An integrated system at the Bleien Observatory for mapping the Galaxy

Abstract

We describe the design and performance of the hardware system at the Bleien Observatory. The system is designed to deliver a map of the Galaxy at 990-1260 MHz for studying the foreground contamination of low-redshift (z = 0.13-0.43) HI intensity mapping experiments as well as other astronomical Galactic studies. This hardware system is composed of a 7 m parabolic dish, a dual-polarization corrugated horn feed, a pseudo-correlation receiver, a Fast Fourier Transform spectrometer and an integrated control system that controls and monitors the progress of the data collection. The main innovative designs in the hardware are (1) the pseudo-correlation receiver and the cold reference source within (2) the high dynamic range, high frequency resolution spectrometer and (3) the phase-switch implementation of the system. This is the first time these technologies are used together for an L-band radio telescope to achieve an electronically stable system, which is an essential first step for wide-field cosmological measurements. This work demonstrates the prospects and challenges for future HI intensity mapping experiments.