本文選題：星系 + 星系團�。� 參考：《南京師范大學》2011年碩士論文

【摘要】：研究星系的恒星形成性質(zhì)已成為近十年來河外天體物理學最熱門的研究領(lǐng)域之一。探索星系團中成員星系的恒星形成性質(zhì)及其與星系形態(tài)、環(huán)境以及其他一些星系物理特性之間的關(guān)系,有助于我們了解星系的形成和演化,從而了解整個宇宙的形成和演化的歷史。 多波段觀測數(shù)據(jù)表明,位于南半天區(qū)的cD星系團A85(z=0.055)是一個處于并合中的星系團�；赟loan Digital Sky Survey (SDSS)提供的242個成員星系的光譜,我們利用演化星族合成代碼STARLIGHT,獲得了這些星系的恒星形成歷史,由此分析星系的恒星形成性質(zhì)與局域空間密度之間的關(guān)系。我們發(fā)現(xiàn)：隨著星系局域而密度的增加,星系的金屬豐度也在增加,星系的年齡相對較大；在整個恒星形成歷史時期,密度高的區(qū)域星系的恒星形成率高；在最近的24.5Myr,低密度區(qū)域中星系的恒星形成率相對較高,高密度區(qū)域的星系中則幾乎沒有發(fā)現(xiàn)恒星形成；密度低的區(qū)域星系特征恒星形成率總是大于密度高區(qū)域的星系特征恒星形成率。此外,質(zhì)量越大的星系在最近24.5Myr的特征恒星形成率越�。毁|(zhì)量越小的星系最近的特征恒星形成率越高。 本文還對星系團A2255中成員星系的恒星形成性質(zhì)做了對比研究。我們利用基于連續(xù)譜擬合的STARLIGHT方法對來自SDSS的數(shù)據(jù)做了處理,與利用兼顧發(fā)射線與連續(xù)譜的MPA/JHU方法得出的數(shù)據(jù)做了對比性研究。我們發(fā)現(xiàn)：(1)這兩種方法估計出的恒星質(zhì)量非常一致；(2) STARLIGHT獲得的24.5Myr內(nèi)的特征恒星形成率與MPA/JHU估計的特征恒星形成率也基本吻合。(3)我們還比較了兩種方法獲得的特征恒星形成率隨著投影距離之間的關(guān)系,得到了與過去研究一致的環(huán)境效應。(4)由STARLIGHT給出的光度權(quán)重下的平均恒星年齡和連續(xù)譜參數(shù)Dn(4000)具有很強的相關(guān)性。(5)利用STARLIGHT獲得的金屬豐度和MPA/JHU獲得的恒星質(zhì)量參數(shù),驗證了前人提出的星系金屬豐度和星系質(zhì)量的相關(guān)性。
[Abstract]:The study of star formation in galaxies has become one of the hottest research fields in extragalactic astrophysics in recent ten years. Exploring the star forming properties of galaxies that are members of the cluster and their relationship with the shape, environment and other physical properties of galaxies will help us to understand the formation and evolution of galaxies. In order to understand the formation and evolution of the entire history of the universe. The multi-band observations show that the CD cluster A85ZN 0.055, located in the southern half day region, is a cluster in the mergence. Based on the spectra of 242 member galaxies provided by Sloan Digital Sky Survey / SDSS, the star formation history of these galaxies is obtained by using the evolutionary star family synthesis code STARLIGHT.The relationship between star formation properties and local spatial density of galaxies is analyzed. We find that with the increase of the local and density of galaxies, the metal abundance of galaxies increases, and the age of galaxies is relatively large, and the high density regional galaxies have high star formation rate during the whole history of star formation. In the most recent area of 24.5Myr, star formation rates are relatively high in galaxies in low-density regions, and almost no star formation is found in galaxies in high-density regions. The characteristic star formation rate of low density region is always higher than that of high density region. In addition, the higher the mass, the smaller the characteristic star formation rate of the nearest 24.5Myr, and the higher the nearest characteristic star formation rate of the smaller mass galaxy. The star formation properties of galaxies in cluster A 2255 are also studied in this paper. The STARLIGHT method based on continuous spectrum fitting is used to process the data from SDSS, and a comparative study is made with the data obtained by using the MPA/JHU method which combines the emission line and the continuous spectrum. We find that the two methods estimate the star mass is very consistent) the characteristic star formation rate in 24.5Myr obtained by STARLIGHT is also basically consistent with the characteristic star formation rate estimated by MPA/JHU.) We also compare the characteristics obtained by the two methods. The relationship between star formation rate and projection distance, The results show that the environmental effects consistent with previous studies, such as the average star age and the continuous spectral parameter Dnn4 given by STARLIGHT, have a strong correlation. 5) the metal abundance obtained by STARLIGHT and the stellar mass parameters obtained by MPA/JHU are highly correlated. The correlation between metallic abundance and galactic mass was verified.
【學位授予單位】：南京師范大學
【學位級別】：碩士
【學位授予年份】：2011
【分類號】：P152

【參考文獻】

相關(guān)期刊論文 前1條

1 萬吉莉;袁啟榮;;星系團Abell 85的動力學子結(jié)構(gòu)[J];天文學報;2010年03期

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本文編號：1935413