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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/80386


    Title: Color Variabilities of QSOs at z = 0.3 - 1.2
    Authors: 陸勇志;Loke, Young Tzee
    Contributors: 天文研究所
    Keywords: 類星體;活躍星系核;星系;QSO;AGN;Galaxy
    Date: 2019-08-19
    Issue Date: 2019-09-03 14:27:58 (UTC+8)
    Publisher: 國立中央大學
    Abstract: 我們研究了類星體的顏色變化的特性。我們交叉比對史隆數位化巡 (SDSS) 所釋出的第七版資料 (DR 7) 和第十二版資料 (DR 12) 的類星體目錄,選出 608 個在兩個版本都有觀測資料且紅移在 0.3 到 1.2 之間的類星體。我們選用在靜止坐標系下 3000 埃與 4000 埃的光通量密度比值來定義顏色值。我們透過比較兩個版本類星體的顏色值來定義顏色變化。我們發現在靜止坐標系下,類星體的顏色變化分佈類似常態分佈,但部分類星體在數年的時間尺度下有著明顯的顏色變化。另外,我們還發現了八個類星體的光譜變化可以被塵埃紅化現象來解釋。我們的結果也顯示了類星體的顏色變化可能存在多個物理機制。;We investigate the color variabilities of QSOs at z = 0.3 – 1.2. We selected the sample of 608 QSOs, which have multi-epoch spectra in both the Sloan Digital Sky Survey (SDSS) Data Released 7 (DR7) and Data Released 12 (DR12). We defined the spectral color ofthe QSOs by the ratio of flux densities of 3000 Å to 4000 Å in the rest frame. In each sample, the color variability is defined by the differences of color in DR7 and DR12.We find that the color variabilities show a Gaussian distribution with some QSOs displaying significant color changes within the timescale of a few years. We find that the spectral variabilities of eight color-change QSOs could be explained by dust reddening. Our results also show that the color variabilities of QSOs might originate from more than one physics mechanisms.
    Appears in Collections:[天文研究所] 博碩士論文

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