Christodoulou,_Leonidas_.pdf (31.23 MB)
Galaxy clustering using the GAMA survey
thesis
posted on 2023-06-08, 14:40 authored by Leonidas ChristodoulouWe present a study of the clustering of galaxies in the local Universe (z < 0.4) using the SDSS and GAMA galaxy surveys. Using GAMA spectroscopic redshift we construct a large photometric redshift catalogue from the SDSS imaging data. We then measure the two-point angular correlation function as a function of photometric redshift, absolute magnitude and colour. For all our samples, we estimate the underlying redshift and absolute magnitude distributions using Monte-Carlo resampling. A linear relation between relative bias and L/L* is found to hold down to luminosities L ~ 0.03L*. We find that the redshift dependence of the bias of the L* population can be described by the passive evolution model of linear bias. We confirm an increase in clustering strength for sub-L* red galaxies compared with ~ L* red galaxies at small scales in all redshift bins, whereas for the blue population the correlation length is almost independent of luminosity for ~ L* galaxies and fainter. We proceed by studying the redshift space correlation function from GAMA as functions of luminosity and redshift. For L & L* galaxies we obtain an almost constant pairwise velocity dispersion s12 ˜ 400 km s-1, whereas for L < L* galaxies the pairwise velocity dispersion increases as we go fainter. When measured in different redshift slices the pairwise velocity dispersion as a function of luminosity shows no signs of evolution, however it does present some scale dependence. Our measurements of the growth rate parameter are consistent with the standard ?CDM+GR cosmological model.
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- Published version
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167.0Department affiliated with
- Physics and Astronomy Theses
Qualification level
- doctoral
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- phd
Language
- eng
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University of SussexFull text available
- Yes
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2013-04-17Usage metrics
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