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R. B. Barreiro

Publications and source records attributed to R. B. Barreiro.

At least 55 records · Page 3Linked to original sources
arXiv2023

Tensor-to-scalar ratio forecasts for extended LiteBIRD frequency configurations

LiteBIRD is a planned JAXA-led CMB B-mode satellite experiment aiming for launch in the late 2020s, with a primary goal of detecting the imprint of primordial inflationary gravitational waves. Its current baseline focal-plane configuration includes 15 frequency bands between 40 and 402 GHz, fulfilling the mission requirements to detect the amplitude of gravitational waves with the total uncertainty on the tensor-to-scalar ratio, $δr$, down to $δr<0.001$. A key aspect of this performance is accurate astrophysical component separation, and the ability to remove polarized thermal dust emission is particularly important. In this paper we note that the CMB frequency spectrum falls off nearly exponentially above 300 GHz relative to the thermal dust SED, and a relatively minor high frequency extension can therefore result in even lower uncertainties and better model reconstructions. Specifically, we compare the baseline design with five extended configurations, while varying the underlying dust modeling, in each of which the HFT (High-Frequency Telescope) frequency range is shifted logarithmically towards higher frequencies, with an upper cutoff ranging between 400 and 600 GHz. In each case, we measure the tensor-to-scalar ratio $r$ uncertainty and bias using both parametric and minimum-variance component-separation algorithms. When the thermal dust sky model includes a spatially varying spectral index and temperature, we find that the statistical uncertainty on $r$ after foreground cleaning may be reduced by as much as 30--50 % by extending the upper limit of the frequency range from 400 to 600 GHz, with most of the improvement already gained at 500 GHz. We also note that a broader frequency range leads to better ability to discriminate between models through higher $χ^2$ sensitivity. (abridged)

astro-ph.CO↗
arXiv2023

Planck 2013 results X. Energetic particle effects: characterization, removal, and simulation

We describe the detection, interpretation, and removal of the signal resulting from interactions of high energy particles with the \Planck\ High Frequency Instrument (HFI). There are two types of interactions: heating of the 0.1\,K bolometer plate; and glitches in each detector time stream. The transient responses to detector glitch shapes are not simple single-pole exponential decays and fall into three families. The glitch shape for each family has been characterized empirically in flight data and these shapes have been used to remove glitches from the detector time streams. The spectrum of the count rate per unit energy is computed for each family and a correspondence is made to the location on the detector of the particle hit. Most of the detected glitches are from Galactic protons incident on the die frame supporting the micro-machined bolometric detectors. In the \Planck\ orbit at L2, the particle flux is around $5\,{\rm cm}^{-2}\,{\rm s}^{-1}$ and is dominated by protons incident on the spacecraft with energy $>$39\,MeV, at a rate of typically one event per second per detector. Different categories of glitches have different signatures in the time stream. Two of the glitch types have a low amplitude component that decays over nearly 1\,s. This component produces excess noise if not properly removed from the time-ordered data. We have used a glitch detection and subtraction method based on the joint fit of population templates. The application of this novel glitch subtraction method removes excess noise from the time streams. Using realistic simulations, we find that this method does not introduce signal bias into the \Planck\ data.

astro-ph.CO↗
arXiv2023

Morphological Analysis of the Polarized Synchrotron Emission with WMAP and Planck

The bright polarized synchrotron emission, away from the Galactic plane, originates mostly from filamentary structures. We implement a filament finder algorithm which allows the detection of bright elongated structures in polarized intensity maps. We analyse the sky at 23 and 30 GHz as observed respectively by WMAP and Planck. We identify 19 filaments, 13 of which have been previously observed. For each filament, we study the polarization fraction, finding values typically larger than for the areas outside the filaments, excluding the Galactic plane, and a fraction of about 30% is reached in two filaments. We study the polarization spectral indices of the filaments, and find a spectral index consistent with the values found in previous analysis (about -3.1) for more diffuse regions. Decomposing the polarization signals into the $E$ and $B$ families, we find that most of the filaments are detected in $P_E$, but not in $P_B$. We then focus on understanding the statistical properties of the diffuse regions of the synchrotron emission at 23 GHz. Using Minkowski functionals and tensors, we analyse the non-Gaussianity and statistical isotropy of the polarized intensity maps. For a sky coverage corresponding to 80% of the fainter emission, and on scales smaller than 6 degrees ($\ell > 30$), the deviations from Gaussianity and isotropy are significantly higher than 3$σ$. The level of deviation decreases for smaller scales, however, it remains significantly high for the lowest analised scale ($\sim 1.5^\circ$). When 60% sky coverage is analysed, we find that the deviations never exceed 3$σ$. Finally, we present a simple data-driven model to generate non-Gaussian and anisotropic simulations of the synchrotron polarized emission. The simulations are fitted in order to match the spectral and statistical properties of the faintest 80% sky coverage of the data maps.

astro-ph.CO↗
arXiv2023

Probing Cosmic Inflation with the LiteBIRD Cosmic Microwave Background Polarization Survey

LiteBIRD, the Lite (Light) satellite for the study of B-mode polarization and Inflation from cosmic background Radiation Detection, is a space mission for primordial cosmology and fundamental physics. The Japan Aerospace Exploration Agency (JAXA) selected LiteBIRD in May 2019 as a strategic large-class (L-class) mission, with an expected launch in the late 2020s using JAXA's H3 rocket. LiteBIRD is planned to orbit the Sun-Earth Lagrangian point L2, where it will map the cosmic microwave background (CMB) polarization over the entire sky for three years, with three telescopes in 15 frequency bands between 34 and 448 GHz, to achieve an unprecedented total sensitivity of 2.2$μ$K-arcmin, with a typical angular resolution of 0.5$^\circ$ at 100 GHz. The primary scientific objective of LiteBIRD is to search for the signal from cosmic inflation, either making a discovery or ruling out well-motivated inflationary models. The measurements of LiteBIRD will also provide us with insight into the quantum nature of gravity and other new physics beyond the standard models of particle physics and cosmology. We provide an overview of the LiteBIRD project, including scientific objectives, mission and system requirements, operation concept, spacecraft and payload module design, expected scientific outcomes, potential design extensions and synergies with other projects.

astro-ph.IM↗
arXiv2023

Machine learning approach to the detection of point sources in maps of the CMB temperature anisotropies

We propose a machine learning approach to the blind detection of extragalactic point sources on maps of the temperature anisotropies of the cosmic microwave background. Using realistic simulations of the microwave sky as seen by Planck, we train a convolutional neural network (CNN) that solves source detection as an image segmentation problem. We divide the sky into regions of progressively increasing Galactic foreground intensity and independently train specialized CNNs for each region. This strategy leads to promising levels of completeness and reliability, with our CNN substantially outperforming traditional detection methods like the matched filter in regions close to the Galactic plane.

astro-ph.CO↗
arXiv2023

QUIJOTE scientific results -- VIII. Diffuse polarized foregrounds from component separation with QUIJOTE-MFI

We derive linearly polarized astrophysical component maps in the Northern Sky from the QUIJOTE-MFI data at 11 and 13 GHz in combination with the WMAP K and Ka bands (23 and 33 GHz) and all Planck polarized channels (30-353 GHz), using the parametric component separation method B-SeCRET. The addition of QUIJOTE-MFI data significantly improves the parameter estimation of the low-frequency foregrounds, especially the estimation of the synchrotron spectral index, $β_s$. We present the first detailed $β_s$ map of the Northern Celestial Hemisphere at a smoothing scale of $2^{\circ}$. We find statistically significant spatial variability across the sky. We obtain an average value of $-3.08$ and a dispersion of $0.13$, considering only pixels with reliable goodness-of-fit. The power law model of the synchrotron emission provides a good fit to the data outside the Galactic plane but fails to track the complexity within this region. Moreover, when we assume a synchrotron model with uniform curvature, $c_s$, we find a value of $c_s = -0.0797 \pm 0.0012$. However, there is insufficient statistical significance to determine which model is favoured, either the power law or the power law with uniform curvature. Furthermore, we estimate the thermal dust spectral parameters in polarization. Our CMB, synchrotron, and thermal dust maps are highly correlated with the corresponding products of the PR4 Planck release, although some large-scale differences are observed in the synchrotron emission. Finally, we find that the $β_s$ estimation in the high signal-to-noise synchrotron emission areas is prior-independent while, outside these regions, the prior governs the $β_s$ estimation.

astro-ph.CO↗
arXiv2023

QUIJOTE Scientific Results -- VII. Galactic AME sources in the QUIJOTE-MFI Northern Hemisphere Wide-Survey

The QUIJOTE-MFI Northern Hemisphere Wide-Survey has provided maps of the sky above declinations $-30^\circ$ at 11, 13, 17 and 19$\,$GHz. These data are combined with ancillary data to produce Spectral Energy Distributions in intensity in the frequency range 0.4--3\,000$\,$GHz on a sample of 52 candidate compact sources harbouring anomalous microwave emission (AME). We apply a component separation analysis at 1$^\circ$ scale on the full sample from which we identify 44 sources with high AME significance. We explore correlations between different fitted parameters on this last sample. QUIJOTE-MFI data contribute to notably improve the characterisation of the AME spectrum, and its separation from the other components. In particular, ignoring the 10--20\,GHz data produces on average an underestimation of the AME amplitude, and an overestimation of the free-free component. We find an average AME peak frequency of 23.6 $\pm$ 3.6$\,$GHz, about 4$\,$GHz lower than the value reported in previous studies. The strongest correlation is found between the peak flux density of the thermal dust and of the AME component. A mild correlation is found between the AME emissivity ($A_{\rm AME}/τ_{250}$) and the interstellar radiation field. On the other hand no correlation is found between the AME emissivity and the free-free radiation Emission Measure. Our statistical results suggest that the interstellar radiation field could still be the main driver of the intensity of the AME as regards spinning dust excitation mechanisms. On the other hand, it is not clear whether spinning dust would be most likely associated with cold phases of the interstellar medium rather than with hot phases dominated by free-free radiation.

astro-ph.GA↗
arXiv2023

QUIJOTE scientific results -- IV. A northern sky survey in intensity and polarization at 10-20GHz with the Multi-Frequency Instrument

We present QUIJOTE intensity and polarization maps in four frequency bands centred around 11, 13, 17 and 19GHz, and covering approximately 29000 deg$^2$, including most of the Northern sky region. These maps result from 9000 h of observations taken between May 2013 and June 2018 with the first QUIJOTE instrument (MFI), and have angular resolutions of around $1^\circ$, and sensitivities in polarization within the range 35-40 $μ$K per 1-degree beam, being a factor $\sim 2$-$4$ worse in intensity. We discuss the data processing pipeline employed, and the basic characteristics of the maps in terms of real space statistics and angular power spectra. A number of validation tests have been applied to characterise the accuracy of the calibration and the residual level of systematic effects, finding a conservative overall calibration uncertainty of 5%. We also discuss flux densities for four bright celestial sources (Tau A, Cas A, Cyg A and 3C274) which are often used as calibrators at microwave frequencies. The polarization signal in our maps is dominated by synchrotron emission. The distribution of spectral index values between the 11GHz and WMAP 23GHz map peaks at $β=-3.09$ with a standard deviation of 0.14. The measured BB/EE ratio at scales of $\ell=80$ is $0.26\pm 0.07$ for a Galactic cut $|b|>10^\circ$. We find a positive TE correlation for 11GHz at large angular scales ($\ell \lesssim 50$), while the EB and TB signals are consistent with zero in the multipole range $30 \lesssim \ell \lesssim 150$. The maps discussed in this paper are publicly available.

astro-ph.GA↗
arXiv2023

QUIJOTE scientific results -- VI. The Haze as seen by QUIJOTE

The Haze is an excess of microwave intensity emission surrounding the Galactic centre. It is spatially correlated with the $γ$-ray Fermi bubbles, and with the S-PASS radio polarization plumes, suggesting a possible common provenance. The models proposed to explain the origin of the Haze, including energetic events at the Galactic centre and dark matter decay in the Galactic halo, do not yet provide a clear physical interpretation. In this paper we present a re-analysis of the Haze including new observations from the Multi-Frequency Instrument (MFI) of the Q-U-I JOint TEnerife (QUIJOTE) experiment, at 11 and 13 GHz. We analyze the Haze in intensity and polarization, characterizing its spectrum. We detect an excess of diffuse intensity signal ascribed to the Haze. The spectrum at frequencies 11$\,\leqν\leq\,$70 GHz is a power-law with spectral index $β^{\rm H}=-2.79\pm0.08$, which is flatter than the Galactic synchrotron in the same region ($β^{\rm S}=-2.98\pm0.04$), but steeper than that obtained from previous works ($β^{\rm H}\sim-2.5$ at 23$\,\leq\,ν\leq\,$70 GHz). We also observe an excess of polarized signal in the QUIJOTE-MFI maps in the Haze area. This is a first hint detection of polarized Haze, or a consequence of curvature of the synchrotron spectrum in that area. Finally, we show that the spectrum of polarized structures associated with Galactic centre activity is steep at low frequencies ($β\sim -3.2$ at 2.3 $\leqν\leq$ 23 GHz), and becomes flatter above 11 GHz.

astro-ph.HE↗
arXiv2023

QUIJOTE scientific results -- V. The microwave intensity and polarisation spectra of the Galactic regions W49, W51 and IC443

We present new intensity and polarisation maps obtained with the QUIJOTE experiment towards the Galactic regions W49, W51 and IC443, covering the frequency range from 10 to 20 GHz at $\sim$ 1 deg angular resolution, with a sensitivity in the range 35-79 $μ$K/beam for total intensity and 13-23 $μ$K/beam for polarisation. For each region, we combine QUIJOTE maps with ancillary data at frequencies ranging from 0.4 to 3000 GHz, reconstruct the spectral energy distribution and model it with a combination of known foregrounds. We detect anomalous microwave emission (AME) in total intensity towards W49 at 4.7$σ$ and W51 at 4.0$σ$ with peak frequencies $ν_{AME}$ = (20.0 $\pm$ 1.4) GHz and $ν_{AME}$ = (17.7 $\pm$ 3.6) GHz respectively; this is the first detection of AME towards W51. The contamination from ultra-compact HII regions to the residual AME flux density is estimated at 10% in W49 and 5% in W51, and does not rule out the AME detection. The polarised SEDs reveal a synchrotron contribution with spectral indices $α_s$ = -0.67 $\pm$ 0.10 in W49 and $α_s$ = -0.51 $\pm$ 0.07 in W51, ascribed to the diffuse Galactic emission and to the local supernova remnant respectively. Towards IC443 in total intensity we measure a broken power-law synchrotron spectrum with cut-off frequency $ν_{0,s}$ = (114 $\pm$ 73) GHz, in agreement with previous studies; our analysis, however, rules out any AME contribution which had been previously claimed towards IC443. No evidence of polarised AME emission is detected in this study.

astro-ph.GA↗
arXiv2023

QUIJOTE scientific results -- IX. Radio sources in the QUIJOTE-MFI wide survey maps

We present the catalogue of Q-U-I JOint TEnerife (QUIJOTE) Wide Survey radio sources extracted from the maps of the Multi-Frequency Instrument compiled between 2012 and 2018. The catalogue contains 786 sources observed in intensity and polarization, and is divided into two separate sub-catalogues: one containing 47 bright sources previously studied by the \emph{Planck} collaboration and an extended catalogue of 739 sources either selected from the \emph{Planck} Second Catalogue of Compact Sources or found through a blind search carried out with a Mexican Hat 2 wavelet. A significant fraction of the sources in our catalogue (38.7 per cent) are within the $|b| \leq 20^\circ$ region of the Galactic plane. We determine statistical properties for those sources that are likely to be extragalactic. We find that these statistical properties are compatible with currently available models, with a $\sim$1.8 Jy completeness limit at 11 GHz. We provide the polarimetric properties of (38, 33, 31, 23) sources with P detected above the $99.99\%$ significance level at (11, 13, 17, 19) GHz, respectively. Median polarization fractions are in the $2.8$-$4.7$\% range in the 11-19 GHz frequency interval. We do not distinguish between Galactic and extragalactic sources here. The results presented here are consistent with those reported in the literature for flat- and steep-spectrum radio sources.

astro-ph.GA↗
arXiv2023

Robustness of cosmic birefringence measurement against Galactic foreground emission and instrumental systematics

The polarization of the cosmic microwave background (CMB) can be used to search for parity-violating processes like that predicted by a Chern-Simons coupling to a light pseudoscalar field. Such an interaction rotates $E$ modes into $B$ modes in the observed CMB signal by an effect known as cosmic birefringence. Even though isotropic birefringence can be confused with the rotation produced by a miscalibration of the detectors' polarization angles the degeneracy between both effects is broken when Galactic foreground emission is used as a calibrator. In this work, we use realistic simulations of the High-Frequency Instrument of the Planck mission to test the impact that Galactic foreground emission and instrumental systematics have on the recent birefringence measurements obtained through this technique. Our results demonstrate the robustness of the methodology against the miscalibration of polarization angles and other systematic effects, like intensity-to-polarization leakage, beam leakage, or cross-polarization effects. However, our estimator is sensitive to the $EB$ correlation of polarized foreground emission. Here we propose to correct the bias induced by dust $EB$ by modeling the foreground signal with templates produced in Bayesian component-separation analyses that fit parametric models to CMB data. Acknowledging the limitations of currently available dust templates like that of the Commander sky model, high-precision CMB data and a characterization of dust beyond the modified blackbody paradigm are needed to obtain a definitive measurement of cosmic birefringence in the future.

astro-ph.CO↗
arXiv2022

Improved limits on the tensor-to-scalar ratio using BICEP and Planck

We present constraints on the tensor-to-scalar ratio r using a combination of BICEP/Keck 2018 and Planck PR4 data allowing us to fit for r consistently with the six parameters of the $Λ$CDM model without fixing any of them. In particular, we are able to derive a constraint on the reionization optical depth $τ$ and thus propagate its uncertainty onto the posterior distribution for r. While Planck sensitivity to r is no longer comparable with ground-based measurements, combining Planck with BK18 and BAO gives results consistent with r = 0 and tightens the constraint to r < 0.032.

astro-ph.CO↗
arXiv2022

Polarization angle requirements for CMB B-mode experiments. Application to the LiteBIRD satellite

A methodology to provide the polarization angle requirements for different sets of detectors, at a given frequency of a CMB polarization experiment, is presented. The uncertainties in the polarization angle of each detector set are related to a given bias on the tensor-to-scalar ratio $r$ parameter. The approach is grounded in using a linear combination of the detector sets to obtain the CMB polarization signal. In addition, assuming that the uncertainties on the polarization angle are in the small angle limit (lower than a few degrees), it is possible to derive analytic expressions to establish the requirements. The methodology also accounts for possible correlations among detectors, that may originate from the optics, wafers, etc. The approach is applied to the LiteBIRD space mission. We show that, for the most restrictive case (i.e., full correlation of the polarization angle systematics among detector sets), the requirements on the polarization angle uncertainties are of around 1 arcmin at the most sensitive frequency bands (i.e., $\approx 150$ GHz) and of few tens of arcmin at the lowest (i.e., $\approx 40$ GHz) and highest (i.e., $\approx 400$ GHz) observational bands. Conversely, for the least restrictive case (i.e., no correlation of the polarization angle systematics among detector sets), the requirements are $\approx 5$ times less restrictive than for the previous scenario. At the global and the telescope levels, polarization angle knowledge of a few arcmins is sufficient for correlated global systematic errors and can be relaxed by a factor of two for fully uncorrelated errors in detector polarization angle. The reported uncertainty levels are needed in order to have the bias on $r$ due to systematics below the limit established by the LiteBIRD collaboration.

astro-ph.CO↗
arXiv2022

Characterization of the polarized synchrotron emission from Planck and WMAP data

The purpose of this work is to characterize the diffuse Galactic polarized synchrotron. We present EE, BB, and EB power spectra estimated cross-correlating Planck and WMAP polarization frequency maps at 23 and 30 GHz, for a set of six sky regions covering from 30% to 94% of the sky. The EE and BB angular power spectra show a steep decay of the spectral amplitude as a function of multipole, approximated by a power law with power indices around -2.9 for both components. The B/E ratio is about 0.22. The EB cross-component is compatible with zero at 1$σ$, with upper constraint on the EB/EE ratio of 1.2% at the 2$σ$ level. The recovered SED, in the frequency range 23-30 GHz, shows E and B power-law spectral indices compatible between themselves with a value of about -3.

astro-ph.CO↗
arXiv2022

Cosmic Birefringence from Planck Public Release 4

We search for the signature of parity-violating physics in the Cosmic Microwave Background using Planck polarization data from the Public Release 4 (PR4 or $\mathtt{NPIPE}$). For nearly full-sky data, we initially find a birefringence angle $β=0.30^\circ\pm0.11^\circ$ ($68\%$~C.L.). We also find that the values of $β$ decrease as we enlarge the Galactic mask, which can be interpreted as the effect of polarized foreground emission. We use two independent approaches to model this effect and mitigate its impact on $β$. Although results are promising, and the good agreement between both models is encouraging, we do not assign cosmological significance to the measured value of $β$ until we improve our knowledge of the foreground polarization. Acknowledging that the miscalibration of polarization angles is not the only instrumental systematic that can create spurious TB and EB correlations, we also perform a detailed study of $\mathtt{NPIPE}$ end-to-end simulations to prove that our measurements of $β$ are not significantly affected by any of the known systematics.

astro-ph.CO↗
arXiv2022

Characterization of the polarized synchrotron emission from Planck and WMAP data

The purpose of this work is to characterize the diffuse Galactic polarized synchrotron, which is the dominant CMB foreground emission at low frequency. We present EE, BB, and EB power spectra estimated from polarization frequency maps at 23 and 30 GHz as observed respectively by the WMAP K-band and the Planck lowest frequency channel, for a set of six sky regions covering from 30% to 94% of the sky. We study the synchrotron polarization angular distribution and spectral energy distribution (SED) by means of the so-called pseudo-$C_\ell$ formalism, provided by the NaMaster package, in the multipole interval 30 $\leq$ $\ell$ $\leq$ 300. Best results are obtained cross-correlating Planck and WMAP data. The EE and BB angular power spectra show a steep decay of the spectral amplitude as a function of multipole, approximated by a power law $C^{EE,BB} \propto \ell^{α_{EE,BB}}$, with $α_{EE}= -2.95\pm0.04$ and $α_{BB}=-2.85\pm0.14$. The B/E power asymmetry is proved with a B-to-E ratio, computed as the amplitude ratio at the pivot multipole $\ell = 80$, of 0.22$\pm$0.02. The EB cross-component is compatible with zero at 1$σ$, with an upper constraint on the EB/EE ratio of 1.2% at the 2$σ$ level. We show that the EE and BB power-law model with null EB cross-correlation describes reasonably well the diffuse synchrotron polarization emission for the full sky if the bright Galactic center and point sources are masked. The recovered SED shows power-law spectral indices $β_{EE}= -3.00 \pm 0.10$ and $β_{BB} = -3.05\pm0.36$ compatible between themselves, in the frequency range 23-30 GHz. Results also seem to indicate that the SED gets steeper from low to high Galactic latitude.

astro-ph.CO↗
arXiv2022

Cosmic Birefringence from Planck Data Release 4

We search for the signature of parity-violating physics in the cosmic microwave background, called cosmic birefringence, using the Planck data release 4. We initially find a birefringence angle of $β=0.30\pm0.11$ (68% C.L.) for nearly full-sky data. The values of $β$ decrease as we enlarge the Galactic mask, which can be interpreted as the effect of polarized foreground emission. Two independent ways to model this effect are used to mitigate the systematic impact on $β$ for different sky fractions. We choose not to assign cosmological significance to the measured value of $β$ until we improve our knowledge of the foreground polarization.

astro-ph.CO↗