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題名 | 「中美掩星計畫」的掩星偵測和星場選擇=Occultation Detection and Field Selection for the TAOS Project |
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作者 | 黃裕仁; 陳文屏; 張智威; Huang, Yu-jen; Chen, Wen-ping; Zhang, Zhi-wei; |
期刊 | 臺北天文館學報 |
出版日期 | 20041200 |
卷期 | 2 民93.12 |
頁次 | 頁62-69 |
分類號 | 323.2 |
語文 | chi |
關鍵詞 | 太陽系; 古柏帶天體; 觀測技術; 統計分析; Solar system; Kuiper-belt objects; Observational technique; Statistical analysis; |
中文摘要 | 中美掩星計畫 (Taiwan-America Occultation Survey; 簡稱TAOS) 的目的在統計古柏帶天體的數量與空間分佈。TAOS並不對古柏帶天體進行直接成像觀測,而是利用它們遮掩遠方背景恆星時,造成背景恆星光度衰減,藉此原理以統計方法來估計古柏帶天體的數量。 TAOS 之電子相機利用特殊讀取方式,可以取得達數赫茲的快速光度資料,並藉由多臺望遠鏡觀測提高事件偵測可信度。本研究以TAOS影像參數,利用MATLAB 套裝程式撰寫影像模擬程式。一方面幫助瞭解 TAOS 特殊取樣影像的特性,有助於開發光度分析程式;另方面藉由模擬掩星事件,評估利用無母數排序統計方法來偵測掩星事件的可行性。模擬程式的另個應用,在於估計星體光度受到鄰近星干擾的程度。我們引入「掩星偵測值」參數,量化某星體被排序法偵測到掩星的機率。藉由比較各星場中整體「掩星偵測值」的大小,便可以評估適合TAOS 監測的星場,提高掩星事件的偵測率。 |
英文摘要 | The Taiwan-America Occultation Survey (TAOS) aims to conduct a census of the Kuiper-belt objects (KBOs). Rather than direct imaging, the TAOS project monitors stellar light curves for chance stellar occultation by KBOs. Stellar occultation events by KBOs are expected to be extremely rare and each event would last in less than a second. The TAOS project makes use of a special CCD readout scheme to achieve stellar photometry sampled at a few hertzs, and requires coincidence detection by multiple telescopes to accredit an event. We report our effort to develop an image acquisition simulator program, written with MATLAB, which provides useful guidance for photometry pipelines, and for analysis of multiple-telescope data by nonparametric rank statistics. A specific application of our simulator is target field selection. We parameterize for each star field a "detectability" --- the likelihood number of occultation events detectable given the stellar distribution in a field --- with which one target field can be prioritized against another. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。