An Evolutionary Scenario for Blazar Unification
An Evolutionary Scenario for Blazar Unification
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DOI：
10.1086/324134
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发表时间：
2001-06
期刊：
影响因子：
--
通讯作者：
M. Böttcher;C. Dermer
中科院分区：
文献类型：
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作者：
M. Böttcher;C. Dermer
从平谱射电类星体（FSRQs）到低频峰BL Lac天体（LBLs）到高频峰BL Lac天体（HBLs），Blazar子类表现出光谱硬度随着光度降低而增加的序列，这不能仅仅用方向效应来解释。使用的同步加速器，同步加速器自康普顿，康普顿散射的外部辐射耀变体喷气机的分析模型，我们提出了一个进化的情况下，这些耀变体子类的黑洞吸积功率随时间的减少。当环核物质吸积为中心引擎提供燃料时，留下的气体和尘埃就更少了，从而散射吸积盘辐射，并在耀变体光谱中产生外部康普顿散射分量。这种进化趋势产生了FSRQ → LBL → HBL的序列。这种情况也可能联系无线电响亮AGN与超亮红外星系和光学类星体，如果后者构成超大质量黑洞生长的高爱丁顿比时期，正如在一些银河系黑洞候选者中观察到的无线电和软X射线活动之间的关系所表明的那样。
Blazar subclasses ranging from flat-spectrum radio quasars (FSRQs) through low-frequency-peaked BL Lac objects (LBLs) to high-frequency-peaked BL Lac objects (HBLs) exhibit a sequence of increasing spectral hardness with decreasing luminosity that cannot be explained solely by orientation effects. Using an analytic model for the synchrotron, synchrotron self-Compton, and Compton-scattered external radiation from blazar jets, we propose an evolutionary scenario that links these blazar subclasses in terms of a reduction of the black hole accretion power with time. As the circumnuclear material accretes to fuel the central engine, less gas and dust are left to scatter accretion-disk radiation and produce an external Compton-scattered component in blazar spectra. This evolutionary trend produces the sequence FSRQ → LBL → HBL. Such a scenario may also link radio-loud AGNs with ultraluminous infrared galaxies and optical quasars, if the latter constitute the high-Eddington-ratio epoch of supermassive black hole growth, as suggested by the observed anticorrelation between radio and soft X-ray activity in some Galactic black hole candidates.