论文标题
旋转二进制中子星的合并期间F模型的激发
Excitation of f-modes during mergers of spinning binary neutron star
论文作者
论文摘要
潮汐效应对涉及中子星(NSS)的二进制阶层的最后阶段的重力波(GWS)具有重要的烙印。当NS振荡与轨道运动共鸣时,动态潮汐可能很重要。了解此过程对于准确地对这些二进制文件进行建模GW排放非常重要,以及从GW数据中提取NS信息。在本文中,我们进行了一项系统的研究,以对合并二进制的NSS旋转NS的基本模式进行潮汐激发,重点介绍了NS旋转与轨道角动量抗对数时的情况 - 潮汐共振很可能发生。我们首先将NS振荡扩展到恒星的特征模式中,然后获得控制潮汐耦合轨道模式演化的哈密顿量。接下来,我们找到一个新的近似值,可以导致潮汐激发的分析表达式以高度准确性,并且在二进制进化的所有制度中都是有效的:绝热,谐振和谐振。使用映射轨道的方法,我们获得了轨道演化和GW发射的半分析近似;他们与数值结果的协议使我们对我们对系统动态的理解有信心。特别是,我们恢复了平均的呼声后进化,这与绕轨道和角动量的变化以及由潮汐运动驱动的瞬时扰动不同,与谐振点粒子轨道不同。最后,我们使用Fisher基质技术来研究动力潮对参数估计的影响。我们发现,动态潮汐可能会提供一个额外的通道来研究NSS的物理学。本文介绍的方法是通用的,不仅限于F模式。它也可以应用于其他类型的潮汐。
Tidal effects have important imprints on gravitational waves (GWs) emitted during the final stage of the coalescence of binaries that involve neutron stars (NSs). Dynamical tides can be significant when NS oscillations become resonant with orbital motion; understanding this process is important for accurately modeling GW emission from these binaries, and for extracting NS information from GW data. In this paper, we carry out a systematic study on the tidal excitation of fundamental modes of spinning NSs in coalescencing binaries, focusing on the case when the NS spin is anti-aligned with the orbital angular momentum-where the tidal resonance is most likely to take place. We first expand NS oscillations into stellar eigen-modes, and then obtain a Hamiltonian that governs the tidally coupled orbit-mode evolution. We next find a new approximation that can lead to analytic expressions of tidal excitations to a high accuracy, and are valid in all regimes of the binary evolution: adiabatic, resonant, and post-resonance. Using the method of osculating orbits, we obtain semi-analytic approximations to the orbital evolution and GW emission; their agreements with numerical results give us confidence in on our understanding of the system's dynamics. In particular, we recover both the averaged post-resonance evolution, which differs from the pre-resonance point-particle orbit by shifts in orbital energy and angular momentum, as well as instantaneous perturbations driven by the tidal motion. Finally, we use the Fisher matrix technique to study the effect of dynamical tides on parameter estimation. We find that the dynamical tides may potentially provide an additional channel to study the physics of NSs. The method presented in this paper is generic and not restricted to f mode; it can also be applied to other types of tide.