Holographic Beam Mapping of the CHIME Pathfinder Array
astro-ph.IM
/ Authors
Philippe Berger, Laura B. Newburgh, Mandana Amiri, Kevin Bandura, Jean-Francois Cliche, Liam Connor, Meiling Deng, Nolan Denman, Matt Dobbs, Mateus Fandino
and 25 more authors
Adam J. Gilbert, Deborah Good, Mark Halpern, David Hanna, Adam D. Hincks, Gary Hinshaw, Carolin Hofer, Andre M. Johnson, Tom L. Landecker, Kiyoshi W. Masui, Juan Mena Parra, Niels Oppermann, Ue-Li Pen, Jeffrey B. Peterson, Andre Recnik, Timothy Robishaw, J. Richard Shaw, Seth Siegel, Kris Sigurdson, Kendrick Smith, Emilie Storer, Ian Tretyakov, Kwinten Van Gassen
/ Abstract
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. Galt 26 m telescope, we have developed a holography instrument and technique for mapping the CHIME Pathfinder beams. We report the status of the instrument and initial results of this effort.