TY - JOUR

T1 - Realistic simulations of the Galactic polarized foreground

T2 - consequences for 21-cm reionization detection experiments

AU - Jelic, Vibor

AU - Zaroubi, Saleem

AU - Labropoulos, Panagiotis

AU - Bernardi, Gianni

AU - de Bruyn, A. G.

AU - Koopmans, Leon V. E.

PY - 2010/12/21

Y1 - 2010/12/21

N2 - 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.

AB - 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.

KW - polarization

KW - radiation mechanisms: non-thermal

KW - instrumentation: interferometers

KW - cosmology: observations

KW - radio continuum: general

KW - PROBE WMAP OBSERVATIONS

KW - INTERGALACTIC MEDIUM

KW - SYNCHROTRON EMISSION

KW - RADIO-EMISSION

KW - SPECTRAL INDEX

KW - IONIZED-GAS

KW - GAMMA-RAYS

KW - MILKY-WAY

KW - 150 MHZ

KW - EPOCH

UR - http://adsabs.harvard.edu/abs/2010MNRAS.409.1647J

U2 - 10.1111/j.1365-2966.2010.17407.x

DO - 10.1111/j.1365-2966.2010.17407.x

M3 - Article

VL - 409

SP - 1647

EP - 1659

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 4

ER -