Project: Role of instrument response in EoR detection

21-cm signals from the Cosmic Dawn and Epoch of Reionization are many orders of magnitude fainter than Galactic and Extragalactic foreground emission. We can still separate the two, since foregrounds are expected to have a smooth spectral (frequency) signature, whereas the 21-cm signal is expected to fluctuate with frequency. Instruments and data processing algorithms need to maintain as frequency independent a response as possible to facilitate this separation. Radio interferometers however, have a frequency dependent reponse function (also called PSF or point spread function). This leads to spectral fluctuations in the observed data- a potential limitation in our ability to measure the 21-cm signal from the early Universe. In this project, I studied the frequency dependence of the instrumental response in details and showed that there is an "EoR window"- a special region in the observed parameter space that must be devoid of spectral contamination due to a non-ideal intrumental response.

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Murchison Widefield Array