Holographic Beam Mapping of the CHIME Pathfinder Array

Understand

The Canadian Hydrogen Intensity Mapping Experiment (CHIME) Pathfinder radio telescope is currently surveying the northern hemisphere between 400 and 800 MHz.

• By mapping the large scale structure of neutral hydrogen through its redshifted 21 cm line emission between $z \sim 0.8-2.5$ CHIME will contribute to our understanding of Dark Energy.
• Bright astrophysical foregrounds must be separated from the neutral hydrogen signal, a task which requires precise characterization of the polarized telescope beams.
• Using the DRAO John A.