• Fisher Matrix Predictions for Detecting the Cosmological 21-cm Signal with the Ooty Wide Field Array (OWFA)

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      https://www.ias.ac.in/article/fulltext/joaa/036/03/0385-0398

    • Keywords

       

      Cosmology: large scale structure of the Universe; intergalactic medium; diffuse radiation.

    • Abstract

       

      We have used the Fisher matrix formalism to quantify the prospects of detecting the 𝑧 = 3.35 redshifted 21-cm HI power spectrum with the upcoming radio-imterferometric array OWFA. OWFA’s frequency and baseline coverage spans comoving Fourier modes in the range 1.8 × 10−2 ≤ k ≤ 2.7 Mpc−1. The OWFA HI signal, however, is predominantly from the range 𝑘 ≤ 0.2 Mpc−1. The larger modes, though abundant, do not contribute much to the HI signal. In this work, we have focused on combining the entire signal to achieve a detection. We find that a 5 - 𝜎 detection of 𝐴HI is possible with ∼ 150 h of observations, here $A^{2}_{\text{HI}}$ is the amplitude of the HI power spectrum. We have also carried out a joint analysis for 𝐴HI and 𝛽 the redshift space distortion parameter. Our study shows that OWFA is very sensitive to the amplitude of the HI power spectrum. However, the anisotropic distribution of the k modes does not make it very suitable for measuring 𝛽.

    • Author Affiliations

       

      S. Bharadwaj1 2 A. K. Sarkar2 Sk. Saiyad Ali3

      1. Department of Physics, Indian Institute of Technology, Kharagpur 721 302, India.
      2. Centre for Theoretical Studies, Indian Institute of Technology, Kharagpur 721 302, India.
      3. Department of Physics, Jadavpur University, Kolkata 700 032, India.
    • Dates

       
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