衰落AGN候选：AGN历史和流出签名
Fading AGN Candidates: AGN Histories and Outflow Signatures
摘要：
我们考虑了8个衰落活动星系核的能量收支和辐射历史，这些活动星系核是由非常扩展的（>10 kpc）电离云的电离与直接观测到的核光度之间的不匹配确定的。所有这些都显示出在大约50，000年的时间尺度上显着的衰落。我们探索使用最小电离亮度Q来自光电离平衡在H-α在每个投影半径的最亮像素。使用PG类星体的测试，和一个目标与详细的光电离建模，表明我们可以得到有用的历史，个别活动星系核的最小电离光度总是低估，并受到电离物质的精细结构。这些测试表明，对于给定的物体，Q值的上包络的低估大致是恒定的。这些活动星系核显示出快速的下降和静止;共同的特征是在我们看到原子核之前的最后20，000年中快速下降。电子折叠的时间尺度大多是数千年，少数几集短至400年。在很大程度上模糊AGN的限制，我们发现更多的证据褪色，比较下限的重组平衡和最大光度来自红外通量。我们比较这些长期的光变曲线的模拟活动星系核吸积，这些时间跨度上的最强的变化被认为是在模型与强和本地反馈。双子积分场光谱显示出在这些结构中的流出的作用非常有限。虽然环和环的发射是常见的，他们的运动结构显示，一些是在定期旋转。UGC 7342显示出<300 km/s的外流特征，主要与非常扩散的排放有关。只有在茶杯活动星系核中，我们才看到1000 km/s量级的外流信号。这些褪色的活动星系核周围的云主要由潮汐碎片组成，这些碎片被外部照亮，但不被活动星系核外流所取代。（节录）
英文摘要：
We consider energy budgets and radiative history of 8 fading AGN, identified from mismatch between the ionizion of very extended (>10 kpc) ionized clouds and the luminosity of the nucleus viewed directly. All show significant fading on ~50,000-year timescales. We explore the use of minimum ionizing luminosity Q derived from photoionization balance in the brightest pixels in H-alpha at each projected radius. Tests using PG QSOs, and one target with detailed photoionization modeling, suggest that we can derive useful histories of individual AGN; the minimum ionizing luminosity is always an underestimate and subject to fine structure in the ionized material. These tests suggest that the underestimation from the upper envelope of Q values is roughly constant for a given object. These AGN show rapid drops and standstills; the common feature is a rapid drop in the last 20,000 years before our view of the nucleus. E-folding timescales are mostly thousands of years, with a few episodes as short as 400. In the limit of largely obscured AGN, we find additional evidence for fading, comparing lower limits from recombination balance and the maximum luminosities derived from from infrared fluxes. We compare these long-term light curves to simulations of AGN accretion; the strongest variations on these timespans are seen in models with strong and local feedback. Gemini integral-field optical spectroscopy shows a very limited role for outflows in these structures. While rings and loops of emission are common, their kinematic structure shows some to be in regular rotation. UGC 7342 exhibits local signatures of outflows <300 km/s, largely associated with very diffuse emission. Only in the Teacup AGN do we see outflow signatures of order 1000 km/s. Clouds around these fading AGN consist largely of tidal debris being externally illuminated but not displaced by AGN outflows. (Abridged)
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