论文标题
深VLBI观察挑战了居住在Seyfert Galaxy NGC 7674的二元超级黑洞的先前证据
Deep VLBI Observations Challenge Previous Evidence of a Binary Supermassive Black Hole Residing in the Seyfert Galaxy NGC 7674
论文作者
论文摘要
先前的KU波段（15 GHz）成像，并从非常长的基线阵列（VLBA）获得数据，显示了两个紧凑的，子PC的组件，位于Seyfert Galaxy NGC 7674中假定的KPC尺度无线电核心位置，然后据认为这两个没有分解和固定的电台是双重的电台，并认为这两个均匀的无线电均与Dual Dial Procorsys相对均匀。积聚周围的气体并发射无线电相对论喷气机。但是，除了使用从VLBA和欧洲VLBI网络获得的多上述/多频率数据集之外，还利用用于索取二进制SMBH检测的原始VLBA数据集，我们找不到支持二进制SMBH的证据。我们将严格的上限放在任何子PC尺度无线电核心的通量密度上，该核心的磁通量至少比原始的VLBI无线电核检测值低一个数量级，直接挑战了原始的二进制SMBH检测声明。考虑到这一点，我们讨论了我们成像中任何VLBI无线电核心未检测的可能原因，二元SMBH仍居住在NGC 7674中的可能性，以及未来观察结果的前景，进一步了解了这种活跃的银河系核的真实性质。
Previous Ku-band (15 GHz) imaging with data obtained from the Very Long Baseline Array (VLBA) had shown two compact, sub-pc components at the location of a presumed kpc-scale radio core in the Seyfert galaxy NGC 7674. It was then presumed that these two unresolved and compact components were dual radio cores corresponding to two supermassive black holes (SMBHs) accreting surrounding gas and launching radio-bright relativistic jets. However, utilizing the original VLBA dataset used to claim the detection of a binary SMBH, in addition to later multi-epoch/multi-frequency datatsets obtained from both the VLBA and the European VLBI Network, we find no evidence to support the presence of a binary SMBH. We place stringent upper limits to the flux densities of any sub-pc-scale radio cores which are at least an order of magnitude lower than the original VLBI radio-core detections, directly challenging the original binary SMBH detection claim. With this in mind, we discuss the possible reasons for the non-detection of any VLBI radio cores in our imaging, the possibility of a binary SMBH still residing in NGC 7674, and the prospect of future observations shedding further light on the true nature of this active galactic nucleus.
