Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. XI. Accretion Disk Reverberation Mapping of Mrk 142
Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. XI. Accretion Disk Reverberation Mapping of Mrk 142
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活动星系核中具有高吸积率的超大质量黑洞。
DOI：
10.3847/1538-4357/ab91b5
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发表时间：
2020-06-01
影响因子：
4.9
通讯作者：
Yuan, Ye-Fei
中科院分区：
文献类型：
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作者：
Cackett, Edward M.;Gelbord, Jonathan;Yuan, Ye-Fei
2019年初，我们对高吸积率活动星系核Mrk 142进行了密集的吸积盘混响测绘活动。尼尔·格雷尔斯·斯威夫特天文台对Mrk 142进行了四个月的x射线和六种不同的紫外线/光学滤光器监测。地面光度监测来自拉斯康布雷斯天文台、利物浦望远镜和丹佐瓦达纪念天文台的乌格里兹滤光器，以及云南天文台的V. Mrk 142在整个过程中都是高度可变的，显示出所有波长的相关变异性。我们测量了不同波长光曲线之间的显著时间滞后。在紫外和光学中，我们发现波长相关滞后τ(λ)通常遵循关系τ(λ)∝λ4/3，这与稳态、光学厚、几何薄的吸积盘的T∝R−3/4曲线的预期一致，尽管它们也可以用τ(λ)∝λ2拟合，与薄盘的预期一致。例外的是u和u波段，在那里观察到过量的滞后，就像在其他活动星系核中观察到的那样，并归因于在宽线区域产生的连续辐射。此外，我们进行了通量-通量分析，分离了光谱能量分布的常数和可变分量，发现可变分量的通量依赖关系与几何薄吸积盘期望的fν∝ν1/3谱一致。此外，x射线到紫外线的滞后明显抵消了紫外线/光学趋势的外推，x射线与紫外线的相关性比紫外线与光学的相关性更差。紫外/光学滞后的大小与高度超爱丁顿吸积速率一致。
We performed an intensive accretion disk reverberation mapping campaign on the high accretion rate active galactic nucleus Mrk 142 in early 2019. Mrk 142 was monitored with the Neil Gehrels Swift Observatory for four months in X-rays and six different UV/optical filters. Ground-based photometric monitoring was obtained from the Las Cumbres Observatory, the Liverpool Telescope, and the Dan Zowada Memorial Observatory in ugriz filters, as well as from the Yunnan Astronomical Observatory in V. Mrk 142 was highly variable throughout, displaying correlated variability across all wavelengths. We measure significant time lags between the different wavelength lightcurves. In the UV and optical, we find that the wavelength-dependent lags, τ(λ), generally follow the relation τ(λ) ∝ λ4/3, as expected for the T ∝ R−3/4 profile of a steady-state, optically thick, geometrically thin accretion disk, though they can also be fit by τ(λ) ∝ λ2, as expected for a slim disk. The exceptions are the u and U bands, where an excess lag is observed, as has been observed in other active galactic nuclei and attributed to continuum emission arising in the broad-line region. Furthermore, we perform a flux–flux analysis to separate the constant and variable components of the spectral energy distribution, finding that the flux dependence of the variable component is consistent with the fν ∝ ν1/3 spectrum expected for a geometrically thin accretion disk. Moreover, the X-ray to UV lag is significantly offset from an extrapolation of the UV/optical trend, with the X-rays showing a poorer correlation with the UV than the UV does with the optical. The magnitude of the UV/optical lags is consistent with a highly super-Eddington accretion rate.