Tuesday, January 15, 2013

1301.3126 (Bryna J. Hazelton et al.)

The Fundamental Multi-Baseline Mode-Mixing Foreground in 21 cm EoR Observations    [PDF]

Bryna J. Hazelton, Miguel F. Morales, Ian S. Sullivan
The primary challenge for experiments measuring the neutral hydrogen power spectrum from the Epoch of Reionization (EoR) are mode-mixing effects where foregrounds from very bright astrophysical sources interact with the instrument to contaminate the EoR signal. In this paper we identify a new type of mode-mixing that occurs when measurements from non-identical baselines are combined for increased power spectrum sensitivity. This multi-baseline effect dominates the mode-mixing power and can contaminate the EoR window, an area in Fourier space previously identified to be relatively free of foreground power. Multi-baseline mode-mixing introduces characteristic shapes into the three dimensional Fourier space that are determined by the instrumental configuration and we develop an iterative approach to identifying and removing mode-mixed power based on these instrumental shapes.
View original: http://arxiv.org/abs/1301.3126

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