arXiv subjects

Vincenzo Liccardo

Publications and source records attributed to Vincenzo Liccardo.

18 recordsLinked to original sources

arXiv2026

Foreground removal and 21 cm signal estimates: comparing different blind methods for the BINGO Telescope

The BINGO radiotelescope will observe hydrogen distribution using Intensity Mapping (IM) to analyze the Dark Energy paradigm through Baryon Acoustic Oscillations. The target signal is contaminated by unwanted signals and instrumental noise, making accurate estimations essential for characterizing the 21 cm signal. In this study, we evaluated the performance of three blind foreground-removing algorithms - FastICA, GNILC, and GMCA - on the BINGO pipeline. Each method used different approaches to estimate foreground contributions, and we also investigated how the number of simulations for debiasing affects estimation quality. Our findings indicate that using 50 or 400 simulations yields equivalent results at this stage of analysis. All algorithms produced statistically consistent estimates of the 21 cm signal. We used FastICA for estimating and debiasing the HI spectra from five years of observations, which yielded reliable results, although the first channel was affected by edge effects from the mixing matrix. The overall signal-to-noise ratio was 204, and the chi-squared value was 1.8.

astro-ph.CO↗

arXiv2023

The BINGO Project IX: Search for Fast Radio Bursts -- A Forecast for the BINGO Interferometry System

The Baryon Acoustic Oscillations (BAO) from Integrated Neutral Gas Observations (BINGO) radio telescope will use the neutral Hydrogen emission line to map the Universe in the redshift range $0.127 \le z \le 0.449$, with the main goal of probing BAO. In addition, the instrument optical design and hardware configuration support the search for Fast Radio Bursts (FRBs). In this work, we propose the use of a BINGO Interferometry System (BIS) including new auxiliary, smaller, radio telescopes (hereafter \emph{outriggers}). The interferometric approach makes it possible to pinpoint the FRB sources in the sky. We present here the results of several BIS configurations combining BINGO horns with and without mirrors ($4$ m, $5$ m, and $6$ m) and 5, 7, 9, or 10 for single horns. We developed a new {\tt Python} package, the {\tt FRBlip}, which generates synthetic FRB mock catalogs and computes, based on a telescope model, the observed signal-to-noise ratio (S/N) that we used to compute numerically the detection rates of the telescopes and how many interferometry pairs of telescopes (\emph{baselines}) can observe an FRB. FRBs observed by more than one baseline are the ones whose location can be determined. We thus evaluate the performance of BIS regarding FRB localization. We found that BIS will be able to localize 23 FRBs yearly with single horn outriggers in the best configuration (using 10 outriggers of 6 m mirrors), with redshift $z \leq 0.96$; the full localization capability depends on the number and the type of the outriggers. Wider beams are best to pinpoint FRB sources because potential candidates will be observed by more baselines, while narrow beams look deep in redshift. The BIS can be a powerful extension of the regular BINGO telescope, dedicated to observe hundreds of FRBs during Phase 1. Many of them will be well localized with a single horn + 6 m dish as outriggers.(Abridged)

astro-ph.IM↗

arXiv2023

Cosmological constraints from low redshift 21 cm intensity mapping with machine learning

The future 21 cm intensity mapping observations constitute a promising way to trace the matter distribution of the Universe and probe cosmology. Here we assess its capability for cosmological constraints using as a case study the BINGO radio telescope, that will survey the Universe at low redshifts ($0.13 < z < 0.45$). We use neural networks (NNs) to map summary statistics, namely, the angular power spectrum (APS) and the Minkowski functionals (MFs), calculated from simulations into cosmological parameters. Our simulations span a wide grid of cosmologies, sampled under the $Λ$CDM scenario, {$Ω_c, h$}, and under an extension assuming the Chevallier-Polarski-Linder (CPL) parameterization, {$Ω_c, h, w_0, w_a$}. In general, NNs trained over APS outperform those using MFs, while their combination provides 27% (5%) tighter error ellipse in the $Ω_c-h$ plane under the $Λ$CDM scenario (CPL parameterization) compared to the individual use of the APS. Their combination allows predicting $Ω_c$ and $h$ with 4.9% and 1.6% fractional errors, respectively, which increases to 6.4% and 3.7% under CPL parameterization. Although we find large bias on $w_a$ estimates, we still predict $w_0$ with 24.3% error. We also confirm our results to be robust to foreground contamination, besides finding the instrumental noise to cause the greater impact on the predictions. Still, our results illustrate the capability of future low redshift 21 cm observations in providing competitive cosmological constraints using NNs, showing the ease of combining different summary statistics.

