arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1001.0463astro-ph.CO
收藏

均匀QSO样品的研究:QSO和它的宿主星系之间的关系

Study of a homogeneous QSO sample: relations between the QSO and its host galaxy

Y. Letawe, G. Letawe, P. Magain

摘要:

我们分析了从104个类星体的完整样本中随机选取的69个类星体的样本(R<18,0.142 < z < 0.198)。在La Silla使用NTT/SUSI 2通过光学波段的两个滤波器(WB#655和V#812)观察到60个,其余9个来自档案数据库。滤波器V#812包含红移的Hbeta和禁戒的[OIII]发射线,而WB#655覆盖了没有发射线的光谱区域,从而测量了类星体和恒星连续谱。由于MCS反卷积算法,类星体和宿主的贡献被分离,允许宿主的形态分类,以及计算几个参数,如宿主和核的绝对V-星等,宿主和类星体的光度中心之间的距离,以及宿主和核的颜色。我们定义了一个新的不对称系数,独立于任何星系模型,非常适合类星体主机的研究。本研究的主要结果是:(i)类星体主体总数的25%是螺旋体,51%是椭圆体,60%显示出相互作用的迹象;(ii)高度不对称的系统往往具有较高的气体电离水平;(iii)椭圆体主体含有大量的电离气体,有些显示出非核活动。这些结果符合层次模型合并驱动的演化。

英文摘要:

We analyse a sample of 69 QSOs which have been randomly selected in a complete sample of 104 QSOs (R<18, 0.142 < z < 0.198). 60 have been observed with the NTT/SUSI2 at La Silla, through two filters in the optical band (WB#655 and V#812), and the remaining 9 are taken from archive databases. The filter V#812 contains the redshifted Hbeta and forbidden [OIII] emission lines, while WB#655 covers a spectral region devoid of emission lines, thus measuring the QSO and stellar continua. The contributions of the QSO and the host are separated thanks to the MCS deconvolution algorithm, allowing a morphological classification of the host, and the computation of several parameters such as the host and nucleus absolute V-magnitude, distance between the luminosity center of the host and the QSO, and colour of the host and nucleus. We define a new asymmetry coefficient, independent of any galaxy models and well suited for QSO host studies. The main results from this study are: (i) 25% of the total number of QSO hosts are spirals, 51% are ellipticals and 60% show signs of interaction; (ii) Highly asymmetric systems tend to have a higher gas ionization level (iii) Elliptical hosts contain a substantial amount of ionized gas, and some show off-nuclear activity. These results agree with hierarchical models merger driven evolution.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