论文标题
使用ugmrt的z = 1.96-3.58的第一个多速度限制（eor后）21 cm信号
First multi-redshift limits on post-Epoch of Reionization (post-EoR) 21 cm signal from z = 1.96 - 3.58 using uGMRT
论文作者
论文摘要
从重新电位时期（Z <6）中弥漫性HI 21 cm背景辐射中的波动的测量是探测宇宙大规模结构并了解星系演化的有前途的途径。我们使用升级的巨型MeterWave射电望远镜（UGMRT）观察到300-500 MHz的欧洲大区域调查 - 北1（ELAIS-N1）字段，并采用“前景避免”技术来估算RedShift Z = 1.96-3.58的HI 21 cm功率光谱。鉴于数据可能保留在数据中的可能系统学，我们发现球形平均21 cm功率谱的最严格的上限在k〜1.0 mpc $^{ - 1} $是（58.87 mk）$^2 $，（61.49 mk）（61.49 mk）分别为1.96，2.19，2.62和3.58。我们将其用来将中性HI质量密度（Omega_hi）和HI偏差（B_HI）的产物限制为基础的暗物质密度字段，[Omega_hi*b_hi]，分别为0.09,0.11,12,0.12,12,0.24，分别为z = 1.96,2.196,2.196,2.19,2.62,2.62,3.58。据我们所知，这些是在红移范围z = 1.96-3.58处HI 21 cm功率谱的第一个限制，并且将在限制星系形成和进化的模型中发挥重要作用。
Measurement of fluctuations in diffuse HI 21 cm background radiation from the post-reionization epoch (z < 6) is a promising avenue to probe the large-scale structure of the Universe and understand the evolution of galaxies. We observe the European Large-Area ISO Survey-North 1 (ELAIS-N1) field at 300-500 MHz using the upgraded Giant Meterwave Radio Telescope (uGMRT) and employ the 'foreground avoidance' technique to estimate the HI 21 cm power spectrum in the redshift range z = 1.96-3.58. Given the possible systematics that may remain in the data, we find the most stringent upper limits on the spherically averaged 21 cm power spectra at k~1.0 Mpc$^{-1}$ are (58.87 mK)$^2$, (61.49 mK)$^2$, (60.89 mK)$^2$, (105.85 mK)$^2$ at z = 1.96,2.19,2.62 and 3.58, respectively. We use this to constrain the product of neutral HI mass density (Omega_HI) and HI bias (b_HI) to the underlying dark matter density field, [Omega_HI*b_HI], as 0.09,0.11,0.12,0.24 at z=1.96,2.19,2.62,3.58, respectively. To the best of our knowledge these are the first limits on the HI 21 cm power spectra at the redshift range z = 1.96 - 3.58 and would play a significant role to constrain the models of galaxy formation and evolution.
