论文标题
铅笔梁星系调查和线强度地图的跨相关性：詹姆斯·韦伯太空望远镜的应用
Cross Correlation of Pencil-Beam Galaxy Surveys and Line-Intensity Maps: An Application of the James Webb Space Telescope
论文作者
论文摘要
线强度映射（IM）实验试图用光谱线（例如21cm，co和lyman- $α$（ly $α$））对大规模结构进行统计测量。这些观察结果中的一个挑战是确保天体物理前景（例如21cm测量中的银河同步也发射）得到正确去除。一种有可能减少前景污染的方法是与与IM体积重叠的星系调查相互关联。但是，与IM调查相比，对高红移星系敏感的望远镜通常具有较小的视野（FOV）。因此，跨相关性的星系调查必然由铅笔梁组成，铅笔梁稀疏地填充了IM体积。在本文中，我们开发了形式主义，以预测IM实验与铅笔梁星系调查之间的跨相关性的敏感性。我们发现，铅笔梁的随机分布导致非常相似的总体灵敏度，与在IM调查中间隔间隔的晶格相似，并得出了与Fisher Matrix形式主义一致的随机配置的简单公式。我们探讨了将高红移詹姆斯·韦伯太空望远镜（JWST）和类似于球形的ly $α$ im调查和基于基于氢化氢阵列氢时代（HERA）的21厘米实验组合的实例。我们发现JWST-SPHEREX案例很有希望，导致$ {\ sim} 5 $的总信噪比为100个JWST（$ z = 7 $）。我们发现，由于其漂流策略，HERA不适合这种方法，但是可以在一个领域中集成的类似实验。
Line-intensity mapping (IM) experiments seek to perform statistical measurements of large-scale structure with spectral lines such as 21cm, CO, and Lyman-$α$ (Ly$α$). A challenge in these observations is to ensure that astrophysical foregrounds, such as galactic synchrotron emission in 21cm measurements, are properly removed. One method that has the potential to reduce foreground contamination is to cross correlate with a galaxy survey that overlaps with the IM volume. However, telescopes sensitive to high-redshift galaxies typically have small field of views (FOVs) compared to IM surveys. Thus, a galaxy survey for cross correlation would necessarily consist of pencil beams which sparsely fill the IM volume. In this paper, we develop the formalism to forecast the sensitivity of cross correlations between IM experiments and pencil-beam galaxy surveys. We find that a random distribution of pencil beams leads to very similar overall sensitivity as a lattice spaced across the IM survey and derive a simple formula for random configurations that agrees with the Fisher matrix formalism. We explore examples of combining high-redshift James Webb Space Telescope (JWST) observations with both a SPHEREx-like Ly$α$ IM survey and a 21cm experiment based on the Hydrogen Epoch of Reionization Array (HERA). We find that the JWST-SPHEREx case is promising, leading to a total signal-to-noise of ${\sim}5$ after 100 total hours of JWST (at $z=7$). We find that HERA is not well-suited for this approach owing to its drift-scan strategy, but that a similar experiment that can integrate down on one field could be.
