发表机构
MIT; University of Maryland, College Park; NASA/GSFC; CRESST II, NASA Goddard Space Flight Center; Center for Astrophysics, Harvard & Smithsonian; X-ray Astrophysics Laboratory, NASA Goddard Space Flight Center; Ohio State University; California Institute of Technology; Villanova University（麻省理工学院; 马里兰大学帕克分校; 美国国家航空航天局戈达德太空飞行中心; NASA戈达德太空飞行中心CRESST II项目; 哈佛-史密森天体物理中心; NASA戈达德太空飞行中心X射线天体物理学实验室; 俄亥俄州立大学; 加州理工学院; 维拉诺瓦大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过联合建模Swift/XRT和NuSTAR光谱，分析GRS 1716-249和GRS 1739-278中间态，发现自旋推断受模型与数据约束影响，需宽带覆盖和物理自洽模型。
AI 中文摘要
对恒星质量黑洞自旋的测量可在强引力条件下探测吸积过程，并约束黑洞的形成与演化。中间态中，热盘、冕和反射发射均有显著贡献，是自旋测量中特别复杂的环境，也适用于探测光谱建模的系统性效应。我们利用 GRS 1716-249 和 GRS 1739-278 的成对、非同时的 Swift/XRT 和 NuSTAR 观测来研究这些效应。我们使用 kerrbb 和 relxillCp 联合建模光谱，链接或分别变化其自旋参数，并通过马尔可夫链蒙特卡洛分析探索参数空间。在所采用的模型内，GRS 1716 强烈倾向于高自旋，而 GRS 1739 的数据允许高自旋和低自旋解，且拟合统计量几乎相同。参数步进实验表明，参数间的协调变化可使实质不同的物理配置产生几乎无法区分的光谱。对于这些数据集和所采用的模型，能带测试显示 Fe 能带对推断自旋提供最强的直接灵敏度，而康普顿隆起有助于约束反射参数，软 X 射线能带则表征底层连续谱。当盘连续谱和反射成分均得到充分约束时，其相关的自旋参数可在联合模型内支持一个共同解。在约束较弱的情况下，模型允许统计上可比较的解跨越几乎整个自旋范围。稳健的联合连续谱和反射自旋推断需要宽带覆盖、独立的双星约束、物理自洽的模型以及对参数空间的彻底探索。
英文摘要
Measurements of stellar-mass black hole spin probe accretion under strong gravity and constrain black hole formation and evolution. Intermediate states, in which thermal disk, coronal, and reflection emission all contribute significantly, are particularly complex environments for spin measurements and useful for probing spectral-modeling systematics. We investigate these effects using paired, non-simultaneous Swift/XRT and NuSTAR observations of GRS 1716-249 and GRS 1739-278. We jointly model the spectra with kerrbb and relxillCp, linking or separately varying their spin parameters, and explore the parameter space with a Markov Chain Monte Carlo analysis. Within the adopted model, GRS 1716 strongly favors a high spin, whereas the GRS 1739 data allow high- and low-spin solutions with nearly identical fit statistics. Parameter-stepping experiments show that coordinated changes among parameters allow substantially different physical configurations to produce nearly indistinguishable spectra. For these datasets and within the adopted model, energy-band tests show that the Fe band provides the strongest direct sensitivity to the inferred spin, while the Compton hump helps constrain reflection parameters and the soft X-ray band characterizes the underlying continuum. When both the disk continuum and reflection components are adequately constrained, their associated spin parameters can favor a common solution within the joint model. With weaker constraints, the model permits statistically comparable solutions spanning nearly the full range of spins. Robust joint continuum and reflection spin inference requires broadband coverage, independent binary constraints, physically self-consistent models, and thorough exploration of parameter space.
Comments12 pages plus appendices. 8 figures, 5 tables. To be submitted to the Open Journal of Astrophysics
