发表机构
Università di Camerino; Al-Farabi Kazakh National University; INAF, Catania Astrophysical Observatory; ICRANet; Kazakh-British Technical University; Eastern Mediterranean University; Khazar University; Fesenkov Astrophysical Institute（卡梅里诺大学; 阿尔法拉比哈萨克国立大学; 国家天体物理研究所，卡塔尼亚天文台; 国际相对论天体物理中心网络; 哈英技术大学; 东地中海大学; 哈萨克斯坦大学; 费森科夫天体物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过分析12个吸积致密天体的QPO数据，利用MCMC模拟约束STVG理论参数，发现轨道动力学仅依赖于两个组合参数，为QPO计时测量设定了模型无关极限。
AI 中文摘要
我们研究了标量-张量-矢量引力（STVG）静态带电解中中性测试粒子的圆形测地线，并利用十二个吸积致密天体的孪生千赫兹准周期振荡（QPO）来约束其参数。从有效势出发，我们得到了比能量、比角动量和开普勒角速度的闭合形式，并由此得到径向和垂直方向的偏心频率。视界、光子球、阴影半径和最内层稳定圆轨道也以闭合形式给出，每个在适当极限下都简化为RN和Schwarzschild值。零测地线通过数值积分显示，增强的耦合拓宽了俘获截面，同时保持了光子球处偏转角对数发散的不变性。在RP模型内，我们对八颗中子星和四个微类星体的QPO对进行了Metropolis-Hastings MCMC模拟，比较了Schwarzschild时空、RN时空、无电荷STVG和完整STVG解。最佳拟合主要出现在中子星样本的带电解中，而所有四个模型对黑洞样本的描述同样好。我们证明轨道动力学仅通过两个组合$\Meff=(1+\alpha)M$和$\Qeff^{2}=(1+\alpha)(\alpha M^{2}+Q^{2})$依赖于质量$M$、耦合$\alpha$和电荷$Q$，这解释了中子星样本中发现的多峰后验分布，并设定了仅凭QPO计时所能测量的模型无关极限。这些约束的天体物理意义，特别是对超过Tolman-Oppenheimer-Volkoff极限的推断质量的启示，被详细讨论。
英文摘要
We study circular geodesics of neutral test particles in the static charged solution of Scalar--Tensor--Vector Gravity (STVG), and we use the twin kilohertz quasiperiodic oscillations (QPOs) of twelve accreting compact objects to bound its parameters. Starting from the effective potential we obtain closed forms for the specific energy, the specific angular momentum and the Keplerian angular velocity, and from these the radial and vertical epicyclic frequencies. The horizon, photon sphere, shadow radius and innermost stable circular orbit are given in closed form as well, and each one reduces to the RN and Schwarzschild value in the appropriate limit. Null geodesics are integrated numerically and show how the enhanced coupling widens the capture cross section while leaving the logarithmic divergence of the deflection angle at the photon sphere intact. Within the RP model we then run Metropolis--Hastings MCMC simulations on the QPO pairs of eight neutron stars and four microquasars, comparing the Schwarzschild spacetime, the RN spacetime, STVG with vanishing charge and the full STVG solution. The best fits are obtained mainly for the charged solutions in the neutron star sample, while all four models describe the black hole sample equally well. We show that the orbital dynamics depends on the mass $M$, the coupling $α$ and the charge $Q$ only through the two combinations $\Meff=(1+α)M$ and $\Qeff^{2}=(1+α)(αM^{2}+Q^{2})$, which accounts for the multimodal posteriors found in the neutron star sample and sets a model-independent limit on what QPO timing alone can measure. The astrophysical implications of these bounds, in particular for inferred masses above the Tolman--Oppenheimer--Volkoff limit, are discussed in detail.
Comments33 pages, 13 figures and 3 tables
