English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Measurement of fluctuations in diffuse HI 21 cm background radiation from thepost-reionization epoch (z < 6) is a promising avenue to probe the large-scalestructure of the Universe and understand the evolution of galaxies. We observethe European Large-Area ISO Survey-North 1 (ELAIS-N1) field at 300-500 MHzusing the upgraded Giant Meterwave Radio Telescope (uGMRT) and employ the'foreground avoidance' technique to estimate the HI 21 cm power spectrum in theredshift range z = 1.96-3.58. Given the possible systematics that may remain inthe data, we find the most stringent upper limits on the spherically averaged21 cm power spectra at k~1.0 Mpc$^{-1}$ are (58.87 mK)$^2$, (61.49 mK)$^2$,(60.89 mK)$^2$, (105.85 mK)$^2$ at z = 1.96,2.19,2.62 and 3.58, respectively.We use this to constrain the product of neutral HI mass density (Omega_HI) andHI bias (b_HI) to the underlying dark matter density field, [Omega_HI*b_HI], as0.09,0.11,0.12,0.24 at z=1.96,2.19,2.62,3.58, respectively. To the best of ourknowledge these are the first limits on the HI 21 cm power spectra at theredshift range z = 1.96 - 3.58 and would play a significant role to constrainthe models of galaxy formation and evolution.

First multi-redshift limits on post-Epoch of Reionization (post-EoR) 21 cm signal from z = 1.96 - 3.58 using uGMRT