2021/03/31 by Janakee Raste, Girish Kulkarni, Laura C. Keating +3 · 14 citations
Engineering · Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Dark Ages #Galaxy #HERA #Intergalactic medium #LOFAR #Lyman-alpha forest #Particle physics #Physics #Quantum chromodynamics #Quasar #Radio Astronomy Observations and Technology #Radio Wave Propagation Studies #Radio telescope #Redshift #Reionization #Spectral density #astro-ph.CO
paper · pdf · doi:10.1093/mnras/stab2424
published in Monthly Notices of the Royal Astronomical Society 507(4), 4684-4696 (Oxford University Press) · 14 pages, 6 figures, 2 tables. Accepted for publication in MNRAS
openalex created_date 2021/03/15 · arxiv created 2021/08/18 · openalex publication_date 2021/08/27 · arxiv updated 2021/09/08 · openalex updated_date 2026/08/05
ABSTRACT Our understanding of the intergalactic medium at redshifts z = 5–6 has improved considerably in the last few years due to the discovery of quasars with z > 6 that enable Lyman-α forest studies at these redshifts. A realization from this has been that hydrogen reionization could end much later than previously thought, so that large ‘islands’ of cold, neutral hydrogen could exist in the IGM at redshifts z = 5–6. By using radiative transfer simulations of the IGM, we consider the implications of the presence of these neutral hydrogen islands for the 21-cm power spectrum signal and its potential detection by experiments such as hera, ska, lofar, and mwa. In contrast with previous models of the 21-cm signal, we find that thanks to the late end of reionization the 21-cm power in our simulation continues to be as high as Δ 221=10~mK2 at k ∼ 0.1 h cMpc−1 at z = 5–6. This value of the power spectrum is several orders of magnitude higher than that in conventional models considered in the literature for these redshifts. Such high values of the 21-cm power spectrum should be detectable by hera and ska1-low in ∼1000 h, assuming optimistic foreground subtraction. This redshift range is also attractive due to relatively low sky temperature and potentially greater abundance of multiwavelength data.