Multi-frequency angular power spectrum of the 21 cm signal from the Epoch of Reionisation using the Murchison Widefield Array

Abstract

Context. The Multi-frequency Angular Power Spectrum (MAPS) is an alternative to spherically averaged power spectra, and computes local fluctuations in the angular power spectrum without need for line-of-sight spectral transform. Aims. We aimed to test different approaches to MAPS and treatment of the foreground contamination, and compare with the spherically averaged power spectrum, and the single-frequency angular power spectrum. Methods. We applied the MAPS to 110 h of data in z = 6.2-7.5 obtained for the Murchison Widefield Array Epoch of Reionisation experiment to compute the statistical power of 21 cm brightness temperature fluctuations. In the presence of bright foregrounds, a filter w..