High-precision spectroscopy of the Cosmic Microwave Background (CMB) is one of the three themes that have been selected by the ESA Voyage 2050 programme. Several space missions dedicated to the ...measurement of the CMB spectral distortions such as PIXIE, PRISTINE, and FOSSIL have been proposed since 2011. Additionally, balloon-borne projects, such as BISOU, have also been considered as a pathfinder for a future space mission. This paper presents an effort undertaken to define future missions and instruments dedicated to the measurement of the CMB spectral distortions. For this purpose, models allowing to optimize both instrument concept and mission parameters (mission duration, scanning strategy, …) have been developed. It has been applied to two specific cases, FOSSIL, a space mission proposed to answer the ESA M7 call in 2022 , and BISOU, a CNES Phase 0 study for a balloon-borne mission.
Proof of concept measurements of a modular spiral phase plate design able to generate millimetre wavelength beams with an azimuthal mode number of l = ±10 are presented. The plate is comprised of ten ...single modules that interlock to create the full plate assembly, allowing improved machining accuracy compared to standard techniques. Therefore, this design could be used in millimetre wavelength systems that require the manipulation of large OAM modes. The plate was manufactured from polypropylene (index of refraction n ≈ 1.5), and was measured at 100GHz. A three dimensional field scanner was used to measure three near field surfaces behind the plate. Intensity measurements showed the expected OAM intensity ring, and phase measurements showed ten phase dislocations, implying proper functionality.
The Polarized Instrument for Long-wavelength Observation of the Tenuous interstellar medium (
PILOT
) is a balloon-borne experiment that aims to measure the polarized emission of thermal dust at a ...wavelength of 240µm (1.2 THz). The
PILOT
experiment flew from Timmins, Ontario, Canada in 2015 and 2019 and from Alice Springs, Australia in April 2017. The in-flight performance of the instrument during the second flight was described in
1
. In this paper, we present data processing steps that were not presented in
1
and that we have recently implemented to correct for several remaining instrumental effects. The additional data processing concerns corrections related to detector cross-talk and readout circuit memory effects, and leakage from total intensity to polarization. We illustrate the above effects and the performance of our corrections using data obtained during the third flight of
PILOT
, but the methods used to assess the impact of these effects on the final science-ready data, and our strategies for correcting them will be applied to all
PILOT
data. We show that the above corrections, and in particular that for the intensity to polarization leakage, which is most critical for accurate polarization measurements with
PILOT
, are accurate to better than 0.4% as measured on Jupiter during flight#3.
We present a broadband waveguide ortho-mode transducer for the WR10 band that was designed for CLOVER, an astrophysics experiment aiming to characterize the polarization of the cosmic microwave ...background radiation. The design, based on a turnstile junction, was manufactured and then tested using a millimeter-wave vector network analyzer. The average measured return loss and isolation were -22 dB and -45 dB, respectively, across the entire WR10 band
The BINGO project Abdalla, Elcio; Ferreira, Elisa G. M.; Landim, Ricardo G. ...
Astronomy and astrophysics (Berlin),
08/2022, Volume:
664
Journal Article
Peer reviewed
Open access
Context.
Observations of the redshifted 21-cm line of neutral hydrogen (H
I
) are a new and powerful window of observation that offers us the possibility to map the spatial distribution of cosmic H
...I
and learn about cosmology. Baryon Acoustic Oscillations from Integrated Neutral Gas Observations (BINGO) is a new unique radio telescope designed to be one of the first to probe baryon acoustic oscillations (BAO) at radio frequencies.
Aims.
BINGO has two science goals: cosmology and astrophysics. Cosmology is the main science goal and the driver for BINGO’s design and strategy. The key of BINGO is to detect the low redshift BAO to put strong constraints on the dark sector models and test the ΛCDM (cold dark matter) model. Given the versatility of the BINGO telescope, a secondary goal is astrophysics, where BINGO can help discover and study fast radio bursts (FRB) and other transients, as well as study Galactic and extragalactic science. In this paper, we introduce the latest progress of the BINGO project, its science goals, describing the scientific potential of the project for each goal and the new developments obtained by the collaboration.
Methods.
BINGO is a single dish transit telescope that will measure the BAO at low-
z
by making a 3D map of the H
I
distribution through the technique of intensity mapping over a large area of the sky. In order to achieve the project’s goals, a science strategy and a specific pipeline for cleaning and analyzing the produced maps and mock maps was developed by the BINGO team, which we generally summarize here.
Results.
We introduce the BINGO project and its science goals and give a general summary of recent developments in construction, science potential, and pipeline development obtained by the BINGO Collaboration in the past few years. We show that BINGO will be able to obtain competitive constraints for the dark sector. It also has the potential to discover several FRBs in the southern hemisphere. The capacity of BINGO in obtaining information from 21-cm is also tested in the pipeline introduced here. Following these developments, the construction and observational strategies of BINGO have been defined.
Conclusions.
There is still no measurement of the BAO in radio, and studying cosmology in this new window of observations is one of the most promising advances in the field. The BINGO project is a radio telescope that has the goal to be one of the first to perform this measurement and it is currently being built in the northeast of Brazil. This paper is the first of a series of papers that describe in detail each part of the development of the BINGO project.
Ice crystal clouds in the upper troposphere can generate polarization signals at the μK level. This signal can seriously affect very sensitive ground-based searches for E and B modes of cosmic ...microwave background polarization. In this paper, we estimate this effect within the CℓOVER experiment observing bands (97, 150 and 220 GHz) for the selected observing site (Llano de Chajnantor, Atacama desert, Chile). The results show that the polarization signal from the clouds can be of the order of or even bigger than the cosmic microwave background expected polarization. Climatological data suggest that this signal is fairly constant over the whole year in Antarctica. On the other hand, the stronger seasonal variability in Atacama allows for a 50 per cent of clean observations during the dry season.
The Cosmic Microwave Background, the oldest signal that can be seen in the sky, is the direct proof that our Universe was extremely dense and hot several billion years ago. The first experimental ...detection of this fossil radiation has been performed in 1964 and has since then become a powerful tool to probe the formation and evolution of the Universe. Observations of this extremely faint signal pushes the boundaries of many technological developments notably in the fields of optics, detection and cryogenics for space applications.
The BINGO project Wuensche, Carlos A.; Villela, Thyrso; Abdalla, Elcio ...
Astronomy and astrophysics (Berlin),
08/2022, Volume:
664
Journal Article
Peer reviewed
Open access
Context.
The measurement of diffuse 21-cm radiation from the hyperfine transition of neutral hydrogen (H
I
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 H
I
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 H
I
power spectrum in a competitive time frame.
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