高和低红移活动星系核CⅣ宽线区动力学  

The Dynamics of C Ⅳ Broad Emission Line Region in Low and High Redshift AGN Samples

作　　者：高姗 王慧元[1] GAO Shan;WANG Hui-yuan(Department of Astronomy,University of Science and Technology,Hefei 230026,China)

机构地区：[1]中国科学技术大学天文学系,合肥230026

出　　处：《天文学进展》2020年第3期311-332,共22页Progress In Astronomy

基　　金：国家自然科学基金(11733004,11421303,11890693,11522324)。

摘　　要：基于斯隆巡天的高红移类星体以及IUE和HST低红移活动星系核光谱样本,仔细分析CⅣ的等值宽度、半高全宽、蓝移不对称参数和活动星系核吸积状态之间的相关性。结果得到,当爱丁顿比Lbol/LEdd<0.1时,CⅣ发射线类似于低电离线,接近位力化状态;而Lbol/LEdd>0.1时,呈现出明显的外流特征。这表明Lbol/LEdd>0.1时,辐射压对宽线区云团运动状态的影响变得比较重要。In this paper, we present a detailed study on the dynamics of C Ⅳ broad emission line region, and its implication to the line formation and its connection to the accretion processes. Our AGN sample is composed of two subsamples, one is taken from SDSS(high-redshift sample), and the other is taken from the IUE and HST observation(low-redshift sample). We use a blueshift and asymmetry index(BAI) of C Ⅳ line to indicate the outflow strength, we also measure the equivalent width(EW) and full width at half-maximum(FWHM). We confirm previous results: in high-reshift sample, C Ⅳ and Mg II behave in an opposite way in the FWHM-BAI and FWHM-EW parameter spaces.This indicates that the two emission line regions have very different dynamics. We find that,in low redshift sample, the FWHMs of the two lines have a clear and positive correlation,and C Ⅳ and Mg II exhibit the same trend in FWHM-EW parameter space. It means that the two lines are produced in the regions with similar dynamics. Our further analysis shows that, as Lbol/LEdd< 0.1, BAI is almost independent of Lbol/LEdd;while Lbol/LEdd> 0.1,BAI increases strongly with Lbol/LEdd. Similar two-phase behavior is also found in the relation between Lbol/LEddand FWHM(C Ⅳ)/FWHM(Mg II).

关 键 词：活动星系核 发射线 线轮廓 

分 类 号：P157.6[天文地球—天文学]