发表机构
Montana State University（蒙大拿州立大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出一种快速正向模型，将银河系引力波光度密度映射到LISA年调制前景，并预测一年观测可约束盘尺度宽度和高度分别达8%和12%。
AI 中文摘要
激光干涉空间天线（LISA）的观测将包含来自银河系的时变、循环平稳的混淆噪声，这自然需要使用时频分析方法来处理。我们提出了一种快速的正向模型，该模型将参数化的银河系引力波光度密度映射到完整的时间延迟干涉测量通道集合中年调制、未解析的混淆前景上。视线光度积分在HEALPix网格上评估并分解为球谐函数，而探测器响应则解析分解，与银河系模型无关，因此一个新的银河系模型仅需一次地图评估、变换和收缩。我们计算了超出标准低频极限的调制协方差，将LISA响应展开到有限臂长修正的二阶，以及不等臂修正的一阶。这些效应在3和5 mHz频率下分别使归一化调制曲线改变高达约0.23%和0.64%，在自通道和交叉通道中分别使归一化调制曲线改变约0.074%和0.71%。利用快速正向模型和概念性的盘状-核球银河系模型，我们从时间相关的通道协方差构建了Fisher矩阵，并预测一年的观测将盘尺度宽度和尺度高度相对于到银河系中心的距离的约束分别限制在8%和12%的水平，而强相关的核球分数和核球半径则各自无法被单独约束。
英文摘要
Observations by the Laser Interferometer Space Antenna (LISA) will contain time-varying, cyclostationary confusion noise from the Galaxy, which is naturally handled using time-frequency analysis methods. We present a fast, forward model that maps the parameterized Galactic gravitational-wave luminosity density onto the annually modulated, unresolved confusion foreground in the complete set of time-delay interferometry channels. The line-of-sight luminosity integral is evaluated on a HEALPix grid and decomposed into spherical harmonics, while the detector response is decomposed analytically, independent of the Galaxy model, such that a new Galactic model costs a single map evaluation, transformation, and contraction. We compute the modulated covariance beyond the standard low-frequency limit, expanding the LISA response to second order in finite armlength corrections, and to first order in the unequal-arm corrections. These effects change the normalized modulation curves by up to $\sim\!0.23\%$ and $0.64\%$ for finite armlength corrections at $3$ and $5$ mHz respectively, and by $\sim\!0.074\%$ and $0.71\%$ for unequal-arm corrections in the self and cross channels respectively. Using the fast, forward model and a notional disk-and-bulge Galaxy model, we construct a Fisher matrix from the time-dependent channel covariance and forecast that one year of observation constrains the disk scale width and scale height relative to the distance to the Galactic center at the $8\%$ and $12\%$ levels respectively, and leaves the strongly correlated bulge fraction and bulge radius individually unconstrained.
Comments23 pages, 18 figures
