BAL and non-BAL quasars: continuum, emission, and absorption properties establish a common parent sample
BAL and non-BAL quasars: continuum, emission, and absorption properties establish a common parent sample
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DOI：
10.1093/mnras/staa130
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发表时间：
2019-12
影响因子：
4.8
通讯作者：
A. Rankine;P. Hewett;M. Banerji;G. Richards
中科院分区：
文献类型：
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作者：
A. Rankine;P. Hewett;M. Banerji;G. Richards
以Sloan数字巡天数据第14版中的144000个类星体为研究对象，研究了红移1.6≤$z$≤3.5、光度45.3 erg s−1 < log10(Lbol) < 48.2 erg s−1的高电离宽吸收线（BAL）和非BAL类星体的吸出和发射特性。研究的关键是基于平均场独立分量分析的连续体和发射在线重建方案，该方案允许直接比较非BAL和BAL类星体的C iv λ1550发射线的运动学特性。因此，可以对这两个种群进行iv辐射蓝移和等效宽度（EW）测量。发射线特性和BAL波谷特性的比较表明，发射和吸收特性之间存在很强的系统相关性。定量流出指标对物理性质的依赖，如类星体亮度和相对于Eddington亮度的亮度，也被证明在BAL和非BAL种群中基本相同。在光谱能量分布最硬的类星体中，存在较强的He i λ1640发射，较大的C iv λ1550发射，且没有可测量的蓝移。在C iv发射蓝移相对于EW空间的其余部分，BAL和非BAL类星体在所有位置都存在；对于每一个BAL类星体，都有可能识别出具有相同发射线流出特性和SED硬度的非BAL类星体。BAL和非BAL类星体的共定位作为发射线流出和物理性质的函数是我们研究的关键结果，表明（高电离）BALs和非BALs代表了同一类星体群的不同观点。
Using a sample of ≃144 000 quasars from the Sloan Digital Sky Survey Data Release 14, we investigate the outflow properties, evident in both absorption and emission, of high-ionization broad absorption line (BAL) and non-BAL quasars with redshifts 1.6 ≲ $z$ ≤ 3.5 and luminosities 45.3 erg s−1 < log10(Lbol) < 48.2 erg s−1. Key to the investigation is a continuum and emission-line reconstruction scheme, based on mean-field independent component analysis, that allows the kinematic properties of the C iv λ1550 emission line to be compared directly for both non-BAL and BAL quasars. C iv emission blueshift and equivalent width (EW) measurements are thus available for both populations. Comparisons of the emission-line and BAL trough properties reveal strong systematic correlations between the emission and absorption properties. The dependence of quantitative outflow indicators on physical properties such as quasar luminosity and luminosity relative to Eddington luminosity is also shown to be essentially identical for the BAL and non-BAL populations. There is an absence of BALs in quasars with the hardest spectral energy distributions (SEDs), revealed by the presence of strong He ii λ1640 emission, large C iv λ1550 emission EW, and no measurable blueshift. In the remainder of the C iv emission blueshift versus EW space, BAL and non-BAL quasars are present at all locations; for every BAL quasar, it is possible to identify non-BAL quasars with the same emission-line outflow properties and SED hardness. The co-location of BAL and non-BAL quasars as a function of emission-line outflow and physical properties is the key result of our investigation, demonstrating that (high-ionization) BALs and non-BALs represent different views of the same underlying quasar population.