窄线赛佛特I型星系中的宽吸收线外流研究

Narrow-line Seyfert 1 galaxies (NLS1s) and Broad absorption line quasars (BALQSOs) are two special subclasses of active galactic nuclei in the evolution history. They separately represent the quick growth stage and the outflow stage of the central black hole. Evidence has been mounting that NLS1s and BALQSOs share many similar observational properties. However, there has been no systematic study to date the BAL outflow in NLS1s. In this work, we propose to explore the candidates of NLS1s and BALQSOs using the newly released SDSS-III/BOSS spectrum database, construct the BAL-NLS1 sample. With the multi-epoch optical photometric/radio data, the follow-up observations of high-resolution imaging, photometry, optical and near-IR spectroscopy with ground-based facilities, we will systematic study the spectral and multi-band properties of BAL-NLS1s, the photometric variability of optical and radio bands, the variability of broad absorption troughs, the host galaxies and galaxy environment. We also try to explore the high-redshift NLS1s with the widths of Mg II broad emission lines and identify some candidates with their follow-up near-IR spectra. Compare with the low-redshift BAL-NLS1s, we will check the properties of high-redshift objects and the potential evolution of BAL-NLS1s. Our aim is that we will understand the evolution of the black hole, the property and mechanism of outflow, and the outflow feedback to impact galaxy formation and evolution from the study of the BAL outflow in NLS1s.

窄线赛佛特I型星系（NLS1s）和宽吸收线类星体（BALQSOs）分别代表星系活动的两个关键阶段，即中心黑洞演化早期的快速增长阶段和外流阶段。此前对NLS1s和BALQSOs的研究结果显示二者表现出众多相似的观测性质，但迄今尚未对NLS1s中的BAL外流进行系统研究。本项目将利用最新的SDSS-III/BOSS 巡天光谱数据，构建 BAL-NLS1 样本。结合现有多次光学测光和射电巡天数据，国内外地基望远镜获得部分源的成像、测光和光谱观测，首次系统地开展BAL-NLS1的光谱及多波段性质、测光和BAL光变、寄主星系乃至星系环境等多方面的研究。我们也将尝试通过Mg II宽发射线宽度和后续近红外光谱证认的方法获得高红移NLS1s，研究高红移BAL-NLS1性质及可能存在的红移演化。目的从 NLS1的BAL外流入手，深化对黑洞演化、外流的性质及机制、和外流对星系的影响等几方面的认识。

宽吸收线（BAL）外流是产生于AGN核区、携带巨大的能量和动量高速向外的物质流，是黑洞增长对星系演化反馈物理过程的重要候选者。具有低质量高活动性黑洞的AGN，典型如NLS1，被认为对应于黑洞剧烈增长的特殊时期，这一时期的黑洞吸积、外流性质、及对星系演化受到广泛关注，也是本项目的重点研究目标。项目执行期间针对这些高活动性、强外流类星体开展系统性研究，构建目标样本，并对典型个源开展多波段光谱/偏振等后续观测及详细研究，在外流相关的多个领域开展研究并取得如下进展。1)在AGN不同尺度（宽发射线区、尘埃环、星系尺度）上对外流气体定位，表明在NLS1等高活动性AGN中外流广泛存在于不同空间尺度上；2）发现外流气体与尘埃环碰撞产生激波的证据，表明外流可能是宽线区与尘埃环密切关联的桥梁，在AGN结构演化中的作用尤为关键；3）BAL-NLS1的寄主星系具有丰富的多样性，部分NLS1同样遵循M-σ关系，部分则可能具有剧烈的恒星形成活动，BAL类星体中的遮蔽效应为研究其寄主星系提供了极大便利；4）在外流研究工作中，发展出蓝移发射/吸收线联合诊断、多谱线联合诊断、特殊吸收线的独特运用等多种研究手段，诊断研究外流等类星体周围气体性质，是研究外流反馈机制的高效工具。