This is a collaborative project, lead 0607838/Backer, non-lead 0607759/Bradley.
When the first stars formed from the densest regions of the evolving cosmic structure, their ultraviolet light stimulated hydrogen-line emission from the intergalactic medium. Although theory suggests that this radiation should be measurable, there are many uncertainties about the amplitude, angular structure, and frequency and redshift variation, of the signal. Progress in our understanding of the Epoch of Reionization (EoR) rests on detection and detailed study of this redshifted 21-cm line, and several experiments are planned or under way. This effort starts simple, with phased developments year by year, and is already deploying test elements sensitive in the 120-205 MHz range. An innovative correlator is under construction. The existing emphasis is on array calibration, wide-field imaging, and understanding how to achieve the stability needed for deep integrations. This continuation project will consolidate and expand, including deploying a larger array in Western Australia, where confounding radio frequency interference is minimal. Together, the northern and southern arrays will produce a catalog of the brightest sources at these frequencies in the entire sky, and prove key capabilities aimed at the future Precision Array to Probe the Epoch of Reionization (PAPER), investigating one of the most fascinating times in the Universe.
This project both benefits from, and helps, related projects, including (but not limited to) the Frequency Agile Solar Radiotelescope, the Allen Telescope Array, and the California Array for Millimeter Astronomy. These are contributions to low frequency radio astronomy in general, as well as to solar physics and space weather. The study is also sharply focused around graduate student and postdoc involvement in instrumentation development. PAPER will also be a pioneer in launching a Radio Astronomy Park and radio quiet zone in a unique part of the globe.
