Realistic simulations of the Galactic polarized foreground: consequences for 21-cm reionization detection experiments

Vibor Jelic*, Saleem Zaroubi, Panagiotis Labropoulos, Gianni Bernardi, A. G. de Bruyn, Leon V. E. Koopmans

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Abstract

Experiments designed to measure the redshifted 21-cm line from the epoch of reionization (EoR) are challenged by strong astrophysical foreground contamination, ionospheric distortions, complex instrumental response and other different types of noise (e.g. radio frequency interference). The astrophysical foregrounds are dominated by diffuse synchrotron emission from our Galaxy. Here we present a simulation of the Galactic emission used as a foreground module for the Low Frequency Array (LOFAR)-EoR key science project end-to-end simulations. The simulation produces total and polarized intensity over 10 degrees x 10 degrees maps of the Galactic synchrotron and free-free emission, including all observed characteristics of the emission: spatial fluctuations of amplitude and spectral index of the synchrotron emission, together with Faraday rotation effects. The importance of these simulations arises from the fact that the Galactic polarized emission could behave in a manner similar to the EoR signal along the frequency direction. As a consequence, an improper instrumental calibration will give rise to leakages of the polarized to the total signal and mask the desired EoR signal. In this paper, we address this for the first time through realistic simulations.

Original languageEnglish
Pages (from-to)1647-1659
Number of pages13
JournalMonthly Notices of the Royal Astronomical Society
Volume409
Issue number4
DOIs
Publication statusPublished - 21-Dec-2010

Keywords

  • polarization
  • radiation mechanisms: non-thermal
  • instrumentation: interferometers
  • cosmology: observations
  • radio continuum: general
  • PROBE WMAP OBSERVATIONS
  • INTERGALACTIC MEDIUM
  • SYNCHROTRON EMISSION
  • RADIO-EMISSION
  • SPECTRAL INDEX
  • IONIZED-GAS
  • GAMMA-RAYS
  • MILKY-WAY
  • 150 MHZ
  • EPOCH

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