- 學位論文
尋找天蝎座X-1中子星的自旋週期
Search for the Rotation Period of the Neutron Star in Scorpius X-1
摘要
摘要 天蝎座X-1是天空中除了太陽以外最亮的X光物體。我們藉著觀察它的X光，找尋天蠍座裡面中子星的自轉週期。雖然人們已經發現天蠍座X-1有許多類週期振盪(quasi-periodic oscillations, QPOs)，但是它的中子星自旋週期仍然未被找到。我們利用H-test和Epoch-folding χ2 test去研究天蝎座X-1可能的自旋週期訊號。我們使用RXTE人造衛星上面的PCA在2009年觀測的資料(資料編號 94318)，每2×10^-5HZ為間隔，搜尋250Hz到650Hz範圍內的週期訊號。這筆資料的傅立葉寬度為1.1×10^-4HZ。在我們的分析中，並沒有找到明顯的自旋週期訊號。藉著觀測到的H值，我們給出2倍標準差信心水準的週期訊號通量上限為 5.6×10^-3個光子/平方公分/每秒。在觀測中的平均通量是5個光子/平方公分/每秒。週期訊號通量佔總通量的比例上限為1.1×10^-3。
並列摘要
Abstract Scorpius X-1 (Sco X-1) is the brightest extra-solar X-ray source in the sky. We present the result of searches for the neutron star rotation period in the X-ray emission from Sco X-1. Although a rich spectrum of quasi-periodic pulsations has been found in Sco X-1,the rotation signature of its neutron star has been being missing. We conducted H-test and epoch-folding Chi-square test to investigate possible periodic signals of Sco X-1. The Obs. ID 94318 data we used were obtained by the Proportional Counter Array (PCA) on board the Rossi X-ray Timing Explorer (RXTE). The frequency range searched is from 250 Hz to 650 Hz with a step of 2×10^−5. The Fourier width of the data we used is 1.1×10^−4. We did not find significant enough periodicity in our analysis. The 2σ upper limit to the pulsed flux based on the observed H is 5.6×10−3 photons cm^−2 s^−1. The total flux is 5.0 photons cm^−2 s^−1 during the observation. The upper limit to the pulsed fraction is 1.1×10^−3.