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arXiv 1602.02765astro-ph.GAastro-ph.COastro-ph.IM
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检验类星体的统一性:在云风中的辐射转移

Testing Quasar Unification: Radiative Transfer in Clumpy Winds

James H. Matthews, Christian Knigge, Knox S. Long, Stuart A. Sim, Nick Higginbottom, Sam W. Mangham

摘要:

各种统一方案解释了复杂的现象,类星体和发光的活动星系核(AGN)的一个简单的图片,涉及一个中心黑洞,吸积盘和相关的流出。在这里,我们继续我们的测试,这种模式的类星体光谱比较合成光谱的双锥盘风模型,产生与我们的国家的最先进的蒙特卡罗辐射转移代码。以前,我们已经表明,我们可以产生类似于观察到的宽吸收线(BAL)类星体的合成光谱,但只有当X射线光度限制在$10^{43}$尔格s $^{-1}$。在这里,我们介绍了一个简单的治疗结块,并发现$\sim0.01$的填充因子缓和的电离状态足以BAL功能形成在休息帧UV在更现实的X射线光度。我们的基准模型显示出与活动星系核X射线特性的良好一致性,风在例如,Ly α和CIV 1550 °。在高倾角,光谱具有突出的LoBAL功能。尽管取得了这些成功,我们不能再现所有的发射线中看到的类星体光谱与正确的等效宽度比,我们发现一个角度依赖的发射线等效宽度,尽管在所观察到的发射线性质的BAL和非BAL类星体的相似之处。总的来说,我们的工作表明,双锥风可以再现统一模型所预期的大部分定性行为,但我们还不能在所有视角下提供与类星体性质的定量匹配。因此,盘风能否成功地统一类星体仍然是一个悬而未决的问题。

英文摘要:

Various unification schemes interpret the complex phenomenology of quasars and luminous active galactic nuclei (AGN) in terms of a simple picture involving a central black hole, an accretion disc and an associated outflow. Here, we continue our tests of this paradigm by comparing quasar spectra to synthetic spectra of biconical disc wind models, produced with our state-of-the-art Monte Carlo radiative transfer code. Previously, we have shown that we could produce synthetic spectra resembling those of observed broad absorption line (BAL) quasars, but only if the X-ray luminosity was limited to $10^{43}$ erg s$^{-1}$. Here, we introduce a simple treatment of clumping, and find that a filling factor of $\sim0.01$ moderates the ionization state sufficiently for BAL features to form in the rest-frame UV at more realistic X-ray luminosities. Our fiducial model shows good agreement with AGN X-ray properties and the wind produces strong line emission in, e.g., Ly α and CIV 1550Å at low inclinations. At high inclinations, the spectra possess prominent LoBAL features. Despite these successes, we cannot reproduce all emission lines seen in quasar spectra with the correct equivalent-width ratios, and we find an angular dependence of emission-line equivalent width despite the similarities in the observed emission line properties of BAL and non-BAL quasars. Overall, our work suggests that biconical winds can reproduce much of the qualitative behaviour expected from a unified model, but we cannot yet provide quantitative matches with quasar properties at all viewing angles. Whether disc winds can successfully unify quasars is therefore still an open question.

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