论文标题
丽莎频段中双白色矮人的质量和特殊加速度之间的变性
Degeneracy between mass and peculiar acceleration for the double white dwarfs in the LISA band
论文作者
论文摘要
质量和距离是重力波（GW）天文学中测量的基本数量。但是，最近的研究表明，由于GW来源的加速，测量可能会偏差。在这里，我们开发了一种分析方法来量化第三纪在双白色矮人（DWD）上引起的偏差，因为DWDS是Milli-Hertz频段中最常见的GW来源。 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 ${\cal M}(1+Γ)^{3/5}$, where ${\cal M}$ is the real chirp mass of the DWD and $Γ$ is a dimensionless factor proportional to the peculiar acceleration.基于我们的分析方法，我们通过激光干涉仪空间天线（LISA）对DWD进行模拟观察。我们发现，在$ 9 \％的情况下，由于第三纪的存在$（5-30）\％$，因此测得的CHIRP质量有偏见。在大约十二个DWD中发现了更极端的病例，它们可能被错误分类为双中性星星，二进制黑洞，经历传质的DWD，甚至是含有较低质量间隙物体和原始黑洞的二进制文件。质量的偏见还会影响距离的测量，导致在以$ 1 $ kpc的地震距离内看似过度密度的DWD，以及$ 100 $ kpc的密度。我们的结果强调了对GW来源的天体物理环境进行建模以检索其正确的物理参数的必要性。
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 ${\cal M}(1+Γ)^{3/5}$, where ${\cal M}$ is the real chirp mass of the DWD and $Γ$ 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.
