The Inner Regions of Quasars

最近的观测和理论观点提出了研究类恒星物体(QSO)内部结构的新方法。一个旋转的大质量黑洞似乎是解释射电喷流(光束)和类星体从射电到X射线以外的巨大亮度的最可信的方法。如果吸积的气体有角动量，它很可能会形成一个围绕黑洞自转的圆盘。类星体核心射电辐射相对论光束的新证据支持“统一方案”的想法，该方案将核心主导类星体解释为双叶主导类星体，并允许我们利用射电结构来确定类星体相对于视线的大致方向。最近的观测表明，窄的和宽的发射线区域(NLR和BLR)具有轴对称结构，并与射电轴对齐。如果这一“统一方案”是正确的，新的观测结果表明存在光束光学连续体，这在以核心为主的类星体中很重要，但在以波瓣为主的类星体中并不重要。对连续谱能量分布的新的多频率观测表明，吸积盘的热和其他发射在光学到远紫外光谱中占主导地位，而在近红外区域占主导地位的是热尘埃或自由辐射。这项研究将测试“方案”，并通过设计用于分离IR-UV中的连续谱分量的分光光度和偏振测量，以及通过对仔细定义的类星体样本的发射线光谱和射电、光学和X射线光度的观测，来探索改变类星体内部区域倾角的后果。这些观测结果可以与轴对称宽线区域被圆盘或“喷流”连续体电离的新运动学模型相比较。如果“方案”是不正确的，那么这些观测将测试射电、光学和X射线性质之间的非常强的联系，从而有助于定义未来的假设。

Recent observations and theoretical ideas suggest new ways of investigating the inner structure of quasi-stellar objects (QSOs). A spinning, massive black hole seems the most plausible way to explain radio jets (beams) and, through accretion, the enormous luminosities of quasars from radio to beyond X-rays. If the accreting gas has angular momentum it will probably form a disk about the spin of the hole. New evidence for relativistic beaming of the radio emission from quasars' cores supports the idea of a "Unified Scheme" that explains core-dominated quasars as the double, lobe-dominated quasars seen end-on and allows us to use the radio structure to determine an approximate orientation of a quasar to the line-of-sight. Recent observations suggest an axisymmetric structure for the narrow and broad emission line regions (NLR and BLR) and alignment with the radio axis. If this "Unified Scheme" is correct, new observations imply a beamed optical continuum, important in the core-dominated quasars but insignificant in the lobe-dominated quasars. New multi-frequency observations of continuum energy distributions suggest that thermal and other emission from an accretion disk dominates the optical to far ultraviolet spectrum, while hot dust or free-free emission dominates in the near infrared region. The research will test the "Scheme" and explore the consequences of changing inclination for quasars' inner regions by spectro- photometry and polarimetry designed to separate continuum components in the IR-UV, and by observations of emission line spectra and radio, optical and X-ray luminosities in carefully defined quasar samples. These observations can be compared with new kinematic models for the ionization of an axisymmetric broad line region by a disk or "jet" continuum. If the "Scheme" is incorrect, then these observations will test the very strong link between the radio, optical and X-ray properties, and so help define future hypotheses.