论文标题
丽莎频带中气盘的中间质量比的演变
Evolution of gas disc-embedded intermediate mass ratio inspirals in the LISA band
论文作者
论文摘要
在即将到来的空间干涉仪LISA的潜在Millihz引力波（GW）中，有极端或中等质量的比率Inspirals（EMRI/IMRIS）。这些事件涉及质量范围$ 10^5 m _ {\ odot} \ Lessim m \ Lessim 10^7 m _ {\ odot} $的质量范围$ 10^5 m _ {\ odot} \ lyssim m _ {\ odot} $的合并。预计E/IMRI的子集将发生在活性银河核（AGN）的积聚盘中，该圆盘由圆盘施加的扭矩可能会干扰灵感并引起GW波形的相移。在这里，我们使用二维流体动力学模拟与移动网状代码迪斯科舞厅一起进行了系统的椎间盘研究。我们在灵感的BH上测量扭矩，并计算相应的波形偏差，这是二进制质量比$ q \ equiv m_2/m_1 $的函数，光盘粘度（$α$）和气体温度（或等效的MACH数； $ \ $ \ MATHCAL {MATCAL {M} $）。我们发现气体扭矩的绝对值在先前确定的行星迁移扭矩的数量级内，但是它们的精确值和符号在非琐事取决于这些参数的组合。 LISA可以检测到气体印记的嵌入在AGN盘中的二进制物，其表面密度高于$σ_0\ ge10^{4-6} \ rm \，g cm^{ - 2} $，取决于$ q $，$α$和$α$ and $ \ mathcal {m {m} $。在粘度较高的光盘中，偏差最为明显，对于在LISA最敏感的频率下检测到的E/IMRI。较冷的碟片中的扭矩显着依赖于GW驱动的灵感速率以及灵感后期的强烈波动。我们的结果进一步表明，丽莎可能能够对AGN圆盘参数和椎间盘相互作用的物理构成约束。
Among the potential milliHz gravitational wave (GW) sources for the upcoming space-based interferometer LISA are extreme- or intermediate-mass ratio inspirals (EMRI/IMRIs). These events involve the coalescence of supermassive black holes in the mass range $10^5 M_{\odot} \lesssim M \lesssim 10^7 M_{\odot}$ with companion BHs of much lower masses. A subset of E/IMRIs are expected to occur in the accretion discs of active galactic nuclei (AGN), where torques exerted by the disc can interfere with the inspiral and cause a phase shift in the GW waveform. Here we use a suite of two-dimensional hydrodynamical simulations with the moving-mesh code DISCO to present a systematic study of disc torques. We measure torques on an inspiraling BH and compute the corresponding waveform deviations as a function of the binary mass ratio $q\equiv M_2/M_1$, the disc viscosity ($α$), and gas temperature (or equivalently Mach number; $\mathcal{M}$). We find that the absolute value of the gas torques is within an order of magnitude of previously determined planetary migration torques, but their precise value and sign depends non-trivially on the combination of these parameters. The gas imprint is detectable by LISA for binaries embedded in AGN discs with surface densities above $Σ_0\ge10^{4-6} \rm \, g cm^{-2}$, depending on $q$, $α$ and $\mathcal{M}$. Deviations are most pronounced in discs with higher viscosities, and for E/IMRIs detected at frequencies where LISA is most sensitive. Torques in colder discs exhibit a noticeable dependence on the GW-driven inspiral rate as well as strong fluctuations at late stages of the inspiral. Our results further suggest that LISA may be able to place constraints on AGN disc parameters and the physics of disc-satellite interaction.
