通过X射线食变运动学解析武仙座X-1的铁K复合体：吸积盘与电离风
Kinematically Resolving the Fe K Complex in Her X-1: The Accretion Disk and Ionized Wind Across X-ray Eclipses
中文总结 AI 辅助
本研究利用XRISM/Resolve光谱仪观测武仙座X-1的三次X射线食变，解析铁K复合体，揭示中性铁发射源于中子星附近、电离线源于延展区域，确定盘风参数与外流率。
中文摘要 AI 辅助
我们展示了XRISM/Resolve光谱仪对2024年9月观测到的武仙座X-1三次X射线食变的观测结果，解析了其铁K复合体在入食、食甚和出食阶段的形态。Resolve的5 eV高能量分辨率使我们能够分解并探测到铁K复合体的所有主要成分：中性铁荧光（Fe Kα和Kβ）、高度电离的发射线（Fe XXV Heα和Fe XXVI Lyα）。中性Fe Kα发射在食甚期间未被显著探测到，表明其起源于中子星附近的致密区域。在入食和出食阶段，经系统速度和中子星轨道运动校正后，谱线中心分别呈现约200 km s⁻¹的红移和蓝移。这种残余位移对应于特征半径r_disk ~ 6.6×10⁶ km处的开普勒旋转，暗示其与外吸积盘相关。相比之下，高度电离的Fe XXV Heα和Fe XXVI Lyα线在食变期间仍可见，表明其起源于延展区域。光致电离建模（SPEX pion模型）得出log₁₀(ξ/erg cm s⁻¹) ~ 3.4，N_H ~ 3.1×10²² cm⁻²，与武仙座X-1的电离盘风一致。流量比诊断约束了团块状盘风的几何内边界为R_in = 3⁺⁵₋₂×10¹⁰ cm（1σ），与康普顿加热的热风一致。推断的质量外流率为Ṁ_out ≈ 3.2×10⁻⁹ M☉ yr⁻¹（为供给质量的一半），与食变外盘风的吸收线测量结果一致。
英文摘要
We present XRISM/Resolve spectroscopy of Her X-1 across three X-ray eclipses observed in September 2024, resolving its iron K complex through the ingress, mid-eclipse, and egress phases. The 5 eV high energy resolution of Resolve enabled us to disentangle and detect all primary components of the iron K complex: neutral iron fluorescence (Fe K$α$ and K$β$), highly ionized emission lines (Fe XXV He$α$ and Fe XXVI Ly$α$). The neutral Fe K$α$ emission is not significantly detected during mid-eclipse, indicating a compact origin near the neutron star. At ingress and egress, the line centroid exhibits red- and blue-shifts of $\sim 200$ km s$^{-1}$ after correcting for the systemic velocity and the neutron star's orbital motion. This residual shift corresponds to Keplerian rotation at a characteristic radius of $r_{\rm disk} \sim 6.6\times10^{6}$ km, suggesting an association with the outer accretion disk. In contrast, the highly ionized Fe XXV He$α$ and Fe XXVI Ly$α$ lines remain visible during eclipses, indicating an extended origin. Photoionization modeling (SPEX pion model) yields $\log_{10}(ξ/{\rm erg\,cm\,s^{-1}}) \sim 3.4$ and $N_{\rm H} \sim 3.1\times10^{22}$ cm$^{-2}$ consistent with the ionized disk wind of Her X-1. Flux-ratio diagnostics constrain the geometric inner boundary of the clumpy disk wind to $R_{\rm in} = 3^{+5}_{-2} \times 10^{10}$ cm ($1σ$), consistent with the Compton-heated thermal winds. The inferred mass outflow rate is $\dot{M}_{\rm out} \approx 3.2 \times 10^{-9}\,M_{\odot}$ yr$^{-1}$ (half the supplied mass), consistent with absorption line measurements of the disk wind obtained out of eclipse.
