  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 uK^2 from the seven-year WMAP (WMAP7) data. This result is
evidently incompatible with ~1000 uK^2 expected from the standard cosmological
model LCDM. 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.
