论文标题
更换外观AGN- I.在主要序列上跟踪过渡
Changing-Look AGNs -- I. Tracking the transition on the main sequence of quasars
论文作者
论文摘要
本文是一系列准备和分析光谱和其他特性的第一个，用于已经发现的更换活性银河核（CL AGN）的数据库。在这里，我们专注于从文献中收集的93个Cl AGN样品中的频谱拟合和分析，其中现有SDSS/BOSS/EBOSS光谱法在任何时期中均未完全消失。此外，我们从所有可用的SDSS数据发行中收集了较旧/较新的时期，以使数据库更完整。我们使用pyqsofit并对所有SDSS光谱进行均匀的光谱分解，并按照时间顺序为每个时期列出AGN连续性和发射线的性能。这进一步使我们可以将样本中的源分为\ textit {turn-on}或\ textit {throw}，然后随后检查了此类阶段的重复出现。然后，我们估计黑洞质量（m $ _ {\ rm bh} $）和Eddington Ratio（l $ _ {\ rm bol} $/l $ _ {\ rm edd} $每个源每个源的每个源中所需的参数可用且充分估计的每个源。我们意识到源在m $ _ {\ rm bh} $中的移动，而l $ _ {\ rm bol} $/l $ _ {\ rm edd} $ plane允许我们检查源基本属性的系统更改。然后，我们沿特征向量1（EV1）模式的光平面跟踪它们的过渡，并将其分类的来源分类，该来源要么保持在同一人群（A或B）内（A或B），要么将人口间运动作为光谱时期的函数。我们还测试了我们的Cl AGN样品子集的Balmer降低（H $α$/h $β$）作为时间和AGN光度的函数。
This paper is the first in a series of preparing and analyzing spectral and other properties for a database of already discovered Changing-Look active galactic nuclei (CL AGNs). Here, we focus on the spectral fitting and analysis of broad emission lines in a sample of 93 CL AGNs collected from the literature with existing SDSS/BOSS/eBOSS spectroscopy where the H$β$ emission line profile does not completely disappear in any epochs. Additionally, we have gathered older/newer spectral epochs from all the available SDSS data releases to make the database more complete. We use PyQSOFit and perform a homogeneous spectral decomposition of all of our SDSS spectra and tabulate the AGN continuum and emission line properties per epoch per source, chronologically. This further allows us to categorize the sources in our sample as \textit{Turn-On} or \textit{Turn-Off} and subsequently check for repeated occurrences of such phases. We then estimate the black hole mass (M$_{\rm BH}$) and the Eddington ratio (L$_{\rm bol}$/L$_{\rm Edd}$) per epoch per source where the required parameters are available and well-estimated. We realize the movement of the source in the M$_{\rm BH}$ versus L$_{\rm bol}$/L$_{\rm Edd}$ plane allowing us to check for systematic changes in the source's fundamental properties. We then track their transition along the optical plane of the Eigenvector 1 (EV1) schema and categorize sources that either stay within the same Population (A or B) or make an inter-population movement as a function of spectral epoch. We also test the Balmer decrement (H$α$/H$β$) of a subset of our sample of CL AGNs as a function of time and AGN luminosity.
