论文标题
逼真的前景和仪器模型对21厘米电离实验时期的影响
The Impact of Realistic Foreground and Instrument Models on 21cm Epoch of Reionization Experiments
论文作者
论文摘要
21-CM干涉实验区分重离子（EOR）信号模型的能力的预测通常受数据模型的简单性的限制，这些模型的前景信号和仪器的特征通常被简化或忽略了。要朝着更现实的场景迈进，我们探索了更现实的前景和仪器模型的效果，以将21c的远程驱动器应用于21c的众多群体，并探讨了这些功能。我们使用\ textsc {21cmfast}的高度优化版本，集成到\ textsc {21cmmc}中，以生成亮度温度波动的贝叶斯参数估计的灯光。我们包括一个统计点源前景模型和一个基于在观察时间缩放的Murchison广场阵列（MWA）的仪器模型，具有与未来的平方公里阵列（SKA）相似的有效灵敏度。我们还扩展了当前的似然处方，以说明光束卷积和前景的存在，二维功率谱（PS）以及PS模式的相关性。 We use frequency bands between 150 and 180 MHz to constrain the ionizing efficiency ($ζ$), the minimum virial temperature of halos ($T_{\mathrm{vir}}$), the soft X-ray emissivity per unit Star Formation Rate (SFR) ($L_X/SFR$ ), and the X-ray energy threshold ($E_0$).我们发现，由于未计入EOR信号，前景和热噪声之间的交叉功率，逼真的前景和仪器组件包含偏向参数约束。这导致估计$ζ$的估计值高达$5σ$，但估计为$ t_ {vir} $，l $ _x $/sfr和e $ _0 $仍然不受影响，都在$1σ$之内。
Predictions for the ability of 21-cm interferometric experiments to discriminate Epoch of Reionization (EoR) signal models are typically limited by the simplicity of data models, whereby foreground signals and characteristics of the instrument are often simplified or neglected.To move towards more realistic scenarios, we explore the effects of applying more realistic foreground and instrument models to the 21cm signal, and the ability to estimate astrophysical parameters with these additional complexities. We use a highly-optimized version of \textsc{21cmFAST}, integrated into \textsc{21cmMC}, to generate lightcones of the brightness temperature fluctuation for Bayesian parameter estimation. We include a statistical point-source foreground model and an instrument model based on the Murchison Widefield Array (MWA) scaled in observation time to have an effective sensitivity similar to the future Square Kilometre Array (SKA). We also extend the current likelihood prescription to account for the presence of beam convolution and foregrounds, the 2-Dimensional Power Spectrum (PS), and the correlation of PS modes. We use frequency bands between 150 and 180 MHz to constrain the ionizing efficiency ($ζ$), the minimum virial temperature of halos ($T_{\mathrm{vir}}$), the soft X-ray emissivity per unit Star Formation Rate (SFR) ($L_X/SFR$ ), and the X-ray energy threshold ($E_0$). We find that the inclusion of realistic foregrounds and instrumental components biases the parameter constraints due to unaccounted for cross-power between the EoR signal, foregrounds and thermal noise. This causes estimates of $ζ$ to be biased by up to $5σ$ but the estimates of $T_{vir}$, L$_X$/SFR and E$_0$ remain unaffected and are all within $1σ$.
