标题： 射电识别的超大质量黑洞双星候选体中的相对论喷流和风 显示英文标题

标题： Relativistic Jets and Winds in Radio-Identified Supermassive Black Hole Binary Candidates

摘要： 超大质量黑洞双星系统（SMBHBs）被认为会发出最近发现的nHz引力波背景；然而，到目前为止，还没有任何一个单独的nHz源被确认。 在欧文斯谷射电天文台进行的长期射电监测已经发现了两个潜在的SMBHB候选体：blazars PKS 2131-021和PKS J0805-0111。 这些源在电磁谱上表现出周期性的流量密度变化，表明存在一个良好的时钟。 为了解释这种辐射，我们提出了一种可推广的喷流模型，其中一种轻微相对论性风形成了向外移动的螺旋通道，超相对论性喷流沿此通道传播。 从喷流中观测到的流量变化主要是由于像差效应。 较低频率的辐射出现在更大的半径处，因此其变化相应地被延迟，如观察到的那样。 我们的模型再现了这两个源的主要可观测特征，并且可以在发现其他源时应用。 我们对射电偏振、直接成像和发射线变化进行了预测，这些可以利用未来的观测进行测试。 我们的结果激发了对喷流SMBHB系统的未来数值模拟，并对blazar喷流的供能、结构和演化具有重要意义。 显示英文摘要

摘要： Supermassive black hole binary systems (SMBHBs) are thought to emit the recently discovered nHz gravitational wave background; however, not a single individual nHz source has been confirmed to date. Long-term radio-monitoring at the Owens Valley Radio Observatory has revealed two potential SMBHB candidates: blazars PKS 2131-021 and PKS J0805-0111. These sources show periodic flux density variations across the electromagnetic spectrum, signaling the presence of a good clock. To explain the emission, we propose a generalizable jet model, where a mildly relativistic wind creates an outward-moving helical channel, along which the ultra-relativistic jet propagates. The observed flux variation from the jet is mostly due to aberration. The emission at lower frequency arises at larger radius and its variation is consequently delayed, as observed. Our model reproduces the main observable features of both sources and can be applied to other sources as they are discovered. We make predictions for radio polarization, direct imaging, and emission line variation, which can be tested with forthcoming observations. Our results motivate future numerical simulations of jetted SMBHB systems and have implications for the fueling, structure, and evolution of blazar jets.