Simulations of 21-cm Intensity Mapping Observations of Baryon Acoustic Oscillations

Several short baseline radio interferometers are being designed to observe baryon acoustic oscillations (BAO) in the large scale structure of the universe . The arrays observe the 21-cm hyperfine transition line produced by neutral hydrogen in the redshift range of 0.5 < z < 3. The science goal is to measure the accelerated expansion of the universe by using BAO wiggles as standard rulers. One such instrument is Tianlai, a short baseline radio array currently being designed to operate in a radio-quiet zone in China. Using NRAO's radio interferometry data reduction and analysis software, CASA, proposed Tianlai array configurations were tested for their ability to recover the BAO wiggles from a simulated sky model. To determine the optimal interferometer configuration for BAO observations, various array parameters were optimized, including: antenna latitudinal and longitudinal separation, antenna radius, and array shape.