The Epoch of Reionization 21-cm bispectrum: the impact of light-cone effects and detectability
Reads0
Chats0
TLDR
In this article, the spherically averaged bispectrum of the 21-cm signal from the Epoch of Reionization (EoR) was calculated using a semi-numerical light-cone simulation and an ensemble of 50 independent realisations of the signal to estimate the cosmic variance errors.Abstract:
We study the spherically averaged bispectrum of the 21-cm signal from the Epoch of Reionization (EoR). This metric provides a quantitative measurement of the level of non-Gaussianity of the signal which is expected to be high. We focus on the impact of the light-cone effect on the bispectrum and its detectability with the future SKA-Low telescope. Our investigation is based on semi-numerical light-cone simulation and an ensemble of 50 independent realisations of the 21-cm signal to estimate the cosmic variance errors. We calculate the bispectrum with a new, optimised direct estimation method, DviSukta which calculates the bispectrum for all possible unique triangles. We find that the light-cone effect becomes important on scales $k_1 \lesssim 0.1\,{\rm Mpc}^{-1}$ where for most triangle shapes the cosmic variance errors dominate. Only for the squeezed limit triangles, the impact of the light-cone effect exceeds the cosmic variance. Combining the effects of system noise and cosmic variance we find that $\sim 3\sigma$ detection of the bispectrum is possible for all unique triangle shapes around a scale of $k_1 \sim 0.2\,{\rm Mpc}^{-1}$, and cosmic variance errors dominate above and noise errors below this length scale. Only the squeezed limit triangles are able to achieve a more than $5\sigma$ significance over a wide range of scales, $k_1 \lesssim 0.8\,{\rm Mpc}^{-1}$. Our results suggest that among all the possible triangle combinations for the bispectrum, the squeezed limit one will be the most measurable and hence useful.read more
Citations
More filters
Posted Content
Improving constraints on the reionization parameters using 21-cm bispectrum
TL;DR: In this paper, the authors demonstrate that bispectra for large and intermediate length scales and for all unique $k$-triangle shapes provide tighter constraints on the EoR parameters compared to the power spectrum or the bispectral for a limited number of shapes of $k-triangles.
Journal ArticleDOI
Improving constraints on the reionization parameters using 21-cm bispectrum
TL;DR: In this paper , the authors demonstrate that bispectra for large and intermediate length scales and for all unique k-triangle shapes provide tighter constraints on the EoR parameters compared to the power spectrum or the bispectral for a limited number of shapes of k -triangles.
Journal ArticleDOI
Distinguishing reionization models using the largest cluster statistics of the 21-cm maps
Aadarsh Pathak,Satadru Bag,Saswata Dasgupta,Suman Majumdar,Rajesh Mondal,Mohd Kamran,Prakash Sarkar +6 more
TL;DR: In this article , the shape and morphology of the ionized regions as they evolve in different reionization models in terms of the Shape Finders (SFs) that are ratios of the Minkowski functionals.
Journal ArticleDOI
Exploring the cosmic dawn and epoch of reionization with the 21 cm line
TL;DR: In this paper , the authors introduce the basic physics of the 21 cm line and how the first stars impact on the 21cm line signal, and briefly summarize how they extract astrophysical information from the 21 km line signal by means of statistical and machine learning approaches.
Journal ArticleDOI
Probing early Universe through redshifted 21-cm signal: Modeling and observational challenges
Abinash Kumar Shaw,Arnab Chakraborty,Mohd Kamran,Raghunath Ghara,Samir Choudhuri,Sk. Saiyad Ali,Srijita Pal,A. Ghosh,Jais Kumar,Prasun Dutta,Anjan Kumar Sarkar +10 more
TL;DR: In this paper , the authors summarized the collective effort of Indian astronomers to understand the origin of the redshifted 21 cm signal, sources of first ionizing photons, their propagation through the IGM, various cosmological effects on the expected 21-cm signal, various statistical measures of the signal like power spectrum, bispectrum, etc.
References
More filters
The large-scale structure of the universe
TL;DR: Peebles as discussed by the authors argues that the evolution of the early universe went from a nearly uniform initial state to a progressively more irregular and clumpy universe, based on the largest known structures of the universe.
Journal ArticleDOI
The mass function of dark matter haloes
Adrian Jenkins,Carlos S. Frenk,Simon D. M. White,Jörg M. Colberg,Shaun Cole,August E. Evrard,Hugh M. P. Couchman,Naoki Yoshida +7 more
TL;DR: In this article, the authors combine data from a number of N-body simulations to predict the abundance of dark halos in cold dark matter (CDM) universes over more than four orders of magnitude in mass.
Journal ArticleDOI
An excursion set model of hierarchical clustering: ellipsoidal collapse and the moving barrier
Ravi K. Sheth,Giuseppe Tormen +1 more
TL;DR: In this article, the authors compare the excursion set predictions associated with spherical and ellipsoidal collapse and show that the spherical collapse-based moving barrier model provides a better description of what we measure in the numerical simulations than the spherical collapsing-based constant barrier model, although the agreement between model and simulations is better at large lookback times.
Journal ArticleDOI
21 cm cosmology in the 21st century
TL;DR: This review detail the physics that governs the 21 cm signal and describe what might be learnt from upcoming observations, and generalize the discussion to intensity mapping of other atomic and molecular lines.
Journal ArticleDOI
Cosmological Parameter Estimation Using 21 cm Radiation from the Epoch of Reionization
TL;DR: In this paper, the authors quantify all the effects that break the spherical symmetry of the three-dimensional 21 cm power spectrum and show that it will be difficult to place competitive constraints on cosmological parameters with any of the considered methods.