Missing completely of the CMB quadrupole in WMAP data  

作　　者：LIU Hao LI TiPei 

机构地区：[1]Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences [2]Department of Physics and Center for Astrophysics, Tsinghua University

出　　处：《Chinese Science Bulletin》2013年第11期1243-1249,共7页

基　　金：supported by the National Basic Research Program of China(2009CB824800);the National Natural Science Foundation of China(11033003);the National Natural Science Foundation for Young Scientistsof China (11203024);the Youth Innovation Promotion Association,CAS

摘　　要：In cosmic microwave background (CMB) experiments, foreground-cleaned temperature maps are still contaminated by the residual dipole due to uncertainties of the Doppler dipole direction and microwave radiometer sidelobe. To obtain reliable CMB maps, such contamination has to be carefully removed from observed data. We have previously built a software package for map-making, residual dipole-contamination removal, and power spectrum estimation from the Wilkinson Microwave Anisotropy Probe (WMAP) raw data. This software has now been significantly improved. With the improved software, we obtain a negative result of CMB quadrupole detection with the WMAP raw data, which is 3.2±3.5 K2 from the seven-year WMAP (WMAP7) data. This result is evidently incompatible with ～1000 K2 expected from the standard cosmological model ΛCDM. The completely missing of CMB quadrupole poses a serious challenge to the standard model and sets a strong constraint on possible models of cosmology. Due to the importance of this result for understanding the origin and early evolution of our universe, the software codes we used are opened for public checking.In cosmic microwave background （CMB） experiments, foreground-cleaned temperature maps are still contaminated by the resid- ual dipole due to uncertainties of the Doppler dipole direction and microwave radiometer sidelobe. To obtain reliable CMB maps, such contamination has to be carefully removed from observed data. We have previously built a software package for map-making, residual dipole-contamination removal, and power spectrum estimation from the Wilkinson Microwave Anisotropy Probe （WMAP） raw data. This software has now been significantly improved. With the improved software, we obtain a negative result of CMB quadrupole detection with the WMAP raw data, which is -3.2±3.5 μK2 from the seven-year WMAP （WMAP7） data. This result is evidently incompatible with -1000 μK2 expected from the standard cosmological model ACDM. The completely missing of CMB quadrupole poses a serious challenge to the standard model and sets a strong constraint on possible models of cosmology. Due to the importance of this result for understanding the origin and early evolution of our universe, the software codes we used are opened for public checking.

关 键 词：WMAP 威尔金森微波各向异性探测器 四级 宇宙微波背景辐射 标准宇宙模型 地图制作 原始数据 微波辐射计 

分 类 号：P159[天文地球—天文学] N1[自然科学总论]