RT info:eu-repo/semantics/masterThesis
T1 Breaking the limits of low surface brightness in Ultraviolet
A1 Ruiz Cejudo, Ignacio
A2 Máster Universitario en Astrofísica
K1 methods: data analysis - galaxies: evolution - galaxies: stellar content - galaxies: photometry
- ultraviolet: galaxies
K1 métodos: análisis de datos - galaxias: evolución - galaxias: contenido estelar - galaxias:
fotometría - ultravioleta: galaxias
AB In recent years, various optical surveys have reached unprecedented depths (& 30 mag arcsec−2), facilitatingthe study of fainter galactic structures. However, ultraviolet bands, which are key for the study of the stellarpopulations, remain basically unexplored at these depths. In this work, we present a low surface brightnessanalysis of several nearby galaxies observed by GALEX in the FUV and NUV, adapting and applyingmethods proven effective in optical surveys.We use data from different GALEX programs of 17 galaxies (13 in FUV). 16 of these galaxies are observedby LIGHTS survey, with IC3211 being in one of the fields. A novel approach to background subtractionis proposed, whereby the deviation of the UV background from a Gaussian distribution is modelled as aPoisson process. Furthermore, the PSF deconvolution algorithms developed for optical data are applied inour sample, using a novel set of PSFs for the GALEX bands.This methodology enables the acquisition of reliable surface brightness profiles with depths of∼ 28.5 − 31 mag arcsec−2(3σ; 1000 × 1000), around 1 mag deeper than with the standard techniques.Furthermore, we demonstrate that the application of PSF deconvolution, particularly in FUV, effectivelymitigates the excess of light present in the outer regions of certain galaxies when compared to the standardGALEX pipeline. A qualitative analysis of the results is presented, with a particular focus on the study ofstellar populations at the edge of galaxies. Low surface brightness friendly algorithms in the UV, applied tothe study of edges, will allow us to explore the mechanisms of in-side out growth of the galaxies with muchmore accuracy.
YR 2024
FD 2024
LK http://riull.ull.es/xmlui/handle/915/39214
UL http://riull.ull.es/xmlui/handle/915/39214
LA en
DS Repositorio institucional de la Universidad de La Laguna
RD 23-dic-2024