The BINGO project

Abstract

Context. The measurement of diffuse 21-cm radiation from the hyperfine transition of neutral hydrogen (Hi signal) in different redshifts is an important tool for modern cosmology. However, detecting this faint signal with non-cryogenic receivers in single-dish telescopes is a challenging task. The BINGO (Baryon Acoustic Oscillations from Integrated Neutral Gas Observations) radio telescope is an instrument designed to detect baryonic acoustic oscillations (BAOs) in the cosmological Hi signal, in the redshift interval 0.127 ≤ z ≤ 0.449. Aims. This paper describes the BINGO radio telescope, including the current status of the optics, receiver, observational strategy, calibration, and the site. Methods. BINGO has been carefully designed to minimize systematics, being a transit instrument with no moving dishes and 28 horns operating in the frequency range 980 ≤ ν ≤ 1260 MHz. Comprehensive laboratory tests were conducted for many of the BINGO subsystems and the prototypes of the receiver chain, horn, polarizer, magic tees, and transitions have been successfully tested between 2018-2020. The survey was designed to cover ∼ 13% of the sky, with the primary mirror pointing at declination δ = −15 • . The telescope will see an instantaneous declination strip of 14.75 • . Results. The results of the prototype tests closely meet those obtained during the modeling process, suggesting BINGO will perform according to our expectations. After one year of observations with a 60% duty cycle and 28 horns, BINGO should achieve an expected sensitivity of 102 µK per 9.33 MHz frequency channel, one polarization, and be able to measure the Hi power spectrum in a competitive time frame.

Further understanding the interaction between dark energy and dark matter: current status and future directions

“…The project has been described in the literature. The theoretical and instrumental aspects are given in [2,339], the optical design in [3], the mission simulation in [222], further steps in component separation and bispectrum analysis in [150], a mock description in [365] and cosmological forecasting in [106].…”

The BINGO Project IV: Simulations for mission performance assessment and preliminary component separation steps

“…It will provide excellent polarization performance and very low sidelobe levels required for Hi IM. For a detailed description of the project and the instrument, see the companion papers I and II Abdalla et al (2021a); Wuensche et al (2021).…”

“…Each horn will be secured in the focal plane by a hexagonal casing, which works both as a transportation box and assembly cell. It will encapsulate the horn + transitions + polarizer + magic tee + receiver box (Wuensche et al 2021). With this hexagon concept, it is likely no additional external structure will be needed to position the horn array structure.…”

“…A good front end for a radio telescope designed for intensity mapping with the required stability will exhibit a low knee frequency, ideally of the order of one thousandth of a hertz. The use of correlation receivers using colfets as reference sources in the BINGO telescope will allow for efficient accounting of the 1/ f noise contribution (see Wuensche et al 2021). To reduce the stripe contamination in the maps, we need to carefully measure the relative gains of the individual receivers and determine the beam contribution for each horn before combining the signals from all the beams.…”

“…This is the fourth (IV) of a series of papers describing the BINGO project. The theoretical and instrumental projects are in papers I and II (Abdalla et al 2021a;Wuensche et al 2021), the optical design in paper III (Abdalla et al 2021b), the component separation and correlations in paper V (Fornazier et al 2021), the simulations for a mock 21-cm catalog are described in paper VI (Zhang et al 2021) and the cosmological forecasts for BINGO in paper VII (Costa et al 2021).…”