Enhancing EoR limits - spectral accuracy of the MWA  [slides]

David Caro building, Level 7 conference room

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Yuxiang Qin

  • Dr Nichole Barry
    Dr Nichole Barry, -
    University of Melbourne

    Email: nichole.barry[at]unimelb.edu.au

Abstract

Epoch of Reionization observations have the potential to be transformative in the field of cosmology, but this is impossible without unprecedented levels of accuracy in calibration. We enhance EoR upper limits from the Murchison Widefield Array through the improvement of instrumental calibration with in situ simulations, and the reduced limit highlights the precision and accuracy that we must achieve. An in situ calibration simulation verifies our experimental findings, and identifies the fundamental limits of sky-based calibration. We set a precedent for required bandpass accuracy to one part in 105. Our improved EoR upper limit is (80 mK)2 at k=0.2 h Mpc-1 for z=7, an improvement of over a factor of 4 compared to a previous analysis using the exact same data set. These spectral accuracy techniques will influence future pipeline advances in the search for the EoR.