿加西站）的 1.5m 卡塞格林焦平面上的一对混合雪崩光电探测器通过分束器进行馈电，同时触发亚纳秒分辨率的脉冲宽度和强度测量。灵活的网络数据库，加上非常低的背景重合率（每晚大约 1 个事件），可以轻松地对遥远的数据进行排序，以搜索任何候选恒星的重复事件。普林斯顿大学 0.9m 卡塞格伦望远镜上的一个相同的系统很快将开始与我们同步的观测。这些甚至可以明确识别单个脉冲。我们正在计划使用专用的 1.8m f/2.4 球形玻璃光桶和部署在一对匹配焦平面中的像素化光电倍增管阵列进行全天空光脉冲搜索。天空像素为 1.5 角分平方，在凌日模式下细分出 1.6 x 0.2 度的天空斑块，在大约 150 个晴朗的夜晚覆盖北方天空。快速定制 IC 电子器件将监控相应像素是否存在纳秒时间尺度的一致光脉冲，从而触发闪光数字化波形的存储。
We have built a system to detect nanosecond pulsed optical signals from a target list of some 10,000 sun-like stars, and have made some 20,000 observations during its two years of operation. A beamsplitter feeds a pair of hybrid avalanche photodetectors at the focal plane of the 1.5m Cassegrain at the Harvard/Smithsonian Oak Ridge Observatory (Agassiz Station), with a coincidence triggering measurement of pulse width and intensity at sub-nanosecond resolution. A flexible web-enabled database, combined with mercifully low background coincidence rates (approximately 1 event per night), makes it easy to sort through far-flung data in search of repeated events from any candidate star. An identical system will soon begin observations, synchronized with ours, at the 0.9m Cassegrain at Princeton University. These will permit unambiguous identification of even a solitary pulse. We are planning an all-sky search for optical pulses, using a dedicated 1.8m f/2.4 spherical glass light bucket and an array of pixelated photomultipliers deployed in a pair of matched focal planes. The sky pixels, 1.5 arcmin square, tessellate a 1.6 by 0.2 degree patch of sky in transit mode, covering the Northern sky in approximately 150 clear nights. Fast custom IC electronics will monitor corresponding pixels for coincident optical pulses of nanosecond timescale, triggering storage of a digitized waveform of the light flash.