The BINGO project

VIII. Recovering the BAO signal in HI intensity mapping simulations

¹ Instituto Nacional de Pesquisas Espaciais, Av. dos Astronautas 1758, Jardim da Granja, São José dos Campos, SP, Brazil
e-mail: camila.novaes@inpe.br, camilapnovaes@gmail.com
² Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, PR China
³ University College London, Gower Street, London WC1E 6BT, UK
⁴ Instituto de Física, Universidade de São Paulo, R. do Matão, 1371 – Butantã, 05508-09 São Paulo, SP, Brazil
⁵ Department of Physics and Electronics, Rhodes University, PO Box 94 Grahamstown 6140, South Africa
⁶ CNRS-UCB International Research Laboratory, Centre Pierre Binétruy, IRL2007, CPB-IN2P3, Berkeley, USA
⁷ Laboratoire Astroparticule et Cosmologie (APC), CNRS/IN2P3, Université Paris Diderot, 75205 Paris Cedex 13, France
⁸ IRFU, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
⁹ Department of Astronomy, School of Physical Sciences, University of Science and Technology of China, Hefei, Anhui 230026, PR China
¹⁰ Instituto de Física de Cantabria (CSIC-Universidad de Cantabria), Avda. de los Castros s/n, 39005 Santander, Spain
¹¹ Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
¹² Center for Gravitation and Cosmology, College of Physical Science and Technology, Yangzhou University, Yangzhou 225009, PR China
¹³ School of Aeronautics and Astronautics, Shanghai Jiao Tong University, Shanghai 200240, PR China
¹⁴ Technische Universität München, Physik-Department T70, James-Franck-Strasse 1, 85748 Garching, Germany
¹⁵ Unidade Acadêmica de Física, Universidade Federal de Campina Grande, R. Aprígio Veloso, Bodocongó, 58429-900 Campina Grande, PB, Brazil
¹⁶ Centro de Gestão e Estudos Estratégicos SCS Qd 9, Lote C, Torre C S/N Salas 401 a 405, 70308-200 Brasília, DF, Brazil
¹⁷ Instituto de Física, Universidade de Brasília, Campus Universitário Darcy Ribeiro, 70910-900 Brasília, DF, Brazil
¹⁸ College of Science, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, PR China
¹⁹ Kavli IPMU (WPI), UTIAS, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583, Japan

Received: 19 January 2022
Accepted: 29 July 2022

Abstract

Context. A new and promising technique for observing the Universe and study the dark sector is the intensity mapping of the redshifted 21 cm line of neutral hydrogen (H I). The Baryon Acoustic Oscillations [BAO] from Integrated Neutral Gas Observations (BINGO) radio telescope will use the 21 cm line to map the Universe in the redshift range 0.127 ≤ z ≤ 0.449 in a tomographic approach, with the main goal of probing the BAO.

Aims. This work presents the forecasts of measuring the transversal BAO signal during the BINGO phase 1 operation.

Methods. We used two clustering estimators: the two-point angular correlation function (ACF) in configuration space, and the angular power spectrum (APS) in harmonic space. We also used a template-based method to model the ACF and APS estimated from simulations of the BINGO region and to extract the BAO information. The tomographic approach allows the combination of redshift bins to improve the template fitting performance. We computed the ACF and APS for each of the 30 redshift bins and measured the BAO signal in three consecutive redshift blocks (lower, intermediate, and higher) of ten channels each. Robustness tests were used to evaluate several aspects of the BAO fitting pipeline for the two clustering estimators.

Results. We find that each clustering estimator shows different sensitivities to specific redshift ranges, although both of them perform better at higher redshifts. In general, the APS estimator provides slightly better estimates, with smaller uncertainties and a higher probability of detecting the BAO signal, achieving ≳90% at higher redshifts. We investigate the contribution from instrumental noise and residual foreground signals and find that the former has the greater impact. It becomes more significant with increasing redshift, in particular for the APS estimator. When noise is included in the analysis, the uncertainty increases by up to a factor of ∼2.2 at higher redshifts. Foreground residuals, in contrast, do not significantly affect our final uncertainties.

Conclusions. In summary, our results show that even when semi-realistic systematic effects are included, BINGO has the potential to successfully measure the BAO scale at radio frequencies.