AI 中文总结
对1ES 1927+654进行多波段监测，用多台设备观测其光谱演化。发现喷流形成时出现软X射线发射线，还检测到Fe K发射特征，揭示电离吸收体变化及吸积和外流过程转变，表明喷流形成时相关区域稳定。
AI 中文摘要
我们展示了在射电喷流（2022年5月 - 2025年8月）开始和演化期间对可变视类活动星系核1ES 1927+654进行的全面多波段监测结果。利用多台设备观测来表征源的光谱演化。发现喷流形成时出现软X射线发射线，检测到Fe K发射特征，揭示电离吸收体变化及吸积和外流过程转变，还表明喷流形成时相关区域稳定，宽线区域情况也得以说明。
英文摘要
We present results from a comprehensive multi-wavelength monitoring campaign of the changing-look active galactic nucleus 1ES 1927+654 during the onset and evolution of a relativistic radio jet $\sim$(May 2022 - August 2025), using observations from XMM-Newton, Swift, TNG, ZTF, VLA, and VLBA. The soft X-ray emission lines at $\sim 0.56$ keV and $\sim 1$ keV have appeared with variable strength and width during the formation of the nascent jet. We note that the $\sim 1$ keV feature has been persisting since the post-2017 flare phase. We also report the detection of a broad ($\sim 800$ eV) FeK emission feature at $(6-7)$ keV in the $\sim 70$ ks stacked EPIC-pn spectra, marking the first such detection, which historically was lacking in this source. The joint spectral fitting of XMM-Newton EPIC-pn and RGS data reveals the presence of ionized absorbers in 2022 ($\log{ξ\mathrm{/erg\ cm\ s^{-1}}}\sim 1.5\pm 0.3$, $\mathrm{N_H} \sim 2.5\pm 0.9\times 10^{20} \mathrm{cm^{-2}}$), but weaker than that detected during the high accretion state in 2018 (Eddington ratio, $λ_{\rm Edd}>1$). The absorption features further weakened in 2023-2025 and were marginally detectable ($\mathrm{N_H} \le 10^{20}\mathrm{cm^{-2}}$). The entire scenario is suggestive of a real-time transition of the accretion flow (from $λ_{\rm Edd}>1$ to $λ_{\rm Edd}\sim 0.3$) during which the winds become weaker and the jet starts to form and evolve. Furthermore, both the soft X-ray $(0.3-2)$ keV and 5 GHz radio fluxes, which increased by factors of $\sim 10$ and $\sim 60$, respectively, since 2022, have recently plateaued at elevated levels, indicating a stabilized accretion disk, corona, and jet configuration.
