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

Author(s):Show less -

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

• Document type: Journal article
• Source: Astronomy & Astrophysics; v. 664, p. 19-pg., 2022-08-03.

Abstract

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)

• FAPESP's process: 14/07885-0 - The BINGO telescope: a new 21 cm window for exploring the dark universe and other astrophysics
• Grantee: Elcio Abdalla
• Support Opportunities: Special Projects
• FAPESP's process: 19/05687-0 - The BINGO telescope 21 cm measurements: Baryon Acoustic Oscillations and Non-gaussianities
• Grantee: Carlos Alexandre Wuensche de Souza
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• FAPESP's process: 19/06040-0 - Study of the properties of the universe using the cosmic microwave background radiation and large scale structure tracers
• Grantee: Camila Paiva Novaes
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 15/19936-1 - BINGO: an ultra-sensitive survey of hydrogen and radio continuum emission to measure the dark universe
• Grantee: Michael William Peel
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 18/02026-0 - Development and characterization of the BINGO Telescope instrumentation
• Grantee: Vincenzo Liccardo
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 17/21570-0 - The BINGO telescope: a new 21 cm window for exploring the dark universe and other astrophysical phenomena
• Grantee: Karin Silvia Franzoni Fornazier Guimarães
• Support Opportunities: Scholarships in Brazil - Post-Doctoral