Simulated foreground predictions for HI at z = 3.35 with the Ooty Wide Field Array: I. Instrument and the foregrounds

Understand

Foreground removal is the most important step in detecting the large-scale redshifted HI 21-cm signal.

• Modelling foreground spectra is challenging and is further complicated by the chromatic response of the telescope.
• We present a multi-frequency angular power spectrum (MAPS) estimator for use in a survey for redshifted HI 21-cm emission from z~3.35, and demonstrate its ability to accurately characterize the foregrounds.
• This survey will be carried out with the two wide-field interferometer modes of the upgraded Ooty Radio Telescope, called the Ooty Wide Field Array (OWFA), at 326.5 MHz.