Use this URL to cite or link to this record in EThOS:
Title: Observing the epoch of reionization and dark ages with redshifted 21-cm hydrogen line
Author: Shukla, Hemant
ISNI:       0000 0004 5365 610X
Awarding Body: University of Sussex
Current Institution: University of Sussex
Date of Award: 2015
Availability of Full Text:
Access from EThOS:
Full text unavailable from EThOS. Please try the link below.
Access from Institution:
The billion years subsequent to the Big Bang pose the next challenging frontier for precision cosmology. The concordant cosmological model, ΔCDM, propounds that during this period, the dark matter gravitationally shepherds the baryonic matter to form the primordial large-scale structures. This era is termed the Dark Ages (DA). The following era, the Epoch of Reionization (EoR), leads to the formation of the first stars and galaxies that reionize the permeating neutral hydrogen. The linear polarization of the cosmic background radiation and the Gunn-Peterson troughs in quasar absorption spectra provide indirect evidence for the EoR. Currently, there is no observational evidence for the DA. While state-of-the-art radio telescope arrays, Low Frequency Array (LOFAR) and Square Kilometre Array (SKA), propose various strategies to observe the early phases of the Universe, the advanced simulations employing high-performance computing (HPC) methodologies continue to play significant role in constraining various models based upon limited observational data. Despite a wide range of research, there is no end-to-end simulation solution available to quantifiably address the observational challenges due to statistical and systematic errors including foregrounds, ionosphere, polarization, RFI, instrument stability, and directional dependent gains. This research consolidates the cutting-edge simulation solutions, Cube-P3M, C2-Ray, and MeqTrees, to build an HPC prototype pipeline entitled, Simulating Interferometry Measurements (SIM). To establish and validate the efficacy of the SIM pipeline, the research builds a theoretical framework of two science drivers, viz., the presence of Lymanlimit absorbers and measuring non-Gaussianity from the 21-cm data. Thereafter, using the LOFAR and SKA telescope configurations, the SIM generates data visibility cubes with direction dependent and independent propagation effects. Finally, SIM extracts the original signal through standard techniques exploring the parametric phase-space. Results are presented herein.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: QB0980 Cosmogony. Cosmology