Efficiency of 1/f noise removal in HI intensity mapping experiments by GNILC

• Ano de defesa: 2019
• Autor(a) principal: Morais, Christianne Camargo de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: 1/f noise; Análise de dados; component separation; Cosmologia; cosmology; data analysis; Ruído 1/f; Separação de componentes
• Link de acesso: http://www.teses.usp.br/teses/disponiveis/43/43134/tde-29072019-095427/

One of the greatest mysteries of modern cosmology is the nature and dynamics of dark energy, the component which is believed to be the cause of the Universes accelerated expansion. In this context, the measurement of Baryon Acoustic Oscillations, matter overdensities imprinted in galaxy distribution since recombination epoch, through the observation of HI redshifted 21cm radiation serves as a standard ruler for the Universes expansion history and, consequently, dark energys nature. This work explores the efficiency of a component separation technique called Generalized Needlet Internal Linear Combination in recovering a map of HI plus thermal noise signal as different 1/f noise model parameters are varied and found that this method results in a good recuperation only for large scales, l>= 20, and overestimates the HI plus thermal noise signal around 29% for smaller scales. However, GNILCs parameters were not varied and, therefore, before discarding it as a valid separation method, one should conduct more embracing simulations.