Author:
Dasgupta Saswata,Pal Samit Kumar,Bag Satadru,Dutta Sohini,Majumdar Suman,Datta Abhirup,Pathak Aadarsh,Kamran Mohd,Mondal Rajesh,Sarkar Prakash
Abstract
Abstract
We analyse the evolution of the largest ionized region using the topological and
morphological evolution of the redshifted 21-cm signal coming from the neutral hydrogen
distribution during the different stages of reionization. For this analysis, we use the “Largest
Cluster Statistics” — LCS. We mainly study the impact of the array synthesized beam on the LCS
analysis of the 21-cm signal considering the upcoming low-frequency Square Kilometer Array (SKA1-Low) observations using a realistic simulation for such observation based on the
21cmE2E-pipeline using OSKAR. We find that bias in LCS estimation is introduced in synthetic
observations due to the array beam. This in turn shifts the apparent percolation transition point
towards the later stages of reionization. The biased estimates of LCS, occurring due to the effect
of the lower resolution (lack of longer baselines) and the telescope synthesized beam will lead to
a biased interpretation of the reionization history. This is important to note while interpreting
any future 21-cm signal images from upcoming or future telescopes like the SKA, HERA, etc. We
conclude that one may need denser uv-coverage at longer baselines for a better deconvolution of
the array synthesized beam from the 21-cm images and a relatively unbiased estimate of LCS from
such images.
Subject
Astronomy and Astrophysics