Detecting the 21 cm forest in the 21 cm power spectrum

作者：Ewall Wice Aaron^*; Dillon Joshua S; Mesinger Andrei; Hewitt Jacqueline

来源：Monthly Notices of the Royal Astronomical Society, 2014, 441(3): 2476-2496.

DOI：10.1093/mnras/stu666

• early Universe
• radio continuum: galaxies
• X-rays: galaxies

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 a parts per thousand(3) 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 of the order of similar to 0.1 km(2) (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.

• 出版日期2014-7-1
• 单位MIT