本篇論文將描述兩個低核密度球狀星團：NGC6144、以及E3的X光與可見光觀測及分析，並藉此討論其中X光源數量與球狀星團內，恆星經由遭遇生成雙星系統、以及原生雙星系統的關係。我們使用錢卓拉X光望遠鏡的觀測資料，經由CIAO軟體分析；以及使用哈伯太空望遠鏡尋找其可見光之對應物，並經由DOLPHOT軟體分析。在NGC614以及E3各自的半質量半徑內，我們分別偵測到NGC6144有六個X光源；而E3有三個X光源。然而在我們的觀測中，NGC6144估計將有4-5個X光源來自背景；E3則會有2個X光源來自背景，從統計上的結果，我們無法排除所有偵測到的光源皆不是來自背景。因為觀測時間與儀器敏感度，我們只會偵測到光度(在光子能量介於0.3-10千電子伏範圍內) 大於每秒 1.7×10^30 爾格的光源。經由分析，我們確定在NGC6144中有1-2組激變變星(CVs)及一組活躍雙星(ABs)；在E3中則有一組疑似激變變星。這些結果為原生雙星的重要證據。

We report on the Chandra X-ray Observatory and Hubble Space Telescope observation of two low core density globular clusters, NGC6144 and E3. Within the half-mass radius and at a detection limit of L_X = 1.7 × 10^30 ergs/s , we found 6 X-ray sources in NGC6144, of which 4-5 are expected to be background sources; and 3 X-ray sources within the half-mass radius of E3, of which 2 are expected to be background sources. Therefore, we cannot exclude that all our sources are background sources. However, combining the results from X-ray and optical observations, we found that 1-2 sources in NGC6144 and 1 source in E3 are likely to be cataclysmic variables and that 1 source in NGC6144 is an active binary, based on the X-ray and optical properties. The number of faint X-ray sources in NGC6144 and E3 found with Chandra and HST is higher than a prediction based on collision frequency, but is closer to that based on mass. Our observations strongly suggest that the compact binary systems in NGC6144 and E3 are primordial in origin.

§ Chapter 1: Introduction
1.1 Binary Stars in Globular Clusters
1.2 Quiescent Low Mass X-Ray Binaries
1.3 Cataclysmic Variables
1.4 Active Binaries
1.5 Millisecond Pulsars
1.6 Stellar Encounter and Primordial Binaries
1.7 Outline of the thesis

§ Chapter 2: Instrumentations and Observations
2.1 Observatory and Target Selection
2.2 Chandra X-ray Observatory
2.3 Hubble Space Telescope
2.4 Globular Cluster NGC6144
2.5 Globular Cluster E3

§ Chapter 3: X-ray Data Reduction and Analysis
3.1 Data Analysis and Sources Detection
3.2 Spectral Fitting and Light Curves

§ Chapter 4: Optical Data Reduction and Analysis
4.1 Photometry
4.2 Astrometry
4.2.1 Astrometry of NGC6144
4.2.2 Astrometry of E3

§ Chapter 5: Sources Identification
§ Chapter 6: Discussion
§ Appendixes
§ References

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