论文标题
最高红移21厘米信号的前景的光学深度
The Optical Depth of Foregrounds for the Highest Redshift 21 cm Signals
论文作者
论文摘要
前景发射使得在任何频率下都难以检测高降低的宇宙学21 cm信号。但是，在低频率下，前景可能会在光学上变厚，这将完全无法看到后面21厘米的信号。为了找出21厘米信号的最高红移可能在光学上厚的区域，我们使用LWA1和Haslam 408 MHz图的测量值使用两个组分的光谱模型，并计算频率依赖的前景光学深度深度在天空中。当前数据的局限性使我们无法以高统计意义得出任何有力的结论，但是有暗示的证据（$ \sim1σ$），对于最高的红移21 cm信号，多达25％的天空可能会被遮盖。
Foreground emission makes it difficult to detect the highly-redshifted cosmological 21 cm signal at any frequency. However, at low frequencies foregrounds are likely to become optically thick, which would make it completely impossible to see a 21 cm signal behind them. To find out which regions of the sky might be optically thick for the highest redshifts of the 21 cm signal, we fit the measurements from LWA1 and the Haslam 408 MHz map with a two-component spectral model and calculate the frequency-dependent foreground optical depth point-by-point across the sky. Limitations of the current data prevent us from making any strong conclusions at high statistical significance, but there is suggestive evidence ($\sim1σ$) that as much as 25% of the sky could be obscured for the highest redshift 21 cm signals.