astro-ph.CO↗

arXiv2022

Testing synchrotron models and frequency resolution in BINGO 21 cm simulated maps using GNILC

To recover the 21 cm hydrogen line, it is essential to separate the cosmological signal from the much stronger foreground contributions at radio frequencies. The BINGO radio telescope is designed to measure the 21 cm line and detect BAOs using the intensity mapping technique. This work analyses the performance of the GNILC method, combined with a power spectrum debiasing procedure. The method was applied to a simulated BINGO mission, building upon previous work from the collaboration. It compares two different synchrotron emission models and different instrumental configurations, in addition to the combination with ancillary data to optimize both the foreground removal and recovery of the 21 cm signal across the full BINGO frequency band, as well as to determine an optimal number of frequency bands for the signal recovery. We have produced foreground emissions maps using the Planck Sky Model, the cosmological Hi emission maps are generated using the FLASK package and thermal noise maps are created according to the instrumental setup. We apply the GNILC method to the simulated sky maps to separate the Hi plus thermal noise contribution and, through a debiasing procedure, recover an estimate of the noiseless 21 cm power spectrum. We found a near optimal reconstruction of the Hi signal using a 80 bins configuration, which resulted in a power spectrum reconstruction average error over all frequencies of 3%. Furthermore, our tests showed that GNILC is robust against different synchrotron emission models. Finally, adding an extra channel with CBASS foregrounds information, we reduced the estimation error of the 21 cm signal. The optimisation of our previous work, producing a configuration with an optimal number of channels for binning the data, impacts greatly the decisions regarding BINGO hardware configuration before commissioning.

astro-ph.CO↗

arXiv2022

The BINGO project VIII: On the recoverability of the BAO signal on HI intensity mapping simulations

A new and promising technique for observing the Universe and study the dark sector is the intensity mapping of the redshifted 21cm line of neutral hydrogen (HI). The BINGO radio telescope will use the 21cm line to map the Universe in the redshift range $0.127 \le z \le 0.449$, in a tomographic approach, with the main goal of probing BAO. This work presents the forecasts of measuring the transversal BAO signal during the BINGO Phase 1 operation. We use two clustering estimators, the two-point angular correlation function (ACF) and the angular power spectrum (APS), and a template-based method to model the ACF and APS estimated from simulations of the BINGO region and extract the BAO information. The tomographic approach allows the combination of redshift bins to improve the template fitting performance. 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 larger probability of detection of the BAO signal, achieving $\gtrsim 90$\% at higher redshifts. We investigate the contribution from instrumental noise and residual foreground signals and find that the former has the greater impact, getting more significant as the redshift increases, in particular the APS estimator. Indeed, including noise in the analysis increases the uncertainty up to a factor of $\sim 2.2$ at higher redshifts. Foreground residuals, in contrast, do not significantly affect our final uncertainties. In summary, our results show that, even including semi-realistic systematic effects, BINGO has the potential to successfully measure the BAO scale in radio frequencies. (Abridged)

astro-ph.CO↗

arXiv2022

The BINGO Project V: Further steps in Component Separation and Bispectrum Analysis

