以作者查詢圖書館館藏

、以作者查詢臺灣博碩士

、以作者查詢全國書目

、勘誤回報

、線上人數：6

、訪客IP：3.138.141.202

姓名	張智威(Zhi-Wei Zhang)  查詢紙本館藏	畢業系所	天文研究所
論文名稱	中美掩星計畫:自動化光度處理及掩星事件偵測方法之研究 (Automated Photometry Pipeline and Event Detection Algorithm in the TAOS Project)
相關論文	★ 金牛座分子雲外圍之年輕恆星 ★ 濃密分子雲核中的紅外源 ★ 球狀星團NGC288的運動狀態 ★ 利用2微米巡天觀測（2MASS）資料庫分析疏散星團之空間結構 ★ 中美掩星計畫的光度資料分析 ★ 薔薇星雲中的X射線源 ★ 銀河系球狀星團 M13 之中頻寬 CCD 光度測量及其恆星組成 ★ 毫米與次毫米波段的大質量恆星形成 ★ 中美掩星計劃的掩星偵測和星場選擇 ★ 晚期恆星之環星物質的結構研究 ★ 豺狼三分子雲中的年輕星球 ★ 塵粒成長對原行星盤能譜分佈演化之作用 ★ Identification of Herbig Ae/Be Starsin Open Clusters ★ OB星協裡的中低質量星球的形成 ★ 船底座星雲之多波段研究 ★ 從中美掩星計畫資料裡計算古伯帶遮掩背景星的機率以及尋找變星
檔案	[Endnote RIS 格式]    [Bibtex 格式]    [相關文章]   [文章引用]   [完整記錄]   [館藏目錄]   [檢視]  [下載] 本電子論文使用權限為同意立即開放。 已達開放權限電子全文僅授權使用者為學術研究之目的，進行個人非營利性質之檢索、閱讀、列印。 請遵守中華民國著作權法之相關規定，切勿任意重製、散佈、改作、轉貼、播送，以免觸法。
摘要(中)	中美掩星計畫 (Taiwanese-American Occultation Survey; TAOS) 主要的科學目標是對太陽系外圍的小天體（大小約一公里）進行數量的普查。我們利用小天體遮掩遙遠背景恆星時，對其恆星產生光度的瞬時變化來偵測它們。中美掩星計畫擁有四台口徑五十公分的望遠鏡，望遠鏡的光學系統是屬於短焦長 (f/1.9)，再加上 $2048 imes2048$ CCD 相機，可讓觀測的總視場約為三平方度。利用這個廣視場的系統，我們可以使用四台望遠鏡同時監測約兩千顆背景恆星。由於掩星發生時的光度變化極快，我們發展出一套能讀取光度變化高達 5~Hz 頻率的方法，其方法是改變傳統 CCD 相機的讀出方式，進而達成這快速取樣的頻率。這樣的頻率可讓我們偵測到約一公里大的小天體在古伯帶 (Kuiper Belt)。 我們另外發展了一套處理影像光度的軟體，這個特殊的資料處理工具有兩項特點：利用可隨不同觀測影像而移動的遮罩和最佳的測光孔徑，來克服觀測到非常擁擠的星場及星星在影像上的相對移動。這可移式遮罩是由一始觀測時的影像所產生的。其中我們利用 50 顆參考星來決定全部星星的孔徑位置（在不同的觀測影像上），這樣可以避免擁擠星場中，較暗的星星無法正確的量測到光心。另外，最佳的孔徑大小，也可有效的減少來自其他鄰境星星的干擾。這套光度處理的軟體，可以接近即時的速度來處理取得的觀測影像，且不會影響光度的準確度。 得到每顆星的光度資料後，我們利用 emph{Rank Statistics} 的方法，來尋找隱藏在光度資料中的掩星事件。emph{Rank Statistics} 簡單說就是把資料對亮度排序。而這個方法，對於搜尋同時在三台望遠鏡中，只有一個光度點有變化的資料，特別敏感及有效率。另外，如果光度資料中，亮度有隨著時間緩慢變化（三台望遠鏡都有的話），會無法使用這個搜尋方法來找到事件。所以，我們也發展出可以移除光度資料中的低頻率訊號，來防止這情況的發生。 TAOS 從 2005 年二月進行科學觀測，已經取得超過 50~TB 的影像資料及超過一百億個的光度資料點。我們搜尋從 2005 年到 2008 年八月的資料，並未找到任何統計上有可能的事件，雖然如此，我們還是可以依據這批觀測資料，來對大小在 0.5~km 到 28~km 的古伯帶天體，設定數量的上限。
摘要(英)	The Taiwanese-American Occultation Survey (TAOS) aims to conduct the census of Kuiper-Belt objects (KBOs) down to the size of cometary nuclei (a few km) at the outer edge of our solar system. Using the stellar occultation by these KBOs, we can detect them from momentary flux drops in the lightcurves of stars. TAOS comprises an array of four robotic telescopes with fast-optics (f/1.9), each equipped with a 2K x 2K CCD camera, which provides a field-of-view (FOV) of about 3~square degrees. With this wide FOV, TAOS can monitor a couple thousand stars simultaneously and use in a coincidence mode. A data acquisition and analysis scheme has been developed to obtain stellar photometry with sampling rate of 5~Hz by reading out the CCD chip sequentially a few rows of pixels at a time. This high cadence allow us to probe the KBO size down to $sim$1~km. We have developed an automated photometry pipeline with an adaptive aperture mask and an optimal aperture size to deal with the crowded star field and image motion problem. The apertures for measuring stellar photometry fixed on the template mask are built during the initial phase of the pipeline. The aperture for each star on the mask will move to the centroid of star according to the centroids from the 50 bright reference stars