发表机构
South-Western Institute for Astronomy Research, Yunnan University（云南大学西南天文研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过多卫星宽带光谱、时变和偏振观测，揭示黑洞候选体 GS 1354-64 在 2025-2026 爆发中吸积流从硬态到软态的演化，证实盘迁移驱动 QPO 并约束了黑洞自旋与日冕几何。
AI 中文摘要
本文对动力学确认的黑洞候选体 GS 1354-64 在其高度活跃的 2025-2026 爆发期间进行了全面的多卫星分析。利用同步宽带光谱、快速时变和 X 射线偏振测量，我描绘了吸积流的演化和几何结构。在初始康普顿主导的硬态上升阶段，探测到从 0.08 Hz 演化至 1.73 Hz 的强而窄的 Type-C 准周期振荡（QPO），其分数均方根振幅较高（约 8-10%），并与内盘半径（R_in）呈强反相关，与日冕光子指数（Gamma）呈线性相关，支持盘迁移驱动进动频率同时冷却日冕的机制。还观测到一种异常的高度电离（Fe XXVI）赤道盘风，表明在态转变前存在强烈的局部辐射压。在明亮、热主导的软态中，单历元反射建模表明黑洞快速自转（a* ~ 0.94-0.99），倾角 i ~ 45-53 度；跨历元联合光谱建模将参数精化为 i ~ 51 度、a* ~ 0.998，且盘被钉扎在 ISCO 处。QPO 移至更高频率（约 4.7-6.2 Hz）并减弱（RMS ~ 3-6%）。该历元的联合光谱偏振建模揭示了陡峭的、随能量增加的偏振度，排除了球形或灯柱几何结构，支持高度不对称、径向延伸的板状日冕。高 RMS QPO 的抑制与偏振角的严格能量无关性相结合，表明日冕稳定为延伸的对称板状结构，与硬态中膨胀球形日冕的坍缩一致。
英文摘要
A comprehensive multi-satellite analysis of the dynamically confirmed black hole candidate GS 1354-64 during its highly active 2025-2026 outburst is presented. Leveraging simultaneous broadband spectroscopy, fast timing, and X-ray polarimetry, I map the evolution and geometry of the accretion flow. During the initial Compton-dominated hard state rise, strong, narrow Type-C quasi-periodic oscillations (QPOs) evolving from 0.08 Hz to 1.73 Hz with high fractional RMS (~8-10%) are detected, showing a strong anti-correlation with the inner disk radius (R_in) and a linear correlation with the coronal photon index (Gamma), supporting disk migration driving the precessional frequency while cooling the corona. An anomalous, highly ionized (Fe XXVI) equatorial disk wind is also observed, suggesting strong localized radiation pressure prior to the state transition. In the luminous, thermal-dominated soft state, individual-epoch reflection modeling indicated a rapidly spinning black hole (a* ~ 0.94-0.99) at inclination i ~ 45-53 deg; joint spectral modeling across these epochs refines this to i ~ 51 deg and a* ~ 0.998, with the disk pinned to the ISCO. The QPOs shifted to higher frequencies (~4.7-6.2 Hz) and weakened (RMS ~3-6%). Joint spectro-polarimetric modeling of this epoch reveals a steep, energy-increasing polarization degree, ruling out a spherical or lamppost geometry in favor of a highly asymmetric, radially extended slab-like corona. The suppression of the high-RMS QPO, combined with the strict energy-independence of the polarization angle, indicates the corona stabilized into an extended, symmetric slab, consistent with the collapse of the puffed-up spherical corona seen in the hard state.
CommentsAccepted for Publication in the Journal of High Energy Astrophysics (JHEAp)
