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Structure morphologique et populations stellaires d'un échantillon de galaxies spirales

Show simple item record Karera, Prime 2017-05-16T08:30:16Z 2017-05-16T08:30:16Z 2016
dc.description.abstract To characterize the morphological structure and the stellar populations of a sample of thirteen spiral galaxies, we analyzed WISE and GALEX images, and constructed pixel magnitude-magnitude and color-magnitude diagrams. The diagrams reveal groups of pixels which spatially trace the structural components of the galaxies. The diagrams and radial surface brightness profiles indicate that variations in the surface mass densities of the old stellar populations play a major role in the differentiation of structures. We estimate the ages of the young stellar complexes and the dust extinction in these galaxies by means of comparison to models of simple stellar populations born from an instantaneous burst. The study of these properties is possible through the combination of ultraviolet and infrared data and to the high sensitivity of the ultraviolet colour to variations in age. We observe an extinction gradient whose slope depend on the presence of a bar or a nuclear activity : the exctinction decreases with respect to the galactocentric distance and the slope is smaller for galaxies with a bar or with a nuclear activity. There is an age gradient as well, with the external regions being less evolved than the central ones, except for the late-type galaxies. en_US
dc.description.sponsorship University of Rwanda en_US
dc.language.iso en en_US
dc.publisher Université Laval en_US
dc.subject Spiral galaxies en_US
dc.subject Québec, Canada en_US
dc.subject GALEX en_US
dc.subject WISE en_US
dc.title Structure morphologique et populations stellaires d'un échantillon de galaxies spirales en_US
dc.type Thesis en_US

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