Modeling transient resonances in extreme-mass-ratio inspirals
Modeling transient resonances in extreme-mass-ratio inspirals
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DOI：
10.1103/physrevd.106.104001
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发表时间：
2022-05
影响因子：
5
通讯作者：
Priti Gupta;L. Speri;B. Bonga;A. J. Chua;Takahiro Tanaka
中科院分区：
文献类型：
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作者：
Priti Gupta;L. Speri;B. Bonga;A. J. Chua;Takahiro Tanaka
极端质量比吸气是天基干涉仪（如LISA， TianQin）最令人兴奋和最有前途的目标源之一。对它们发射的引力波的观测将为广义相对论提供严格的检验，并提供有关银河系中心密集环境的丰富信息。为了释放这种潜力，有必要正确表征EMRI信号。然而，共振是发生在EMRI系统中的一种现象，如果没有正确建模，它会影响参数推理，从而影响科学结果。在这里，我们将探讨如何建立共振模型并开发有效的实现。我们之前的工作已经证明，由附近天体物理对象的潮汐场引起的潮汐共振改变了轨道演化，导致在可观测参数空间中显着的减相。在此，我们广泛探索了具有附加共振组合的潮汐摄动器的更通用模型，以研究共振强度与本征轨道和潮汐参数的依赖关系。为了分析共振信号，需要精确的模板来正确地结合潮汐场的影响。通过阶跃函数得到共振的演化，阶跃函数的振幅通过共振跳变的解析插值计算。我们通过比较我们的近似方法和数值演化来对这个过程进行基准测试。我们发现，在参数空间的天文合理范围内，简化后的公式没有引起明显的误差。此外，我们使用Fisher矩阵来研究参数的测量精度和由于建模不准确而导致的系统偏差。自力共振的建模也可以使用本研究中提出的实现来进行，这对于EMRI波形建模至关重要。
Extreme-mass-ratio inspirals are one of the most exciting and promising target sources for space-based interferometers (such as LISA, TianQin). The observation of their emitted gravitational waves will offer stringent tests on general theory of relativity, and provide a wealth of information about the dense environment in galactic centers. To unlock such potential, it is necessary to correctly characterize EMRI signals. However, resonances are a phenomena that occurs in EMRI systems and can impact parameter inference, and therefore the science outcome, if not properly modeled. Here, we explore how to model resonances and develop an efficient implementation. Our previous work has demonstrated that tidal resonances induced by the tidal field of a nearby astrophysical object alters the orbital evolution, leading to a significant dephasing across observable parameter space. Here, we extensively explore a more generic model for the tidal perturber with additional resonance combinations, to study the dependence of resonance strength on the intrinsic orbital and tidal parameters. To analyze the resonant signals, accurate templates that correctly incorporate the effects of the tidal field are required. The evolution through resonances is obtained using a step function, whose amplitude is calculated using an analytic interpolation of the resonance jumps. We benchmark this procedure by comparing our approximate method to a numerical evolution. We find that there is no significant error caused by this simplified prescription, as far as the astronomically reasonable range in the parameter space is concerned. Further, we use Fisher matrices to study both the measurement precision of parameters and the systematic bias due to inaccurate modeling. Modeling of self-force resonances can also be carried out using the implementation presented in this study, which will be crucial for EMRI waveform modeling.