The Effects of Polarized Foregrounds on 21cm Epoch of Reionization Power
  Spectrum Measurements
  Experiments aimed at detecting highly-redshifted 21 centimeter emission from
the Epoch of Reionization (EoR) are plagued by the contamination of foreground
emission. A potentially important source of contaminating foregrounds may be
Faraday-rotated, polarized emission, which leaks into the estimate of the
intrinsically unpolarized EoR signal. While these foregrounds' intrinsic
polarization may not be problematic, the spectral structure introduced by the
Faraday rotation could be. To better understand and characterize these effects,
we present a simulation of the polarized sky between 120 and 180 MHz. We
compute a single visibility, and estimate the three-dimensional power spectrum
from that visibility using the delay spectrum approach presented in Parsons et
al. (2012b) . Using the Donald C. Backer Precision Array to Probe the Epoch of
Reionization (PAPER) as an example instrument, we show the expected leakage
into the unpolarized power spectrum to be several orders of magnitude above the
expected 21cm EoR signal.
