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Studying the morphology of HI isodensity surfaces during reionization using Shapefinders and percolation analysis
journal contribution
posted on 2023-06-09, 18:57 authored by Satadru Bag, Rajesh Mondal, Prakash Sarkar, Somnath Bharadwaj, Tirthankar Roy Choudhry, Varun SahniMinkowski functionals and Shapefinders shed light on the connectedness of large-scale structure by determining its topology and morphology. We use a sophisticated code, SURFGEN2, to measure the Minkowski functionals and Shapefinders of individual clusters by modelling cluster surfaces using the Marching Cube 33 triangulation algorithm. In this paper, we study the morphology of simulated neutral hydrogen (HI) density fields using Shapefinders at various stages of reionization from the excursion set approach. Accompanying the Shapefinders, we also employ the ‘largest cluster statistic’ to understand the percolation process. Percolation curves demonstrate that the non-Gaussianity in the H?I field increases as reionization progresses. The large clusters in both the H?I overdense and underdense excursion sets possess similar values of ‘thickness’ (T), as well as ‘breadth’ (B), but their third Shapefinder – ‘length’ (L) – becomes almost proportional to their volume. The large clusters in both H?I overdense and underdense segments are overwhelmingly filamentary. The ‘cross-section’ of a filamentary cluster can be estimated using the product of the first two Shapefinders, T × B. Hence the cross-sections of the large clusters at the onset of percolation do not vary much with volume and their sizes only differ in terms of their lengths. This feature appears more vividly in H?I overdense regions than in underdense regions and is more pronounced at lower redshifts which correspond to an advanced stage of reionization.
History
Publication status
- Published
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- Published version
Journal
Monthly Notices of the Royal Astronomical SocietyISSN
0035-8711Publisher
Oxford University PressExternal DOI
Issue
2Volume
485Page range
2235-2251Department affiliated with
- Physics and Astronomy Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2019-09-24First Open Access (FOA) Date
2019-09-24First Compliant Deposit (FCD) Date
2019-09-05Usage metrics
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