发表机构
Main Astronomical Observatory of the NAS of Ukraine; International Centre for Astronomical, Medical and Ecological Research (ICAMER); Instituto de Astrofísica de Canarias; Departamento de Astrofísica, Universidad de la Laguna（乌克兰国家科学院主天文台; 国际天体医学与生态研究中心; 加那利群岛天体物理研究所; 拉古纳大学天体物理学系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究结合ZTF、WISE和SDSS数据，测量IC~5287和Mrk~845的热尘埃反响延迟，并与光谱预测BLR尺度比较，发现尘埃与BLR半径之比主要受光谱预测尺度影响，强调需区分直接测量与推断半径。
AI 中文摘要
我们研究了孤立Seyfert星系IC~5287和Mrk~845（MCG+09-25-022）中直接测量的热尘埃反响映射尺度与光谱预测的宽线区（BLR）尺度之间的关系，结合了ZTF光学光变曲线、WISE/NEOWISE监测和存档的SDSS光谱。两个星系核均表现出蓝变宽（BWB）光学光变、红变宽（RWB）中红外行为，以及与环核尘埃再处理一致的延迟中红外响应。对于IC~5287，采用通量随机化/随机子集选择不确定性的插值互相关函数分析，得到静止系W1延迟为$106_{-39}^{+24}$天，对应$0.089_{-0.033}^{+0.020}$秒差距。W2的中值响应出现在更长的延迟处，但滞后分布有大量重叠。SDSS分解揭示了强烈的宿主星系稀释和BLR红化，$E(B-V)_{\ m BLR}=0.612_{-0.066}^{+0.067}$星等。作为说明性情景，将相同的色余应用于AGN连续谱，预测的H$\eta$ BLR滞后从约4.8天增加到11.7天，并将尘埃与预测BLR半径之比从约20--25降低到8--10。对于Mrk~845，传递函数建模给出静止系W1延迟为$157_{-8}^{+19}$天，对应$0.132_{-0.007}^{+0.016}$秒差距。其W2响应出现在更长的延迟处，$P(\ au_{\ m W2}>\ au_{\ m W1})=0.963$，支持波长依赖的热尘埃结构。SDSS光谱显示更温和的BLR红化，$E(B-V)_{\ m BLR}=0.197_{-0.039}^{+0.046}$星等。因此，两个星系中相对较大的尘埃与预测BLR半径之比主要反映了光谱预测的BLR尺度。这些结果强调，在解释BLR--尘埃层级时，需要区分直接测量的尘埃反响映射半径与从单历元光谱推断的BLR半径。
英文摘要
We investigate the relation between directly measured hot-dust reverberation scales and spectroscopically predicted broad-line region (BLR) scales in the isolated Seyfert galaxies IC~5287 and Mrk~845 (MCG+09-25-022), combining ZTF optical light curves, WISE/NEOWISE monitoring, and archival SDSS spectroscopy. Both nuclei show BWB optical variability, RWB MIR behaviour, and delayed MIR responses consistent with circumnuclear dust reprocessing. For IC~5287, interpolated cross-correlation function analysis with flux-randomisation/random-subset-selection uncertainties yields a rest-frame W1 delay of $106_{-39}^{+24}$~d, corresponding to $0.089_{-0.033}^{+0.020}$~pc. The median W2 response occurs at a longer delay, but the lag distributions overlap substantially. The SDSS decomposition reveals strong host dilution and BLR reddening, $E(B-V)_{\rm BLR}=0.612_{-0.066}^{+0.067}$~mag. Applying the same colour excess to the AGN continuum as an illustrative scenario increases the predicted H$β$ BLR lag from approximately 4.8 to 11.7~d and reduces the dust-to-predicted-BLR radius ratios from approximately 20--25 to 8--10. For Mrk~845, transfer-function modelling gives a rest-frame W1 delay of $157_{-8}^{+19}$~d, corresponding to $0.132_{-0.007}^{+0.016}$~pc. Its W2 response occurs at a longer delay, with $P(τ_{\rm W2}>τ_{\rm W1})=0.963$, supporting wavelength-dependent hot-dust structure. The SDSS spectrum shows more moderate BLR reddening, $E(B-V)_{\rm BLR}=0.197_{-0.039}^{+0.046}$~mag. The comparatively large dust-to-predicted-BLR radius ratios in both galaxies therefore primarily reflect the spectroscopically predicted BLR scales. These results emphasise the need to distinguish directly measured dust reverberation radii from BLR radii inferred from single-epoch spectroscopy when interpreting the BLR--dust hierarchy.
Comments23 pages, submited to MNRAS journal
