Epicyclic oscillations and accretion disk around a special Buchdahl-inspired spacetime
特殊Buchdahl启发时空中的周转圆振荡与吸积盘
In this paper, we consider the Buchdahl-inspired spacetime metric and investigate its aspects using the quasiperiodic oscillations and the accretion disk due to the accreting matter. First, we focus on analyzing the geodesics of particles around the Buchdahl-inspired spacetime, together with the conserved quantities such as specific energy and angular momentum for massive particles orbiting on the innermost stable circular orbits (ISCOs). We show that the effect of the Buchdahl parameter <mml:math><mml:mover><mml:mrow><mml:mi>k</mml:mi></mml:mrow><mml:mrow><mml:mo>~</mml:mo></mml:mrow></mml:mover></mml:math> increases as the radii of the ISCO orbits decrease, resulting in shifting orbits toward the central object compared to the Schwarzschild black hole case. We also consider astrophysical epicyclic oscillations and derive their general expressions using implications of circular motion of massive particles around the Buchdahl-inspired spacetime. Further, we explore the astrophysical implications of observational higher-frequency QPOs of the selected galactic microquasars of X-ray binary systems to obtain the best-fit constraints on the Buchdahl-inspired spacetime parameters. Finally, we consider the accretion disk around the Buchdahl-inspired spacetime using implications of the ISCO parameters that define the accretion disk's inner edge. We explore radiation properties of the accretion disk and redshifted image and intensity of a lensed accretion disk around the Buchdahl-inspired spacetime.
展开 ▾首次把高频QPO共振拟合、Novikov-Thorne薄盘辐射和光线追踪图像联合应用于纯R²引力的特殊Buchdahl时空,给出参数约束并展示其对内吸积盘的显著影响。
该工作延续了纯R²引力中特殊Buchdahl解的系列研究:从Buchdahl早年场方程到Nguyen得到静态球对称解 Nguyen 2023,并由 Azreg-Ainou+ 2023 给出旋转推广与M87*阴影约束,Zhu+ 2024 用S2星与太阳系观测检验该度规。本文在静态近似下进一步把epicyclic QPO共振模型 Stuchlik+ 2016 和Novikov-Thorne薄盘模型 Novikov & Thorne 1973 应用到该时空,发现Buchdahl参数会移动ISCO、增强盘辐射。未来方向需要引入旋转解析解和宇宙学常数贡献,把QPO与吸积盘观测(如X射线双星、EHT图像)联合拟合,以更严格区分Buchdahl时空与Kerr/Schwarzschild假设。
预印本 2025-07-14 · 刊出 2025-07-16 · 收录 2026-08-20