Synergies between radio, optical and microwave observations at high redshift
Synergies between radio, optical and microwave observations at high redshift
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DOI：
10.1088/1475-7516/2019/07/023
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发表时间：
2018-10
影响因子：
6.4
通讯作者：
Shi-Fan Chen;E. Castorina;M. White;A. Slosar
中科院分区：
文献类型：
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作者：
Shi-Fan Chen;E. Castorina;M. White;A. Slosar
我们研究了三种有前途的方法之间的协同作用，以测量22和遭受即使是光谱调查的闯入者的问题。21 cm信号的强度映射可以以精确的保真度覆盖大体积，但受限于前景清洁的信息损失和缺乏平均信号的知识。宇宙微波背景（CMB）透镜理论上是非常干净的，但最终测量的只是密度的投影变化。我们发现，光和无线电之间的互相关可以显着改善增长率的测量。结合这些与CMB提供了一个很有前途的途径，以检测修改后的重力在高红移，特别是通过独立探测外尔和牛顿的潜力，并加强控制的系统。我们发现，交叉相关的阶段{\sc ii} 21厘米的调查与DESI类星体与一个合理的亮度温度之前，可以使测量的增长率fσ8在低于3%和低于8%的水平，在z = 3，4，代表一个因素的4和8的改善，从DESI类星体单独获得的限制。类似地，将21 cm数据与未来的LBG测量进行交叉关联，使mUV<24.5超过1000平方度，将使fσ8测量在z = 3时接近1%，在z = 4时接近3%，并将z = 5时的类似约束提高接近3倍至低于10%的精度。将上述与来自第四阶段CMB测量的CMB透镜和LSST数据相结合，可以额外地将引力滑移γ参数约束到这些红移的类似精度，使我们能够在大尺度上测试广义相对论的预测。
We study synergies between three promising methods to measure 22 and suffer from interloper problems even for spectroscopic surveys. Intensity mapping of the 21-cm signal can cover large volumes with exquisite fidelity, but is limited both by loss of information to foreground cleaning and by lack of knowledge of the mean signal. Cosmic microwave background (CMB) lensing is theoretically very clean, but ultimately measures just the projected variations in density. We find that cross-correlation between optical and radio can significantly improve the measurement of growth rate. Combining these with the CMB provides a promising avenue to detecting modified gravity at high redshifts, in particular by independently probing the Weyl and Newtonian potentials and by strengthening control of systematics. We find that cross-correlating a Stage {\sc ii} 21-cm survey with DESI quasars with a reasonable brightness temperature prior could enable measurements of the growth rate fσ8 at sub 3% and sub 8% levels at z = 3, 4, representing a factor of 4 and 8 improvement over constraints obtainable from DESI quasars alone. Similarly, cross-correlating 21-cm data with a futuristic LBG survey to mUV<24.5 over 1000 square degrees will make possible fσ8 measurements at close to 1% at z = 3 and 3% at z = 4, and improve similar constraints at z = 5 by close to a factor of 3 to sub-10% precision. Combining the above with CMB lensing from a Stage 4 CMB survey and LSST data can additionally constrain the gravitational slip γ parameter to similar precision at these redshifts, enabling us to test the predictions of general relativity at large scales.