用空间分辨LBT光谱重新审视双AGN候选者--溢出光污染的影响
Revisiting dual AGN candidates with spatially resolved LBT spectroscopy -- The impact of spillover light contamination
摘要：
超大质量黑洞（SMBH）的合并是我们对星系演化的分层图像的直接结果。在星系合并过程中，很难跟踪SMBH的合并过程，因为SMBH自然难以观察。我们想确认和确认的存在下，两个独立的活动星系核（AGN）的几个千秒差距，在7个强相互作用的星系先前选择从斯隆数字巡天（SDSS）作为塞弗特-塞弗特对的基础上发射线比诊断。本文利用大双筒望远镜（LBT）上的MODS观测到的光学狭缝光谱，推断出了光发射谱线的详细空间分布，以及它们相对于宿主星系的谱线比和活动星系核的特征，从而量化了光束拖尾和大光纤孔径对SDSS观测到的光谱的影响。我们发现，最多有两个七个目标实际上保留了塞弗特-塞弗特双活动星系核，而其他可能更有可能由退休星系中的后AGB恒星或通过基于空间分辨光学线诊断的ISM中的冲击提供动力。这种差异的主要原因是由次级SDSS纤维中的初级源的通量溢出引起的偏差，其在<3”的分离处可以超过一个数量级。以前报道的极低的X射线-[ \ion{O}{iii} ]光度比可以用这种错误的分类来解释，因为活动星系核的主要成分被严重遮蔽。我们还发现，与年轻的恒星年龄的核主机的主要活动星系核。仅从基于光纤的光谱学中选择的近对偶活动星系核的研究可能会在样品选择和结果解释中产生严重的偏差。理想的情况是，未来应使用空间分辨光谱技术，结合多波长跟踪观测，对这种紧凑型系统进行观测。
英文摘要：
The merging of supermassive black holes (SMBHs) is a direct consequence of our hierarchical picture of galaxy evolution. It is difficult to track the merging process of SMBHs during mergers of galaxies as SMBHs are naturally difficult to observe. We want to characterise and confirm the presence of two independent active galactic nuclei (AGN) separated by a few kiloparsec in seven strongly interacting galaxies previously selected from the Sloan Digital Sky Survey (SDSS) as Seyfert-Seyfert pairs based on emission-line ratio diagnostics. Optical slit spectra taken with MODS at the Large Binocular Telescope (LBT) are presented to infer the detailed spatial distribution of optical emission lines, and their line ratios and AGN signatures with respect to the host galaxies, thereby quantifying the impact of beam smearing and large fibre apertures on the spectra captured by the SDSS. We find that at most two of the seven targets actually retain a Seyfert-Seyfert dual AGN, whereas the others may be more likely powered by post-AGB stars in retired galaxies or through shocks in the ISM based on spatially resolved optical line diagnostics. The major cause of this discrepancy is a bias caused by the spillover of flux from the primary source in the secondary SDSS fibre which can be more than an order of magnitude at <3" separations. Previously reported extremely low X-ray-to-[\ion{O}{iii}] luminosity ratios may be explained by this misclassification, as can heavily obscured AGN for the primaries. We also find that the nuclei with younger stellar ages host the primary AGN. Studies of close dual AGN selected solely from fibre-based spectroscopy can create severe biases in the sample selection and interpretation of the results. Spatially resolved spectroscopy should ideally be used in the future to characterise such compact systems together with multi-wavelength follow-up observations.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
