2013/10/31 by Aaron Ewall-Wice, Joshua S. Dillon, Andrei Mesinger +1 · 1 citation
Physics and Astronomy · #astro-ph.CO
paper · pdf · doi:10.1093/mnras/stu666
published as Monthly Notices of the Royal Astronomical Society 2014 441 (2): 2476-2496 · 20 pages, 17 figures, accepted for publication in MNRAS
arxiv created 2014/06/02 · arxiv updated 2014/06/03
We describe a new technique for constraining the radio loud population of active galactic nuclei at high redshift by measuring the imprint of 21 cm spectral absorption features (the 21 cm forest) on the 21 cm power spectrum. Using semi-numerical simulations of the intergalactic medium and a semi-empirical source population we show that the 21 cm forest dominates a distinctive region of k-space, k \gtrsim 0.5 Mpc-1. By simulating foregrounds and noise for current and potential radio arrays, we find that a next generation instrument with a collecting area on the order of ∼ 0.1km2 (such as the Hydrogen Epoch of Reionization Array) may separately constrain the X-ray heating history at large spatial scales and radio loud active galactic nuclei of the model we study at small ones. We extrapolate our detectability predictions for a single radio loud active galactic nuclei population to arbitrary source scenarios by analytically relating the 21 cm forest power spectrum to the optical depth power spectrum and an integral over the radio luminosity function.