Simulation of systematic effects in CMB power spectra

Cosmic microwave background (CMB) polarization measurements can give us extremely valuable information about our universe. Measurements of these faint signals will play a major role in understanding the inflationary epoch and the distribution of matter and the evolution of large scale structure. Measuring the CMB polarization has become one of the major goals of CMB experiments. However, the polarized CMB signal is so small that its measurement requires not only very high instrumental sensitivity, but also exquisite control of systematics.

In collaboration with Greg Tucker's group at Brown University, Ben Wandelt's group at the Institut d'Astrophysique (Paris) and Ted Bunn's group at University of Richmond, we are building a suite of simulation software to simulate CMB interferometric observations and to assess various systematic errors in CMB power spectra estimates by using maximum likelihood method and Gibbs sampling technique.

As this project is making rapid progress, four papers has recently been published in ApJS, and one in MNRAS
  • Bayesian angular power spectrum analysis of interferometric data, arXiv:1109.4640
  • Maximum likelihood analysis of systematic errors in interferometric observations of the cosmic microwave background, arXiv:1209.2676
  • Bayesian Inference of Polarized CMB Power Spectra from Interferometric Data, arXiv:1209.2930
  • Systematic Effects in Interferometric Observations of the CMB Polarization, arXiv:1302.6608
  • Probabilistic image reconstruction for radio interferometers, arXiv:1309.1469

Simulated CMB Stokes maps and visibilities for interferometric observations.

Simulated Stokes visibilities

Recovered CMB Power Spectra

Recovered CMB power spectra

Effects of systematic pointing errors in CMB power spectra

Pointing errors<