Observing the neutral hydrogen distribution across the Universe via redshifted 21cm line intensity mapping constitutes a powerful probe for cosmology. However, the redshifted 21cm 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. 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. 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 present our recovery of the redshifted 21cm signal from sky simulations of the BINGO experiment, including foreground components. We test the recovery of the 21cm 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. 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 21cm power spectrum for different redshift bins without significant loss at multipoles $20 \lesssim \ell \lesssim 500$. Our bispectrum analysis yields strong tests of the level of the residual foreground contamination in the recovered 21cm signal, thereby allowing us to both optimize and validate our component separation analysis. (Abridged)

astro-ph.CO↗

arXiv2022

The BINGO Project III: Optical design and optimisation of the focal plane

The BINGO telescope was designed to measure the fluctuations of the 21-cm radiation arising from the hyperfine transition of neutral hydrogen and aims to measure the Baryon Acoustic Oscillations (BAO) from such fluctuations, therefore serving as a pathfinder to future deeper intensity mapping surveys. The requirements for the Phase 1 of the projects consider a large reflector system (two 40 m-class dishes in a crossed-Dragone configuration), illuminating a focal plane with 28 horns to measure the sky with two circular polarisations in a drift scan mode to produce measurements of the radiation in intensity as well as the circular polarisation. In this paper we present the optical design for the instrument. We describe the intensity and polarisation properties of the beams and the optical arrangement of the horns in the focal plane to produce a homogeneous and well-sampled map after the end of Phase 1. Our analysis provides an optimal model for the location of the horns in the focal plane, producing a homogeneous and Nyquist sampled map after the nominal survey time. We arrive at an optimal configuration for the optical system, including the focal plane positioning and the beam behavior of the instrument. We present an estimate of the expected side lobes both for intensity and polarisation, as well as the effect of band averaging on the final side lobes. The cross polarisation leakage values for the final configuration allow us to conclude that the optical arrangement meets the requirements of the project. We conclude that the chosen optical design meets the requirements for the project in terms of polarisation purity, area coverage as well as homogeneity of coverage so that BINGO can perform a successful BAO experiment. We further conclude that the requirements on the placement and r.m.s. error on the mirrors are also achievable so that a successful experiment can be conducted.(Abridged)

astro-ph.IM↗

arXiv2021

The BINGO Project II: Instrument Description

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 $0.127 \le z \le 0.449$. This paper describes the BINGO radio telescope, including the current status of the optics, receiver, observational strategy, calibration, and the site. BINGO has been carefully designed to minimize systematics, being a transit instrument with no moving dishes and 28 horns operating in the frequency range $980 \le ν\le 1260$ 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 $\sim 13\%$ of the sky, with the primary mirror pointing at declination $δ=-15^{\circ}$. The telescope will see an instantaneous declination strip of $14.75^{\circ}$. 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.

astro-ph.IM↗

arXiv2021

The BINGO Project VII: Cosmological Forecasts from 21cm Intensity Mapping

The 21cm line of neutral hydrogen (HI) opens a new avenue in our exploration of the structure and evolution of the Universe. It provides complementary data to the current large-scale structure observations with different systematics, and thus it will be used to improve our understanding of the $Λ$CDM model. Among several radio cosmological surveys designed to measure this line, BINGO is a single-dish telescope mainly designed to detect baryon acoustic oscillations (BAOs) at low redshifts ($0.127< z<0.449$). Our goal is to assess the fiducial BINGO setup and its capabilities of constraining the cosmological parameters, and to analyze the effect of different instrument configurations. We used the Phase 1 fiducial configuration of the BINGO telescope to perform our cosmological forecasts. In addition, we investigated the impact of several instrumental setups, taking into account some instrumental systematics, and different cosmological models. Combining BINGO with Planck temperature and polarization data, the projected constraint improves from a $13\%$ and $25\%$ precision measurement at the $68\%$ confidence level with Planck only to $1\%$ and $3\%$ for the Hubble constant and the dark energy equation of state (EoS), respectively, within the wCDM model. Assuming a Chevallier-Polarski-Linder parameterization, the EoS parameters have standard deviations given by $σ_{w_0} = 0.30$ and $σ_{w_a} = 1.2$, which are improvements on the order of $30\%$ with respect to Planck alone. Also, we can access information about the HI density and bias, obtaining $\sim 8.5\%$ and $\sim 6\%$ precision, respectively, assuming they vary with redshift at three independent bins. The fiducial BINGO configuration will be able to extract significant cosmological information from the HI distribution and provide constraints competitive with current and future cosmological surveys. (Abridged)

