Reverberation Mapping of IC 4329A
Reverberation Mapping of IC 4329A
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DOI：
10.3847/1538-4357/acab62
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发表时间：
2022-12
期刊：
影响因子：
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通讯作者：
M. Bentz;C. Onken;R. Street;M. Valluri
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文献类型：
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作者：
M. Bentz;C. Onken;R. Street;M. Valluri
我们展示了边缘螺旋 IC 4329A 中的宽线活动星系核 (AGN) 的新混响映射活动的结果。使用 V 波段光度测定法监测光学连续谱，并使用中等分辨率光谱仪监测宽发射线通量变化，从而可以测量 Hβ、Hγ 和 He ii λ4686 的发射线光曲线。我们发现 Hβ 的时间延迟为 16.3−2.3+2.6 天，Hγ 的时间延迟为 16.0−2.6+4.8 天，He ii 的未解决时间延迟为 -0.6−3.9+3.9 天。在对 5100 Å 处的~2.4 mag 的本征消光进行校正后，Hβ 的时间延迟与 AGN 光度和宽线区域半径之间关系的预测值一致。将测量到的 Hβ 时间延迟与宽发射线宽度和采用的值 <f> = 4.8 相结合，我们发现中心超大质量黑洞质量为 MBH=6.8−1.1+1.2×107 M ⊙ 。速度分辨时间延迟是在宽 Hβ 发射线轮廓上测量的，并且可能与“M”状形状一致。 Hβ 的完整混响响应建模只能对某些参数提供适度的约束，但确实与黑洞质量和平均时间延迟表现出一致。这些模型还表明，活动星系核结构与边缘星系盘有很大的偏差。这与活动星系核统一模型的预期一致，在该模型中，预计只有在相对正面倾斜的活动星系核中才能看到宽发射线。
We present the results of a new reverberation mapping campaign for the broad-line active galactic nucleus (AGN) in the edge-on spiral IC 4329A. Monitoring of the optical continuum with V-band photometry and broad emission-line flux variability with moderate-resolution spectroscopy allowed emission-line light curves to be measured for Hβ, Hγ, and He ii λ4686. We find a time delay of 16.3−2.3+2.6 days for Hβ, a similar time delay of 16.0−2.6+4.8 days for Hγ, and an unresolved time delay of −0.6−3.9+3.9 days for He ii. The time delay for Hβ is consistent with the predicted value from the relationship between AGN luminosity and broad-line region radius, after correction for the ∼2.4 mag of intrinsic extinction at 5100 Å. Combining the measured time delay for Hβ with the broad emission-line width and an adopted value of 〈f〉 = 4.8, we find a central supermassive black hole mass of MBH=6.8−1.1+1.2×107 M ⊙. Velocity-resolved time delays were measured across the broad Hβ emission-line profile and may be consistent with an “M”-like shape. Modeling of the full reverberation response of Hβ was able to provide only modest constraints on some parameters, but does exhibit agreement with the black hole mass and average time delay. The models also suggest that the AGN structure is misaligned by a large amount from the edge-on galaxy disk. This is consistent with expectations from the unified model of AGNs, in which broad emission lines are expected to be visible only for AGNs that are viewed at relatively face-on inclinations.