Changing-look AGN. I. Main sequence transition

This paper is the first in a series of papers that prepare and analyze spectral and other properties for a database of already-discovered changing-look active galactic nuclei...本文为系列研究论文的首篇，该系列论文将针对已发现的变貌活动星系核（changing-look active galactic nuclei）数据库，整理并分析其光谱与其他相关性质……