AI 中文总结
研究利用中性氢强度映射与星系巡天交叉相关性揭示暗能量特性，通过模拟未来低红移氢原子观测和窄带光学巡天，获得交叉功率谱并进行贝叶斯分析推断宇宙学参数，为21厘米强度映射的宇宙学研究提供重要方法。
AI 中文摘要
中性氢原子超精细结构产生的红移21厘米线是宇宙三维演化的有力追踪器，其广泛时空覆盖对理解暗物质和暗能量复杂本质至关重要。但因存在亮几个数量级的射电前景污染物，直接探测21厘米信号极具挑战，减轻前景污染成为检测该信号的必要任务，且其有望与暗物质主导的大尺度结构相关。未来中性氢强度映射与星系巡天的交叉相关性不仅能确认21厘米信号检测，还可作为21厘米宇宙学的补充探测手段。为满足宇宙学研究精度要求，利用数值模拟研究估计交叉相关性的复杂特征很重要。本文模拟未来低红移氢原子观测和窄带光学巡天，获得减轻前景和偏差的氢原子-星系交叉功率谱，并进行贝叶斯分析以推断动态暗能量模型的宇宙学参数。本文所开发方法对21厘米强度映射的宇宙学研究很重要。
英文摘要
The redshifted 21 cm line from the hyperfine structure of neutral hydrogen atoms is a promising tracer for the three-dimensional evolution of our universe. Its broad spatial and temporal coverage is crucial for understanding the complex nature of dark matter and dark energy. However, it is very challenging to directly detect the 21 cm signal due to the existence of radio foreground contaminants that are orders of magnitude brighter. Therefore, mitigating the foreground contamination becomes an indispensable task for detecting the 21 cm signal, which is also expected to be correlated with the dark-matter-dominated large-scale structure. The cross-correlations between the neutral hydrogen intensity mapping and galaxy surveys in the future can not only confirm a detection of the 21 cm signal but can also be a complementary probe for 21 cm cosmology. To meet the precision requirements for cosmological studies, it is important to investigate the complex features of the estimated cross-correlations using numerical simulations. In this work, we simulate the low-redshift HI observations and narrow-band optical surveys in the future and obtain the foreground- and bias-mitigated HI-galaxy cross-power spectra, with which we perform a Bayesian analysis to infer cosmological parameters of dynamical dark energy model. The method developed in this work will be important for cosmological studies with the 21 cm intensity mapping.
Comments11 pages, 5 figures
