Parametrizing Epoch of Reionization foregrounds: a deep survey of low-frequency point-source spectra with the Murchison Widefield Array

• DOI: 10.1093/mnras/stw310
• Publication Date: 2016-02-11T23:30:55Z
• Authors: A. R. Offringa; C. M. Trott; N. Hurley-Walker; M. Johnston-Hollitt; B. McKinley; N. Barry; A. P. Beardsley; J. D. Bowman; F. Briggs; P. Carroll; J. S. Dillon; A. Ewall-Wice; L. Feng; B. M. Gaensler; L. J. Greenhill; B. J. Hazelton; J. N. Hewitt; D. C. Jacobs; H.-S. Kim; P. Kittiwisit; E. Lenc; J. Line; A. Loeb; D. A. Mitchell; M. F. Morales; A. R. Neben; S. Paul; B. Pindor; J. C. Pober; P. Procopio; J. Riding; S. K. Sethi; N. U. Shankar; R. Subrahmanyan; I. S. Sullivan; M. Tegmark; N. Thyagarajan; S. J. Tingay; R. B. Wayth; R. L. Webster; J. S. B. Wyithe
• Keywords: Epoch (astronomy); Point source; Murchison meteorite

Experiments that pursue detection of signals from the Epoch Reionization (EoR) are relying on spectral smoothness source spectra at low frequencies. This article empirically explores effect foreground EoR experiments by measuring high-resolution full-polarization for 586 brightest unresolved sources in one Murchison Widefield Array (MWA) fields using 45 h observation. A novel peeling scheme is used to subtract 2500 visibilities with ionospheric and beam corrections, resulting deepest, confusion-limited MWA image so far. The found be affected instrumental effects, which limit constraints can set source-intrinsic structure. sensitivity power-spectrum analysed, it residuals dominated point spread function sidelobes nearby undeconvolved sources. We release a catalogue describing parameters each measured source.