高红移射电噪类星体的光变研究

High-redshift radio-loud quasars have been rarely discovered to date, among which the intrinsic variability and physics are poorly known. In the end of 2013, we discovered a new radio-loud quasar at z=5.18 using the Lijiang 2.4m Telescope, which may host a supermassive black hole (SMBH, >10^9 solar masses) and emit above Eddington luminosity (bolometric luminosity larger than Eddington limit). Then, it was identified as the third most distant Blazar by X-ray and VLBI follow-ups. Considering variability can be effectively used to explore the physical properties of SMBH and jet, we launched a monitoring campaign for this source and other three sources with similar features, and a bunch of high-quality data with respect to photometry and spectroscopy have been obtained. Combining multi-wavelength data from previous and future observations, this project will reveal variability properties among high-redshift radio-loud quasars in the first time, and hence provide important clues for the study of SMBHs and jets in the early Universe.

高红移射电噪类星体是一类罕见的天体，其光变特征和物理机制还很不清楚。2013年底，我们利用丽江2.4米望远镜发现了一颗红移5.18的射电噪类星体，其很可能拥有超大黑洞质量（大于10^9太阳质量）以及超爱丁顿光度（热光度甚至超过爱丁顿极限）。随后，经过空间X射线卫星和VLBI的后续跟踪观测，进一步表明其为目前所发现的红移第三高的Blazar！考虑到光变监测能够更深入地探索其超大质量黑洞和喷流的物理特性，我们对该源以及其它三个性质接近的射电噪类星体展开了光变监测，目前已经获得了一批长期+短期、测光+光谱的高质量数据。结合现有和将来的多波段数据，本项目有望第一次揭示出高红移射电噪类星体的光变行为和特征，从而为研究早期宇宙的超大质量黑洞和喷流提供重要线索。

高红移射电噪类星体是一类罕见的天体，其发射线/吸收线的光变行为和物理机制还很不清楚。本项目主要对这类天体开展系统性的研究以及对一些个源进行持续的测光和光谱观测。在一个红移较低的比较样本中我们发现：（1）射电噪类星体中吸收线的光变与一些基本物理量如黑洞质量、吸积率等无明显相关性；（2）射电噪类星体所占的比例（～23%）远高于预期的结果（～1%）。另外，在项目期内对个源开展的监测中，我们已经积累了一些光学/红外的观测数据。考虑到静止系和观测系之间相差一个（1+z）因子，继续维持定期的监测将有助于更全面和深入的理解这类天体。