for every exposure. This method reduces the uncertainty of the stellar position for dimer stars in crowded fields. And also the optimized aperture size for each star reduces the contamination from the neighbor stars and the noise from sky. The photometry allows us to get time-series measurements in real time and yet not to compromise on the photometric accuracy with these two features. The event detection algorithm based on emph{Rack statistics} has been used for searching the candidates in 3-telescope lightcurves. The algorithm shows it is very efficient to look for a simultaneous one-point flux drop in 3-telescop data and to compute the significance of each candidate event. However, the lightcurves have the flux variations that could undermine this detection algorithm. We therefore implement a filtering method to remove the slow varying trends and the noise variation in the lightcurves. TAOS have been collecting scientific data since February 2005. Over 50~TB raw images have been taken and over 10 billion photometric measurements have been collected. We here present the results from the first 3.5 years of data. No statistically significat events were found that allows us to set an upper bound to the size distribution of KBOs with diameters 0.5~km~$
關鍵字(中)	★ 掩星 ★ 資料處理及分析 ★ 古伯帶天體 ★ 太陽系 ★ 古伯帶	關鍵字(英)	★ Solar System ★ Data Reduction and Analysis ★ Stellar occultation ★
論文目次	1 Introduction 1 1.1 Overview of Kuiper Belt Objects . . . . . . . . . . . . . . . . . . . . . 1 1.1.1 Dynamical Classification and Population . . . . . . . . . . . . . 6 1.1.2 Size Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.2 Overview of the TAOS Project . . . . . . . . . . . . . . . . . . . . . . . 10 1.2.1 Chance Stellar Occultation . . . . . . . . . . . . . . . . . . . . . 10 1.2.2 Scientific Goal & Instrumentation Design . . . . . . . . . . . . . 11 2 TAOS System 17 2.1 Hardwares—Instrumentation . . . . . . . . . . . . . . . . . . . . . . . . 17 2.1.1 Data Acquisition—Zipper-mode Image . . . . . . . . . . . . . . 20 2.2 Softwares—Daemons . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3 Observations 25 3.1 TAOS Star Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3.2 Summary of Data Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 4 Photometric Data Reduction and Analysis 39 4.1 Layout of Photometry . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 4.1.1 Estimation of Sky Background . . . . . . . . . . . . . . . . . . . 42 4.1.2 Determination of Star Position . . . . . . . . . . . . . . . . . . 44 4.1.3 Stellar Flux Calculation . . . . . . . . . . . . . . . . . . . . . . 46 4.1.4 Mask Template . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 4.1.5 Determination of Aperture Size . . . . . . . . . . . . . . . . . . 50 4.2 De-trending Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 5 Event Detection 55 5.1 Ranking and Rank-rank Diagram . . . . . . . . . . . . . . . . . . . . . 55 5.2 Data Quality Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . 57 5.2.1 Method I — Pearson’s Chi-Square Statistics . . . . . . . . . . . 