发表机构
Physical Research Laboratory; Midnapore City College; IIT Kanpur（物理研究实验室; 金达尔城市学院; 坎普尔印度理工学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究利用多台望远镜观测数据，分析黑洞X射线双星Swift J151857.0-572147的多波段特性，确认其处于软/中间态，符合银河系黑洞X射线双星的射电/X射线相关性，证实其黑洞本质。
AI 中文摘要
我们利用AstroSat、NuSTAR、NICER、Swift和MeerKAT望远镜的观测数据，研究了2024年爆发期间新发现的黑洞X射线双星Swift J151857.0-572147的多波段时变和光谱特性。AstroSat/LAXPC20的功率密度谱显示存在一个约8赫兹的低频准周期振荡（QPO），其品质因数约为2.8。该源的宽频X射线光谱呈现出显著的反射特征，我们通过对这些特征进行建模来限制吸积盘的几何结构和物理性质。光谱分析表明，该源处于软/中间光谱态，其特征是幂律指数较陡，光子指数Γ≈2.6，且吸积盘温度相对较高，约为0.9千电子伏特（keV）。反射建模结果显示，吸积盘的倾角为23°至31°，且吸积盘高度电离，电离度的对数logξ约为3.3至4.0。MeerKAT的监测结果显示，该源的射电辐射存在强烈的变化，且这种变化与硬X射线的演化密切相关，包括在硬态向软态转变期间出现的一次明亮射电耀斑，这一现象支持了吸积流与喷流活动之间存在紧密耦合的观点。利用准同时的AstroSat、Swift/XRT和MeerKAT观测数据，我们研究了射电/X射线相关性，发现Swift J151857.0-572147符合已确立的银河系黑洞X射线双星的L_X-L_R关系。该源在L_X-L_R平面中的位置与银河系黑洞X射线双星的位置一致，进一步证实了其黑洞的本质。
英文摘要
We investigate multiwavelength timing and spectral properties of the newly discovered black hole X-ray binary Swift J151857.0-572147 during its 2024 outburst using observations from AstroSat, NuSTAR, NICER, Swift, and MeerKAT. The AstroSat/LAXPC20 power density spectrum reveals a $\sim$8 Hz low-frequency QPO with a quality factor of $\sim2.8$. The broadband X-ray spectrum of the source exhibits prominent reflection features, which are modeled to constrain the geometry and physical properties of the accretion disk. The spectral analysis indicates that the source was in the soft/intermediate spectral state, characterized by a steep power law with a photon index of $Γ\approx 2.6$ and a relatively high disk temperature of $\sim0.9$ keV. The reflection modeling suggests a disk inclination of $23-31^{\circ}$ and a highly ionized accretion disk with $\logξ\sim 3.3$-4.0. The MeerKAT monitoring revealed a strong radio variability that closely tracked the hard X-ray evolution, including a bright radio flare during the hard-to-soft state transition, supporting close coupling between the accretion flow and jet activity. Using the quasi-simultaneous AstroSat, Swift/XRT and MeerKAT observations, we investigated the radio/X-ray correlation and found that Swift J151857.0-572147 follows the established $L_{\rm X}$-$L_{\rm R}$ relation for Galactic black hole X-ray binaries. Its location in the $L_{\rm X}$-$L_{\rm R}$ plane is consistent with that of Galactic black hole X-ray binaries, further supporting its black hole nature.
CommentsAccepted for publication in ApJ
