标题： 红移 CII 观测宇宙学巡天的光谱混淆问题 显示英文标题

标题： Spectral Confusion for Cosmological Surveys of Redshifted CII Observations

摘要： 远红外冷却线是在形成恒星的星系光谱中普遍存在的重要特征。 红移精细结构线的调查提供了一种有前景的新工具，可以用来研究包括再电离时代和恒星形成高峰时期的结构形成和星系演化。 与中性氢调查不同，在中性氢调查中21厘米线是唯一的亮线，红移精细结构线的调查由于线宽增加、不同线的光谱重叠以及源的拥挤而产生混淆。 我们利用模拟来研究由此产生的光谱混淆，并推导出观察参数以最小化笔形束调查中红移远红外线发射的这些影响。 我们生成了星系中17条最亮的远红外线的模拟光谱，覆盖从150到1300微米波长范围（对应于红移0 < z < 7），并开发了一个简单的迭代算法，成功地识别出了158微米的[CII]线以及其他线。 尽管[CII]线是星际介质的主要冷却剂，但假设视线中最亮的线总是[CII]线的假设在加入其他线后对模拟光谱来说是一种较差的近似。 盲目的线识别需要检测来自同一宿主星系的更暗的伴线，从而推动了调查灵敏度的要求。 观测需要适度的光谱分辨率700 < R < 4000，角分辨率为20弧秒到10弧分之间，足够窄以最小化混淆，同时又足够宽以包含统计上有意义数量的源。 显示英文摘要

摘要： Far infrared cooling lines are ubiquitous features in the spectra of star forming galaxies. Surveys of redshifted fine-structure lines provide a promising new tool to study structure formation and galactic evolution at redshifts including the epoch of reionization as well as the peak of star formation. Unlike neutral hydrogen surveys, where the 21 cm line is the only bright line, surveys of red-shifted fine-structure lines suffer from confusion generated by line broadening, spectral overlap of different lines, and the crowding of sources with redshift. We use simulations to investigate the resulting spectral confusion and derive observing parameters to minimize these effects in pencil-beam surveys of red-shifted far-IR line emission. We generate simulated spectra of the 17 brightest far-IR lines in galaxies, covering the 150 to 1300 micron wavelength region corresponding to redshifts 0 < z < 7, and develop a simple iterative algorithm that successfully identifies the 158 micron [CII] line and other lines. Although the [CII] line is a principal coolant for the interstellar medium, the assumption that the brightest observed lines in a given line of sight are always [CII] lines is a poor approximation to the simulated spectra once other lines are included. Blind line identification requires detection of fainter companion lines from the same host galaxies, driving survey sensitivity requirements. The observations require moderate spectral resolution 700 < R < 4000 with angular resolution between 20 arcsec and 10 armin, sufficiently narrow to minimize confusion yet sufficiently large to include a statistically meaningful number of sources.