59 5.2.2 Method II — Hypergeometric Statistics . . . . . . . . . . . . . . 60 5.2.3 KS Test—Comparision between Two Distributions . . . . . . . 63 5.3 Rank Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 5.3.1 Probability of Rank Product . . . . . . . . . . . . . . . . . . . . 66 5.3.2 Probability of Continuous Rank Product . . . . . . . . . . . . . 66 5.3.3 Significance of Rank Product . . . . . . . . . . . . . . . . . . . 67 6 Results and Conclusions 73 6.1 Candidate Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 6.2 Efficiency Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 6.3 Size Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 6.4 Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 82 7 Future Work 87
參考文獻	Axelrod, T. S., Alcock, C., Cook, K. H., & Park, H.-S. 1992, in ASP Conf. Ser. 34: Robotic Telescopes in the 1990s, 171–181 Bailey, M. E. 1976, Nature, 259, 290+ Bernstein, G. M., Trilling, D. E., Allen, R. L., Brown, M. E., Holman, M., & Malhotra, R. 2004, Astro. J., 128, 1364 Bianco, F. B. et al. 2009, in preparation Bickerton, S. J., Kavelaars, J. J., & Welch, D. L. 2008, Astro. J., 135, 1039 Brown, M. E., Trujillo, C., & Rabinowitz, D. 2004, Astrophys. J., 617, 645 Brown, M. J. I. & Webster, R. L. 1997, Mon. Not. R. Astron. Soc., 289, 783 Chang, H.-K., King, S.-K., Liang, J.-S., Wu, P.-S., Lin, L. C.-C., & Chiu, J.-L. 2006, Nature, 442, 660 Chang, H.-K. et al. 2007, Mon. Not. R. Astron. Soc., 378, 1287 Chiang, E. I. & Jordan, A. B. 2002, Astro. J., 124, 3430 Cooray, A. & Farmer, A. J. 2003, Astrophys. J., Lett., 587, L125 Da Costa, G. S. 1992, in Astronomical Society of the Pacific Conference Series, Vol. 23, Astronomical CCD Observing and Reduction Techniques, ed. S. B. Howell, 90–104 Davis, D. R. & Farinella, P. 1997, Icarus, 125, 50 Dyson, F. J. 1992, Q. J. R. Astron. Soc., 33, 45 Elliot, J. L. 1979, Ann. Rev. Astron. Astrophys., 17, 445 Elliot, J. L. & Dunham, E. 1979, Nature, 279, 307 Elliot, J. L., Kern, S. D., Clancy, K. B., Gulbis, A. A. S., Millis, R. L., Buie, M. W., Wasserman, L. H., Chiang, E. I., Jordan, A. B., Trilling, D. E., & Meech, K. J. 2005, Astro. J., 129, 1117 Elliot, J. L., Kern, S. D., Gulbis, A. A. S., & Kane, J. F. 2006, in Revista Mexicana de Astronomia y Astrofisica Conference Series, Vol. 26, Revista Mexicana de Astronomia y Astrofisica Conference Series, 1–2 Fernandez, J. A. & Ip, W.-H. 1984, Icarus, 58, 109 Fraser, W. C. et al. 2008, Icarus, 195, 827 Fuentes, C. I., George, M. R., & Holman, M. J. 2009, Astrophys. J., 696, 91 Fuentes, C. I. & Holman, M. J. 2008, Astro. J., 136, 83 Gladman, B., Kavelaars, J. J., Petit, J.-M., Morbidelli, A., Holman, M. J., & Loredo, T. 2001, Astro. J., 122, 1051 Gladman, B., Marsden, B. G., & Vanlaerhoven, C. 2008, Nomenclature in the Outer Solar System, ed. M. A. Barucci, H. Boehnhardt, D. P. Cruikshank, & A. Morbidelli, 43–57 Gomes, R. S. 2003, Icarus, 161, 404 Hillenbrand, L. A., Carpenter, J. M., Kim, J. S., Meyer, M. R., Backman, D. E., Moro-Mart′ın, A., Hollenbach, D. J., Hines, D. C., Pascucci, I., & Bouwman, J. 2008, Astrophys. J., 677, 630 Jewitt, D. & Luu, J. 1993, nat, 362, 730 Jewitt, D. C. & Luu, J. X. 1995, Astro. J., 109, 1867 Jones, R. L., Gladman, B., Petit, J.