作为线强度映射信号的干扰谱线
Interlopers as Signal in Line Intensity Mapping
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中文总结 AI 辅助
研究线强度映射中干扰谱线的处理，将其处理公式化为费舍尔决策问题，通过该方法在相关预测中，Ω_m h^2和BAO距离测量对校准误差较稳健，干扰谱线不仅是污染物，还是宇宙学信号模型校准部分。
中文摘要 AI 辅助
线强度映射测量未解析星系中原子和分子线的组合发射，提供了一种绘制巨大体积宇宙结构的方法。然而，单个观测频率包含来自不同红移的多条谱线的发射。这些干扰谱线通常在宇宙学推断之前被去除。我们表明这种去除并不总是最优的。一旦模型中包含可能的发射线及其红移，干扰谱线就成为其他时期大尺度结构的额外示踪剂，并投影到目标线的坐标系中。我们将干扰谱线处理公式化为一个费舍尔决策问题，要求在选定的容差以下提高精度和参数偏差。在SPHEREx对Hα与[O III]、Hβ和[O II]干扰谱线的预测中，以及在FYST对[C II]与CO干扰谱线的预测中，Ω_m h^2和重子声学振荡（BAO）距离测量对天体物理校准误差相对稳健，而聚类幅度σ_8和暗能量参数w_0和w_a对采用的线模型和先验更敏感。BAO距离测量给出了一个简单的物理图景：对干扰谱线进行建模将两个观测波段变成了一个跨越0.7≤z≤5.8的横向BAO距离阶梯。因此，干扰谱线不仅是要去除的污染物，而且是未来LIM调查宇宙学信号模型的一个经过校准的组成部分。
英文摘要
Line intensity mapping measures the combined emission of atomic and molecular lines from unresolved galaxies, offering a way to map cosmic structure across enormous volumes. A single observed frequency, however, contains emission from several spectral lines at different redshifts. These interlopers are usually removed before cosmological inference. We show that this removal is not always optimal. Once the possible emitting lines and their redshifts are included in the model, interlopers become additional tracers of large-scale structure at other epochs, projected into the coordinate system of the target line. We formulate interloper treatment as a Fisher decision problem, requiring both improved precision and parameter bias below a chosen tolerance. In SPHEREx forecasts for H$α$ with [O III], H$β$, and [O II] interlopers, and in FYST forecasts for [C II] with CO interlopers, $Ω_m h^2$ and baryon acoustic oscillation (BAO) distance measurements are comparatively robust to astrophysical calibration errors, whereas the clustering amplitude $σ_8$ and the dark energy parameters $w_0$ and $w_a$ are more sensitive to the adopted line model and priors. The BAO distance measurement gives a simple physical picture: modeling interlopers turns two observed bands into a transverse BAO distance ladder over $0.7\lesssim z\lesssim5.8$. Interlopers are therefore not only contaminants to remove, but a calibrated component of the cosmological signal model for future LIM surveys.
