>Magister Scientiae - MSc / Future radio surveys as the Square Kilometer Array (SKA) and its precursor, the "Meer"
Karoo Array Telescope (MeerKAT), will map the Neutral Hydrogen (HI) in large areas of
the sky using the intensity mapping (IM). HI IM is currently one of the most promising ways
of accessing the Large-Scale Structure of the Universe. The distribution of matter in the
Universe not only encodes its composition but also how it evolves and its initial conditions.
An effect on the matter distribution that will be detected by the SKA on the post re-ionization
Universe are the Baryonic Acoustic Oscillations (BAO). While it has been shown that in
single dish mode the SKA can measure the BAO peak in the radial 21cm power spectrum
at low redshifts, this possibility has not yet been studied in detail for the MeerKAT. In this
thesis we construct a set of full sky simulations to test how well MeerKAT will be able
to extract the BAO wiggles along the line of sight. These simulations are done for the
frequencies corresponding to MeerKAT L-band. The maps combine the cosmological HI
signal, systematic noise, cosmological foregrounds and the instrumental telescope beam. A
model-independent estimator is used to extract the BAO wiggles by subtracting a smooth
polynomial component from the 21cm radial power spectrum. We test with simulations
if this estimator is biased and the signal to noise of the extraction. We conclude that we
are able to remove contaminants and recover the cosmological HI signal while not risking
the recovery of the BAO signal. We investigate the effects of varying the sky area and the
observational hours on the signal to noise ratio for the BAO wiggles. We found that for a
HI IM experiment using MeerKAT, the optimal sky area to detect the BAO along the line of
sight is 50% of the sky. With a signal-to-noise ratio of 3.37. This can be achieved with 2000
hours of exposure time
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uwc/oai:etd.uwc.ac.za:11394/6995 |
| Date | January 2019 |
| Creators | Engelbrecht, Brandon |
| Contributors | Santos, Mario, Fonseca, José |
| Publisher | University of the Western Cape |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Rights | University of the Western Cape |
Page generated in 0.0016 seconds