-M., Rousselot, P., Mousis, O., Kavelaars, J. J., Campo Bagatin, A., Bernabeu, G., Benavidez, P., Parker, J. W., Nicholson, P., Holman, M., Grav, T., Doressoundiram, A., Veillet, C., Scholl, H., & Mars, G. 2006, Icarus, 185, 508 Jones, T. A., Levine, A. M., Morgan, E. H., & Rappaport, S. 2008, Astrophys. J., 677, 1241 Kenyon, S. J. 2002, Publ. Astron. Soc. Pac., 114, 265 Kenyon, S. J. & Bromley, B. C. 2004, Astro. J., 128, 1916 —. 2008, Astrophys. J., Suppl. Ser., 179, 451 Kenyon, S. J. & Luu, J. X. 1999a, Astro. J., 118, 1101 —. 1999b, Astrophys. J., 526, 465 Lehner, M. J. et al. 2009, Publ. Astron. Soc. Pac., 121, 138 Levison, H. F. & Duncan, M. J. 1997, Icarus, 127, 13 Levison, H. F. & Stern, S. A. 2001, Astro. J., 121, 1730 Malhotra, R. 1993, Nature, 365, 819 —. 1995, Astro. J., 110, 420 Millis, R. L., Buie, M. W., Wasserman, L. H., Elliot, J. L., Kern, S. D., & Wagner, R. M. 2002, Astro. J., 123, 2083 Monet, D. G. et al. 2003, Astro. J., 125, 984 Nihei, T. C. et al. 2007, Astro. J., 134, 1596 Pan, M. & Sari, R. 2005, Icarus, 173, 342 Peixinho, N., Lacerda, P., & Jewitt, D. 2008, Astro. J., 136, 1837 Petit, J.-M., Holman, M. J., Gladman, B. J., Kavelaars, J. J., Scholl, H., & Loredo, T. J. 2006, Mon. Not. R. Astron. Soc., 365, 429 Rice, J. 1995, Mathematical statistics and data analysis, ed. J. Burger (Duxbury Press) Roques, F. & Moncuquet, M. 2000, Icarus, 147, 530 Roques, F., Moncuquet, M., Lavilloni`ere, N., Auvergne, M., Chevreton, M., Colas, F., & Lecacheux, J. 2003, Astrophys. J., Lett., 594, L63 Roques, F., Moncuquet, M., & Sicardy, B. 1987, Astro. J., 93, 1549 Roques, F. et al. 2006, Astro. J., 132, 819 Sheppard, S. S., Jewitt, D., & Kleyna, J. 2005, Astro. J., 129, 518 Skrutskie, M. F. et al. 2006, Astro. J., 131, 1163 Stern, S. A. 1996, Astro. J., 112, 1203 Stern, S. A. & Colwell, J. E. 1997, Astro. J., 114, 841 Su, K. Y. L., Rieke, G. H., Stansberry, J. A., Bryden, G., Stapelfeldt, K. R., Trilling, D. E., Muzerolle, J., Beichman, C. A., Moro-Martin, A., Hines, D. C., & Werner, M. W. 2006, Astrophys. J., 653, 675 Trujillo, C. A. & Brown, M. E. 2002, Astrophys. J., Lett., 566, L125 —. 2003, Earth Moon and Planets, 92, 99 Trujillo, C. A., Jewitt, D. C., & Luu, J. X. 2001, Astro. J., 122, 457 Virtanen, J., Tancredi, G., Bernstein, G. M., Spahr, T., & Muinonen, K. 2008, Transneptunian Orbit Computation, ed. M. A. Barucci, H. Boehnhardt, D. P. Cruikshank, & A. Morbidelli, 25–40 Virtanen, J., Tancredi, G., Muinonen, K., & Bowell, E. 2003, Icarus, 161, 419 Yoshida, F. & Nakamura, T. 2007, Planet. Space Sci., 55, 1113 Zhang, Z.-W. et al. 2008, Astrophys. J., Lett., 685, L157 —. 2009, in preparation9.9
指導教授	陳文屏(Wen Ping Chen)	審核日期	2009-8-26
推文	facebook   plurk   twitter   funp   google   live   udn   HD   myshare   reddit   netvibes   friend   youpush   delicious   baidu
網路書籤	Google bookmarks   del.icio.us   hemidemi   myshare