标题： LISA频段中双白矮星质量与特殊加速度之间的退化 显示英文标题

标题： Degeneracy between mass and peculiar acceleration for the double white dwarfs in the LISA band

摘要： 质量与距离是引力波（GW）天文学中测量的基本量。 然而，最近的研究表明，由于引力波源的加速度，测量可能会出现偏差。 在这里，我们开发了一种分析方法来量化由第三天体对双白矮星（DWD）引起的这种偏差，因为DWDs是毫赫兹频段中最常见的引力波源。 我们表明，在较大的参数空间中，质量与特殊加速度是简并的，因此从波形中我们只能恢复出一个质量${\cal M}(1+\Gamma)^{3/5}$，其中${\cal M}$是DWD的真实啁啾质量，$\Gamma$是一个与特殊加速度成比例的无量纲因子。 基于我们的分析方法，我们通过激光干涉空间天线（LISA）对DWDs进行了模拟观测。 我们发现，在大约$9\%$的情况下，由于第三天体的存在，测量的啁啾质量会受到$(5-30)\%$的偏差。 在大约十几个DWDs中发现了更加极端的情况，它们可能被误认为是双中子星、双黑洞、正在进行质量转移的DWD，甚至是包含低质量间隙天体和原初黑洞的双星系统。 质量偏差也会影响距离的测量，导致在日心距离为$1$光年以内以及超过$100$光年的区域内，DWDs似乎出现过度密集的现象。 我们的结果突显了建模引力波源天体物理环境的必要性，以正确恢复其物理参数。 显示英文摘要

摘要： Mass and distance are fundamental quantities to measure in gravitational-wave (GW) astronomy. However, recent studies suggest that the measurement may be biased due to the acceleration of GW source. Here we develop an analytical method to quantify such a bias induced by a tertiary on a double white dwarf (DWD), since DWDs are the most common GW sources in the milli-Hertz band. We show that in a large parameter space the mass is degenerate with the peculiar acceleration, so that from the waveform we can only retrieve a mass of ${\cal M}(1+\Gamma)^{3/5}$, where ${\cal M}$ is the real chirp mass of the DWD and $\Gamma$ is a dimensionless factor proportional to the peculiar acceleration. Based on our analytical method, we conduct mock observation of DWDs by the Laser Interferometer Space Antenna (LISA). We find that in about $9\%$ of the cases the measured chirp mass is biased due to the presence of a tertiary by $(5-30)\%$. Even more extreme cases are found in about a dozen DWDs and they may be misclassified as double neutron stars, binary black holes, DWDs undergoing mass transfer, or even binaries containing lower-mass-gap objects and primordial black holes. The bias in mass also affects the measurement of distance, resulting in a seemingly over-density of DWDs within a heliocentric distance of $1$ kpc as well as beyond $100$ kpc. Our result highlights the necessity of modeling the astrophysical environments of GW sources to retrieve their correct physical parameters.