Techniques for the analysis and understanding of cosmic evolution
The 21cm emission from the hyperfine splitting of neutral Hydrogen in the early universe is predicted to provide precise information about the formation and evolution of cosmic structure, complementing the wealth of knowledge gained from the CMB.
21cm cosmology is a relatively new field, and precise measurements of the Epoch of Reionization (EoR) have not yet been achieved. In this work I present 2σ upper limits on the power spectrum of 21cm fluctuations (Δ²(k)) probed at the cosmological wave number k from the Donald C. Backer Precision Array for Probing the Epoch of Reionization (PAPER) 64 element deployment. I find upper limits on Δ²(k) in the range 0.3 < k < 0.6 h/Mpc to be (650 mK)², (450 mK)², (390 mK)², (250 mK)², (280mK)², (250 mK)² at redshifts z = 10.87, 9.93, 8.91, 8.37, 8.13 and 7.48 respectively
Building on the power spectrum analysis, I identify a major limiting factor in detecting the 21cm power spectrum.
This work is concluded by outlining a metric to evaluate the predisposition of redshifted 21cm interferometers to foreground contamination in power spectrum estimation. This will help inform the construction of future arrays and enable high fidelity imaging and
cross-correlation analysis with other high redshift cosmic probes like the CMB and other upcoming all sky surveys. I find future
arrays with uniform (u,v) coverage and small spectral evolution of their response in the (u,v,f) cube can minimize foreground leakage while pursuing 21cm imaging.]]>autKolopanis, Matthew JohnthsBowman, JuddthsMauskopf, PhilipdgcLunardini, CeciliadgcChamberlin, RalphdgcVachaspati, TanmaypblArizona State UniversityengPartial requirement for: Ph.D., Arizona State University, 2018Includes bibliographical references (pages 116-139)Field of study: Physicsby Matthew John Kolopanishttps://hdl.handle.net/2286/R.I.4916600Doctoral DissertationAcademic thesesxiv, 156 pages : color illustrations115278581941630032421156309systemIn CopyrightAll Rights Reserved20182020-05-07T08:30:42TextPhysicsAstronomy21cmCosmic background radiationearly universeRadio AstronomyreionizationCosmic background radiationCosmology