astro-ph.CO↗

arXiv2021

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

The large-scale distribution of neutral hydrogen (HI) in the Universe is luminous through its 21 cm emission. The goal of the Baryon Acoustic Oscillations from Integrated Neutral Gas Observations -- BINGO -- radio telescope is to detect baryon acoustic oscillations (BAOs) at radio frequencies through 21 cm intensity mapping (IM). The telescope will span the redshift range 0.127 $< z <$ 0.449 with an instantaneous field-of-view of $14.75^{\circ} \times 6.0^{\circ}$. In this work we investigate different constructive and operational scenarios of the instrument by generating sky maps as they would be produced by the instrument. In doing this we use a set of end-to-end IM mission simulations. The maps will additionally be used to evaluate the efficiency of a component separation method (GNILC). We have simulated the kind of data that would be produced in a single-dish IM experiment such as BINGO. According to the results obtained, we have optimized the focal plane design of the telescope. In addition, the application of the GNILC method on simulated data shows that it is feasible to extract the cosmological signal across a wide range of multipoles and redshifts. The results are comparable with the standard principal component analysis method.

astro-ph.CO↗

arXiv2021

The BINGO Project I: Baryon Acoustic Oscillations from Integrated Neutral Gas Observations

Observations of the redshifted 21-cm line of neutral hydrogen (HI) are a new and powerful window of observation that offers us the possibility to map the spatial distribution of cosmic HI and learn about cosmology. BINGO (Baryon Acoustic Oscillations [BAO] from Integrated Neutral Gas Observations) is a new unique radio telescope designed to be one of the first to probe BAO at radio frequencies. 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 in the dark sector models. 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, 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 in each science and the new developments obtained by the collaboration. 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, and also that will allow for the discovery of several FRBs in the southern hemisphere. The capacity of BINGO in obtaining information from 21-cm is also tested in the pipeline introduced here. 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. (Abridged)

astro-ph.CO↗

arXiv2021

The BINGO Project VI: HI Halo Occupation Distribution and Mock Building

BINGO (Baryon Acoustic Oscillations from Integrated Neutral Gas Observations.) is a radio telescope designed to survey from 980 MHz to 1260 MHz, observe the neutral Hydrogen (HI) 21-cm line and detect BAO (Baryon Acoustic Oscillation) signal with Intensity Mapping technique. Here we present our method to generate mock maps of the 21-cm Intensity Mapping signal covering the BINGO frequency range and related test results. (Abridged)

astro-ph.CO↗

arXiv2021

Baryon Acoustic Oscillations from Integrated Neutral Gas Observations: an instrument to observe the 21cm hydrogen line in the redshift range 0.13 $<$ z $<$ 0.45 -- status update

BINGO (BAO from Integrated Neutral Gas Observations) is a unique radio telescope designed to map the intensity of neutral hydrogen distribution at cosmological distances, making the first detection of Baryon Acoustic Oscillations (BAO) in the frequency band 980 MHz - 1260 MHz, corresponding to a redshift range $0.127 < z < 0.449$. BAO is one of the most powerful probes of cosmological parameters and BINGO was designed to detect the BAO signal to a level that makes it possible to put new constraints on the equation of state of dark energy. The telescope will be built in Paraíba, Brazil and consists of two $\thicksim$ 40m mirrors, a feedhorn array of 28 horns, and no moving parts, working as a drift-scan instrument. It will cover a $15^{\circ}$ declination strip centered at $\sim δ=-15^{\circ}$, mapping $\sim 5400$ square degrees in the sky. The BINGO consortium is led by University of São Paulo with co-leadership at National Institute for Space Research and Campina Grande Federal University (Brazil). Telescope subsystems have already been fabricated and tested, and the dish and structure fabrication are expected to start in late 2020, as well as the road and terrain preparation.

