The BINGO project V. Further steps in component separation and bispectrum analysis

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Fornazier, Karin S. F. ; Abdalla, Filipe B. ; Remazeilles, Mathieu ; Vieira, Jordany ; Marins, Alessandro ; Abdalla, Elcio ; Santos, Larissa ; Delabrouille, Jacques ; Mericia, Eduardo ; Landim, Ricardo G. ; Ferreira, Elisa G. M. ; Barosi, Luciano ; Queiroz, Amilcar R. ; Villela, Thyrso ; Wang, Bin ; Wuensche, Carlos A. ; Costa, Andre A. ; Liccardo, Vincenzo ; Novaes, Camila Paiva ; Peel, Michael W. ; dos Santos, Marcelo, V ; Zhang, Jiajun

• Tipo de documento: Artigo Científico
• Fonte: Astronomy & Astrophysics; v. 664, p. 19-pg., 2022-08-03.

Resumo

Context. Observing the neutral hydrogen distribution across the Universe via redshifted 21 cm line intensity mapping constitutes a powerful probe for cosmology. However, the redshifted 21 cm signal is obscured by the foreground emission from our Galaxy and other extragalactic foregrounds. This paper addresses the capabilities of the BINGO survey to separate such signals. Aims. We show that the BINGO instrumental, optical, and simulations setup is suitable for component separation, and that we have the appropriate tools to understand and control foreground residuals. Specifically, this paper looks in detail at the different residuals left over by foreground components, shows that a noise-corrected spectrum is unbiased, and shows that we understand the remaining systematic residuals by analyzing nonzero contributions to the three-point function. Methods. We use the generalized needlet internal linear combination, which we apply to sky simulations of the BINGO experiment for each redshift bin of the survey. We use binned estimates of the bispectrum of the maps to assess foreground residuals left over after component separation in the final map. Results. We present our recovery of the redshifted 21 cm signal from sky simulations of the BINGO experiment, including foreground components. We test the recovery of the 21 cm signal through the angular power spectrum at different redshifts, as well as the recovery of its non-Gaussian distribution through a bispectrum analysis. We find that non-Gaussianities from the original foreground maps can be removed down to, at least, the noise limit of the BINGO survey with such techniques. Conclusions. Our component separation methodology allows us to subtract the foreground contamination in the BINGO channels down to levels below the cosmological signal and the noise, and to reconstruct the 21 cm power spectrum for different redshift bins without significant loss at multipoles 20 less than or similar to l less than or similar to 500. Our bispectrum analysis yields strong tests of the level of the residual foreground contamination in the recovered 21 cm signal, thereby allowing us to both optimize and validate our component separation analysis. (AU)

• Processo FAPESP: 14/07885-0 - O telescópio BINGO: a nova janela de 21cm para exploração do universo escuro e outras questões astrofísicas
• Beneficiário: Elcio Abdalla
• Modalidade de apoio: Auxílio à Pesquisa - Projetos Especiais
• Processo FAPESP: 19/05687-0 - Medidas da radiação em 21 cm com o rádio telescópio BINGO: oscilações acústicas bariônicas e não gaussianidades
• Beneficiário: Carlos Alexandre Wuensche de Souza
• Modalidade de apoio: Auxílio à Pesquisa - Pesquisador Visitante - Internacional
• Processo FAPESP: 19/06040-0 - Estudo das propriedades do universo utilizando dados da radiação cósmica de fundo e de traçadores da estrutura em grande escala
• Beneficiário: Camila Paiva Novaes
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 15/19936-1 - BINGO: uma sonda ultra-sensitiva de hidrogênio e emissão contínua de rádio para medida do setor escuro do universo
• Beneficiário: Michael William Peel
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 18/02026-0 - Desenvolvimento e caracterização da instrumentação do Telescopio BINGO
• Beneficiário: Vincenzo Liccardo
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 17/21570-0 - Telescópio BINGO: uma nova janela de 21 cm para explorar o universo escuro e outros fenômenos astrofísicos
• Beneficiário: Karin Silvia Franzoni Fornazier Guimarães
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado