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The Andromeda Galaxy (M31) is the Local Group galaxy that is most similar to the Milky Way (MW). The similarities between the two galaxies make M31 useful for studying integrated properties common to spiral galaxies. We use the data from the recent QUIJOTE-MFI Wide Survey, together with new raster observations focused on M31, to study its integrated emission. The addition of raster data improves the sensitivity of QUIJOTE-MFI maps by almost a factor 3. Our main interest is to confirm if anomalous microwave emission (AME) is present in M31, as previous studies have suggested. To do so, we built the integrated spectral energy distribution of M31 between 0.408 and 3000 GHz. We then performed a component separation analysis taking into account synchrotron, free–free, AME, and thermal dust components. AME in M31 is modelled as a log-normal distribution with maximum amplitude, A AME, equal to 1.03 ± 0.32 Jy. It peaks at |${\nu _{\rm AME}}=17.2\pm 3.2{\rm \, GHz}{}$| with a width of W AME = 0.58 ± 0.16. Both the Akaike and Bayesian information criteria find the model without AME to be less than 1 per cent as probable as the one taking AME into consideration. We find that the AME emissivity per 100  |$\mu$| m intensity in M31 is |${\epsilon _{\rm AME}^{\rm 28.4\, GHz}}=9.6\pm 3.1\,\mu$| K MJy−1 sr, similar to that of the MW. We also provide the first upper limits for the AME polarization fraction in an extragalactic object. M31 remains the only galaxy where an AME measurement has been made of its integrated spectrum. [ABSTRACT FROM AUTHOR]

We use the new QUIJOTE-MFI wide survey (11, 13, 17, and 19 GHz) to produce spectral energy distributions (SEDs), on an angular scale of 1°, of the supernova remnants (SNRs) CTB 80, Cygnus Loop, HB 21, CTA 1, Tycho, and HB 9. We provide new measurements of the polarized synchrotron radiation in the microwave range. The intensity and polarization SEDs are obtained and modelled by combining QUIJOTE-MFI maps with ancillary data. In intensity, we confirm the curved spectra of CTB 80 and HB 21 with a break frequency νb at 2.0 |$^{+1.2}_{-0.5}$| and 5.0 |$^{+1.2}_{-1.0}$|  GHz, respectively; and spectral indices above the break of |$-0.6^{+0.04}_{-0.05}$| and |$-0.86^{+0.04}_{-0.05}$|⁠. We provide constraints on the Anomalous Microwave Emission, suggesting that it is negligible towards these SNRs. From a simultaneous intensity and polarization fit, we recover synchrotron spectral indices as flat as −0.24, and the whole sample has a mean and scatter of −0.44 ± 0.12. The polarization fractions have a mean and scatter of 6.1 ± 1.9 per cent. When combining our results with the measurements from other QUIJOTE (Q-U-I JOint TEnerife CMB experiment) studies of SNRs, we find that radio spectral indices are flatter for mature SNRs, and particularly flatter for CTB 80 (⁠|$-0.24^{+0.07}_{-0.06}$|⁠) and HB 21 (⁠|$-0.34^{+0.04}_{-0.03}$|⁠). In addition, the evolution of the spectral indices against the SNRs age is modelled with a power-law function, providing an exponent −0.07 ± 0.03 and amplitude −0.49 ± 0.02 (at 10 kyr), which are conservative with respect to previous studies of our Galaxy and the Large Magellanic Cloud. [ABSTRACT FROM AUTHOR]

Anomalous microwave emission (AME) is an important emission component between 10 and 60 GHz that is not yet fully understood. It seems to be ubiquitous in our Galaxy and is observed at a broad range of angular scales. Here we use the new QUIJOTE-MFI wide survey data at 11, 13, 17, and 19 GHz to constrain the AME in the Galactic plane (| b | < 10°) on degree scales. We built the spectral energy distribution between 0.408 and 3000 GHz for each of the 5309 0.9° pixels in the Galactic plane, and fitted a parametric model by considering five emission components: synchrotron, free–free, AME, thermal dust and CMB anisotropies. We show that not including QUIJOTE-MFI data points leads to the underestimation (up to 50 per cent) of the AME signal in favour of free–free emission. The parameters describing these components are then intercompared, looking for relations that help to understand AME physical processes. We find median values for the AME width, W AME, and for its peak frequency, νAME, respectively of |$0.560^{+0.059}_{-0.050}$| and |$20.7^{+2.0}_{-1.9}$|  GHz, slightly in tension with current theoretical models. We find spatial variations throughout the Galactic plane for νAME, but only with reduced statistical significance. We report correlations of AME parameters with certain ISM properties, such as that between the AME emissivity (which shows variations with the Galactic longitude) and the interstellar radiation field, and that between the AME peak frequency and dust temperature. Finally, we discuss the implications of our results on the possible molecules responsible for AME. [ABSTRACT FROM AUTHOR]

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 Planck collaboration and an extended catalogue of 739 sources either selected from the 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 | ≤ 20° 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 ∼1.8 Jy completeness limit at 11 GHz. We provide the polarimetric properties of (38, 33, 31, 23) sources with P detected above the |$99.99{{\ \rm per\, cent}}$| significance level at (11, 13, 17, 19) GHz respectively. Median polarization fractions are in the 2.8–4.7 per cent 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. [ABSTRACT FROM AUTHOR]

We present new intensity and polarization maps obtained with the QUIJOTE experiment towards the Galactic regions W49, W51 and IC443, covering the frequency range from 10 to 20 GHz at |$\sim 1\, \text{deg}$| angular resolution, with a sensitivity in the range 35–79  |$\mu \text{K}\, \text{beam}^{-1}$| for total intensity and 13–23  |$\mu \text{K}\, \text{beam}^{-1}$| for polarization. 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 4.7σ and W51 at 4.0σ with peak frequencies |$\nu _{\rm AME}=(20.0\pm 1.4)\, \text{GHz}$| and |$\nu _{\rm AME}=(17.7\pm 3.6)\, \text{GHz}$|⁠ , respectively; this is the first detection of AME towards W51. The contamination from ultracompact H  ii regions to the residual AME flux density is estimated at 10 per cent in W49 and 5 per cent in W51, and does not rule out the AME detection. The polarized SEDs reveal a synchrotron contribution with spectral indices αs = −0.67 ± 0.10 in W49 and αs = −0.51 ± 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 |$\nu _{\rm 0,s}=(114\pm 73)\, \text{GHz}$|⁠ , in agreement with previous studies; our analysis, however, rules out any AME contribution which had been previously claimed towards IC443. No evidence of polarized AME emission is detected in this study. [ABSTRACT FROM AUTHOR]

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 reanalysis 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 analyse 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 GHz |$\, \le \nu \le \,$| 70 GHz is a power law with spectral index βH = −2.79 ± 0.08, which is flatter than the Galactic synchrotron in the same region (βS = −2.98 ± 0.04), but steeper than that obtained from previous works (βH ∼ −2.5 at 23 GHz |$\, \le \, \nu \le \,$| 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 ∼ −3.2 at 2.3 GHz ≤ ν ≤ 23 GHz), and becomes flatter above 11 GHz. [ABSTRACT FROM AUTHOR]

We present QUIJOTE intensity and polarization maps in four frequency bands centred around 11, 13, 17, and 19 GHz, and covering approximately 29 000 deg2, 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 multifrequency instrument (MFI), and have angular resolutions of around 1°, and sensitivities in polarization within the range 35–40 µK per 1° beam, being a factor ∼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 characterize the accuracy of the calibration and the residual level of systematic effects, finding a conservative overall calibration uncertainty of 5 per cent. 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 11 GHz and WMAP 23 GHz map peaks at β = −3.09 with a standard deviation of 0.14. The measured BB/EE ratio at scales of ℓ = 80 is 0.26 ± 0.07 for a Galactic cut | b | > 10°. We find a positive TE correlation for 11 GHz at large angular scales (ℓ ≲ 50), while the EB and TB signals are consistent with zero in the multipole range 30 ≲ ℓ ≲ 150. The maps discussed in this paper are publicly available. [ABSTRACT FROM AUTHOR]

The QUIJOTE-MFI Northern Hemisphere Wide Survey has provided maps of the sky above declinations −30° 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° 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 characterization 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 ± 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 AME/τ250) 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. [ABSTRACT FROM AUTHOR]

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 Wilkinson Microwave Anisotropy Probe 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, βs. We present the first detailed βs map of the Northern Celestial Hemisphere at a smoothing scale of 2°. 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 ± 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 cosmic microwave background, 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 βs estimation in the high signal-to-noise synchrotron emission areas is prior-independent, while, outside these regions, the prior governs the βs estimation. [ABSTRACT FROM AUTHOR]

Map-making is an important step for the data analysis of cosmic microwave background (CMB) experiments. It consists of converting the data, which are typically a long, complex, and noisy collection of measurements, into a map, which is an image of the observed sky. We present in this paper a new map-making code named picasso (Polarization and Intensity CArtographer for Scanned Sky Observations), which was implemented to construct intensity and polarization maps from the Multi Frequency Instrument (MFI) of the QUIJOTE (Q-U-I Joint TEnerife) CMB polarization experiment. picasso is based on the destriping algorithm, and is suited to address specific issues of ground-based microwave observations, with a technique that allows the fit of a template function in the time domain, during the map-making step. This paper describes the picasso code, validating it with simulations and assessing its performance. For this purpose, we produced realistic simulations of the QUIJOTE-MFI survey of the northern sky (approximately ∼20 000 deg2), and analysed the reconstructed maps with picasso , using real and harmonic space statistics. We show that, for this sky area, picasso is able to reconstruct, with high fidelity, the injected signal, recovering all the scales with ℓ > 10 in TT, EE, and BB. The signal error is better than 0.001 per cent at 20 < ℓ < 200. Finally, we validated some of the methods that will be applied to the real wide-survey data, like the detection of the CMB anisotropies via cross-correlation analyses. Despite that the implementation of picasso is specific for QUIJOTE-MFI data, it could be adapted to other experiments. [ABSTRACT FROM AUTHOR]

Anomalous Microwave Emission (AME) is a significant component of Galactic diffuse emission in the frequency range 10– |$60\, \mathrm{GHz}$| and a new window into the properties of sub-nanometre-sized grains in the interstellar medium. We investigate the morphology of AME in the ≈10○ diameter λ Orionis ring by combining intensity data from the QUIJOTE experiment at 11, 13, 17, and |$19\, \mathrm{GHz}$| and the C-Band All Sky Survey (C-BASS) at |$4.76\, \mathrm{GHz}$|⁠ , together with 19 ancillary data sets between 1.42 and |$3000\, \mathrm{GHz}$|⁠. Maps of physical parameters at 1○ resolution are produced through Markov chain Monte Carlo (MCMC) fits of spectral energy distributions (SEDs), approximating the AME component with a lognormal distribution. AME is detected in excess of |$20\, \sigma$| at degree-scales around the entirety of the ring along photodissociation regions (PDRs), with three primary bright regions containing dark clouds. A radial decrease is observed in the AME peak frequency from |$\approx 35\, \mathrm{GHz}$| near the free–free region to |$\approx 21\, \mathrm{GHz}$| in the outer regions of the ring, which is the first detection of AME spectral variations across a single region. A strong correlation between AME peak frequency, emission measure and dust temperature is an indication for the dependence of the AME peak frequency on the local radiation field. The AME amplitude normalized by the optical depth is also strongly correlated with the radiation field, giving an overall picture consistent with spinning dust where the local radiation field plays a key role. [ABSTRACT FROM AUTHOR]

We present new intensity and polarization observations of the Taurus Molecular Cloud (TMC) region in the frequency range 10–20 GHz with the multifrequency instrument (MFI) mounted on the first telescope of the Q-U-I-JOint TEnerife (QUIJOTE) experiment. From the combination of the QUIJOTE data with the WMAP 9-yr data release, the Planck second data release, the DIRBE maps, and ancillary data, we detect an anomalous microwave emission (AME) component with flux density |$S_{\rm AME, peak} = 43.0 \pm 7.9\,$|  Jy in the TMC and |$S_{\rm AME, peak} = 10.7 \pm 2.7\,$|  Jy in the dark cloud nebula L1527, which is part of the TMC. In the TMC the diffuse AME emission peaks around a frequency of 19 GHz, compared with an emission peak about a frequency of 25 GHz in L1527. In the TMC, the best constraint on the level of AME polarization is obtained at the Planck channel of 28.4 GHz, with an upper limit |$\pi _{\rm AME}\lt 4.2\, {{\ \rm per\ cent}}$| (95  |$\, {{\ \rm per\ cent}}$| C.L.), which reduces to |$\pi _{\rm AME}\lt 3.8\, {{\ \rm per\ cent}}$| (95 |$\, {{\ \rm per\ cent}}$| C.L.) if the intensity of all the free–free, synchrotron and thermal dust components are negligible at this frequency. The same analysis in L1527 leads to |$\pi _{\rm AME}\lt 5.3{{\ \rm per\ cent}}$| (95 |$\, {{\ \rm per\ cent}}$| C.L.) or |$\pi _{\rm AME}\lt 4.5\, {{\ \rm per\ cent}}$| (95 |${{\ \rm per\ cent}}$| C.L.) under the same assumption. We find that in the TMC and L1527 on average about |$80{{\ \rm per\ cent}}$| of the H  ii gas should be mixed with thermal dust. Our analysis shows how the QUIJOTE-MFI 10–20 GHz data provide key information to properly separate the synchrotron, free–free, and AME components. [ABSTRACT FROM AUTHOR]

In this paper, we present Q-U-I JOint Tenerife Experiment (QUIJOTE) 10–20 GHz observations (194 h in total over ≈250 deg²) in intensity and polarisation of G159.6-18.5, one of the most widely studied regions harbouring anomalous microwave emission (AME). By combining with other publicly available intensity data, we achieve the most precise spectrum of the AME measured to date in an individual region, with 13 independent data points between 10 and 50 GHz being dominated by this emission. The four QUIJOTE data points provide the first independent confirmation of the downturn of the AME spectrum at low frequencies, initially unveiled by the COSMOlogical Structures On Medium Angular Scales experiment in this region. Our polarisation maps, which have an angular resolution of ≈1° and a sensitivity of ≈ 25 μK beam−1, are consistent with zero polarisation. We obtain upper limits on the polarisation fraction of Π < 6.3 and <2.8 percent (95 percent C.L.), respectively, at 12 and 18 GHz (ΠAME < 10.1 and <3.4 percent with respect to the residual AME intensity), a frequency range where no AME polarisation observations have been reported to date. The combination of these constraints with those from other experiments confirm that all the magnetic dust models based on single-domain grains, and most of those considering randomly oriented magnetic inclusions, predict higher polarisation levels than is observed towards regions with AME. Also, neither of the two considered models of electric dipole emission seems to be compatible with all the observations together. More stringent constraints of the AME polarisation at 10–40 GHz are necessary to disentangle between different models, to which future QUIJOTE data will contribute. [ABSTRACT FROM AUTHOR]

We present a method for fast optimal estimation of the temperature angular power spectrum from observations of the cosmic microwave background. We employ a Hamiltonian Monte Carlo (HMC) sampler to obtain samples from the posterior probability distribution of all the power spectrum coefficients given a set of observations. We compare the properties of the HMC and the related Gibbs sampling approach on low-resolution simulations. The correlation lengths of the samples produced by Gibbs and HMC are generally comparable. At very high signal-to-noise (≳10) the Gibbs outperforms the HMC while for intermediate signal-to-noise (∼0.1–10) the HMC results in shorter correlation lengths than the Gibbs. At low signal-to-noise (≲0.1) both samplers appear to perform similarly. We also demonstrate the method on high-resolution data by applying it to simulated Wilkinson Microwave Anisotropy Probe ( WMAP) data. Analysis of a single map from a WMAP-resolution data set is possible in around 80 h on a high-end desktop computer. HMC uses around a factor of 3–4 fewer spherical harmonic transforms than is reported for a Gibbs sampler (with pre-conditioning) and therefore produces noticeable performance gains. HMC imposes few conditions on the distribution to be sampled and obviates the requirement of having to be able to sample efficiently from the conditional densities, thus providing us with an extremely flexible approach upon which to build. [ABSTRACT FROM AUTHOR]

A harmonic-space maximum-entropy method (MEM) is presented for separating the emission from different physical components in all-sky observations by the forthcoming Planck satellite. The analysis is performed at full Planck resolution, with a pixel size of 1.7 arcmin, which l[SUBmax] ≈ 6000. The simulated Planck data include emission from the cosmic microwave background (CMB), the kinetic and thermal Sunyaev-Zel'dovich (SZ) effects from galaxy clusters, as well as Galactic dust, free-free and synchrotron emission. Our simulations also assume homogeneous, uncorrelated pixel noise, although this is not a requirement of the method. We rind that the MEM technique produces faithful reconstructions of the main input components over the whole sky, without the need to perform a Galactic cut. The CMB power spectrum is accurately recovered up to l ≈ 2000. The algorithm is parallelized so that the entire reconstruction can be performed in ~6 h using 30 R10000 processors on an SGI Origin 2000 supercomputer and requires 14 Gb of RAM. [ABSTRACT FROM AUTHOR]

We present a harmonic model for the data analysis of an all-sky cosmic microwave background survey, such as Planck, where the survey is obtained through ring-scans of the sky. In this model, resampling and pixelization of the data are avoided. The spherical transforms of the sky at each frequency, in total intensity and polarization, as well as the bright-point-source catalogue, are derived directly from the data reduced on to the rings. Formal errors and the most significant correlation coefficients for the spherical transforms of the frequency maps are preserved. A clean and transparent path from the original samplings in the time domain to the final scientific products is thus obtained. The data analysis is largely based on Fourier analysis of rings; the positional stability of the instrument's spin axis during these scans is a requirement for the data model and is investigated here for the Planck satellite. Brighter point sources are recognized and extracted as part of the ring reductions and, on the basis of accumulated data, used to build the bright-point-source catalogue. The analysis of the rings is performed in an iterative loop, involving a range of geometric and detector response calibrations. The geometric calibrations are used to reconstruct the paths of the detectors over the sky during a scan and the phase offsets between scans of different detectors; the response calibrations eliminate short- and long-term variations in detector response. Point-source information may allow the reconstruction of the beam profile. The reconstructed spherical transforms of the sky in each frequency channel form the input to the subsequent analysis stages. Although the methods in this paper were developed with the data processing for the Planck satellite in mind, there are many aspects which have wider implementation possibilities, including the construction of real-space pixelized maps. [ABSTRACT FROM AUTHOR]