astro-ph.CO↗

arXiv2015

Development of superconducting Klystron cavity for the Mario Schenberg gravitational wave detector

Superconducting reentrant cavities can be used in parametric transducers for Gravitational Wave antennas. The Mario Schenberg detector, which is being built by the GRAVITON group at Instituto Nacional de Pesquisas Espaciais (INPE), basically consists of a resonant mass (ball) and a set of parametric transducers in order to monitor the fundamental modes of vibration. When coupled to the antenna, the transducer-sphere system will work as a mass-spring system. In this work the main task is the development of parametric transducers consisting of reentrant superconducting cavity with high performance to be implemented in the Mario Schenberg detector. Many geometries, materials and designs have been tested and compared to optimize parameters such as electric and mechanical Q-factor. The aim is the construction of a complete set of nine parametric transducers that, attached to the spherical antenna, will possibly reach the sensitivity $h$ $\sim$ 10$^{-22}$ $Hz$$^{-1/2}$ in the near future.

astro-ph.IM↗

arXiv2015

Simulation of a Laue lens with bent Ge(111) crystals

In the context of Laue project for focusing hard X-/ soft gamma-rays, an entire Laue lens, using bent Ge(111) crystal tiles, with 40 meters curvature radius, is simulated with a focal length of 20 meters. The focusing energy band is between 80 keV and 600 keV. The distortion of the output image of the lens on the focal plane due to the effect of crystal tile misalignment as well as the radial distortion arising from the curvature of the crystal is discussed in detail. Expected detection efficiency and instrument background is also estimated. Finally the sensitivity of the Laue lens is calculated. A quantitative analysis of the results of these simulation is also presented.

physics.ins-det↗

arXiv2013

Results of the simulations of the petal/lens as part of the LAUE project

In the context of the LAUE project for focusing hard X-/gamma rays, a petal of the complete lens is being assembled at the LARIX facility in the Department of Physics and Earth Science of the University of Ferrara. The lens petal structure is composed of bent Germanium and Gallium Arsenide crystals in transmission geometry. We present the expectations derived from a mathematical model of the lens petal. The extension of the model for the complete LAUE project in the 90 -- 600 keV energy range will be discussed as well. A quantitative analysis of the results of these simulations is also presented.

astro-ph.IM↗

arXiv2013

Bent crystal selection and assembling for the LAUE project

For the first time, with the Laue project, bent crystals are being used for focusing photons in the 80-300 keV energy range. The advantage is their high reflectivity and better Point Spread Function with respect to the mosaic flat crystals. Simulations have already shown their excellent focusing capability which makes them the best candidates for a Laue lens whose sensitivity is also driven by the size of the focused spot. Selected crystals are Germanium (perfect, (111)) and Gallium Arsenide (mosaic, (220)) with 40 m curvature radius to get a spherical lens with 20 m long focal length. A lens petal is being built. We report the measurement technique by which we are able to estimate the exact curvature of each tile within a few percent of uncertainty and their diffraction efficiency. We also discuss some results.

astro-ph.IM↗

arXiv2012

Expected performance of a Laue lens based on bent crystals

In the context of the LAUE project devoted to build a long focal length focusing optics for soft gamma-ray astronomy (70/100 keV to $>$600 keV), we present results of simulation of a Laue lens, based on bent crystals in different assembling configurations (quasi-mosaic and reflection-like geometries). The main aim is to significantly overcome the sensitivity limits of the current generation of gamma-ray telescopes and improve the imaging capability.

astro-ph.IM↗