21. 
 Aghanim, N., et al.
(författare)

Planck intermediate results XLIV. Structure of the Galactic magnetic field from dust polarization maps of the southern Galactic cap
 2016

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 596

Tidskriftsartikel (refereegranskat)abstract
 Using data from the Planck satellite, we study the statistical properties of interstellar dust polarization at high Galactic latitudes around the south pole (b < 60 degrees). Our aim is to advance the understanding of the magnetized interstellar medium (ISM), and to provide a modelling framework of the polarized dust foreground for use in cosmic microwave background (CMB) componentseparation procedures. We examine the Stokes I, Q, and U maps at 353 GHz, and particularly the statistical distribution of the polarization fraction (p) and angle (Psi), in order to characterize the ordered and turbulent components of the Galactic magnetic field (GMF) in the solar neighbourhood. The Q and U maps show patterns at large angular scales, which we relate to the mean orientation of the GMF towards Galactic coordinates (l(0); b(0)) = (70 degrees +/ 5 degrees, 24 degrees +/ 5 degrees). The histogram of the observed p values shows a wide dispersion up to 25%. The histogram Psi of has a standard deviation of 12 degrees about the regular pattern expected from the ordered GMF. We build a phenomenological model that connects the distributions of p and Psi to a statistical description of the turbulent component of the GMF, assuming a uniform effective polarization fraction (p(0)) of dust emission. To compute the Stokes parameters, we approximate the integration along the line of sight (LOS) as a sum over a set of N independent polarization layers, in each of which the turbulent component of the GMF is obtained from Gaussian realizations of a powerlaw power spectrum. We are able to reproduce the observed p and distributions using a p0 value of 26%, a ratio of 0.9 between the strengths of the turbulent and mean components of the GMF, and a small value of N. The mean value of p (inferred from the fit of the largescale patterns in the Stokes maps) is 12 +/ 1%. We relate the polarization layers to the density structure and to the correlation length of the GMF along the LOS. We emphasize the simplicity of our model (involving only a few parameters), which can be easily computed on the celestial sphere to produce simulated maps of dust polarization. Our work is an important step towards a model that can be used to assess the accuracy of componentseparation methods in present and future CMB experiments designed to search the B mode CMB polarization from primordial gravity waves.


22. 
 Aghanim, N., et al.
(författare)

Planck intermediate results XLVI. Reduction of largescale systematic effects in HFI polarization maps and estimation of the reionization optical depth
 2016

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 596

Tidskriftsartikel (refereegranskat)abstract
 This paper describes the identification, modelling, and removal of previously unexplained systematic effects in the polarization data of the Planck High Frequency Instrument (HFI) on large angular scales, including new mapmaking and calibration procedures, new and more complete endtoend simulations, and a set of robust internal consistency checks on the resulting maps. These maps, at 100, 143, 217, and 353 GHz, are early versions of those that will be released in final form later in 2016. The improvements allow us to determine the cosmic reionization optical depth tau using, for the first time, the lowmultipole EE data from HFI, reducing significantly the central value and uncertainty, and hence the upper limit. Two different likelihood procedures are used to constrain tau from two estimators of the CMB E and Bmode angular power spectra at 100 and 143 GHz, after debiasing the spectra from a small remaining systematic contamination. These all give fully consistent results. A further consistency test is performed using crosscorrelations derived from the Low Frequency Instrument maps of the Planck 2015 data release and the new HFI data. For this purpose, endtoend analyses of systematic effects from the two instruments are used to demonstrate the near independence of their dominant systematic error residuals. The tightest result comes from the HFIbased tau posterior distribution using the maximum likelihood power spectrum estimator from EE data only, giving a value 0.055 +/ 0.009. In a companion paper these results are discussed in the context of the bestfit Planck Lambda CDM cosmological model and recent models of reionization.


23. 
 Aghanim, N., et al.
(författare)

Planck 2018 results V. CMB power spectra and likelihoods
 2020

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 641

Tidskriftsartikel (refereegranskat)abstract
 We describe the legacy Planck cosmic microwave background (CMB) likelihoods derived from the 2018 data release. The overall approach is similar in spirit to the one retained for the 2013 and 2015 data release, with a hybrid method using different approximations at low (l< 30) and high (l >= 30) multipoles, implementing several methodological and dataanalysis refinements compared to previous releases. With more realistic simulations, and better correction and modelling of systematic effects, we can now make full use of the CMB polarization observed in the High Frequency Instrument (HFI) channels. The lowmultipole EE crossspectra from the 100 GHz and 143 GHz data give a constraint on the Lambda CDM reionization opticaldepth parameter tau to better than 15% (in combination with the TT lowl data and the highl temperature and polarization data), tightening constraints on all parameters with posterior distributions correlated with tau. We also update the weaker constraint on tau from the joint TEB likelihood using the Low Frequency Instrument (LFI) channels, which was used in 2015 as part of our baseline analysis. At higher multipoles, the CMB temperature spectrum and likelihood are very similar to previous releases. A better model of the temperaturetopolarization leakage and corrections for the effective calibrations of the polarization channels (i.e., the polarization efficiencies) allow us to make full use of polarization spectra, improving the Lambda CDM constraints on the parameters theta(MC), omega(c), omega(b), and H0 by more than 30%, and n(s) by more than 20% compared to TTonly constraints. Extensive tests on the robustness of the modelling of the polarization data demonstrate good consistency, with some residual modelling uncertainties. At high multipoles, we are now limited mainly by the accuracy of the polarization efficiency modelling. Using our various tests, simulations, and comparison between different highmultipole likelihood implementations, we estimate the consistency of the results to be better than the 0.5 sigma level on the Lambda CDM parameters, as well as classical singleparameter extensions for the joint likelihood (to be compared to the 0.3 sigma levels we achieved in 2015 for the temperature data alone on Lambda CDM only). Minor curiosities already present in the previous releases remain, such as the differences between the bestfit Lambda CDM parameters for the l< 800 and l> 800 ranges of the power spectrum, or the preference for more smoothing of the powerspectrum peaks than predicted in Lambda CDM fits. These are shown to be driven by the temperature power spectrum and are not significantly modified by the inclusion of the polarization data. Overall, the legacy Planck CMB likelihoods provide a robust tool for constraining the cosmological model and represent a reference for future CMB observations.


24. 
 Aghanim, N., et al.
(författare)

Planck 2018 results VIII. Gravitational lensing
 2020

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 641

Tidskriftsartikel (refereegranskat)abstract
 We present measurements of the cosmic microwave background (CMB) lensing potential using the final Planck 2018 temperature and polarization data. Using polarization maps filtered to account for the noise anisotropy, we increase the significance of the detection of lensing in the polarization maps from 5 sigma to 9 sigma. Combined with temperature, lensing is detected at 40 sigma. We present an extensive set of tests of the robustness of the lensingpotential power spectrum, and construct a minimumvariance estimator likelihood over lensing multipoles 8 <= L <= 400 (extending the range to lower L compared to 2015), which we use to constrain cosmological parameters. We find good consistency between lensing constraints and the results from the Planck CMB power spectra within the Lambda CDM model. Combined with baryon density and other weak priors, the lensing analysis alone constrains (8)Omega (0.25)(m) = 0.589 +/ 0.020 sigma 8 Omega m 0.25 = 0.589 +/ 0.020 (1 sigma errors). Also combining with baryon acoustic oscillation data, we find tight individual parameter constraints, sigma (8)=0.811 +/ 0.019, H0 = 67.9(1.3)(+1.2) km s(1) Mpc(1) H 0 = 67 . 9  1.3 + 1.2 .> km s  1 . Mpc  1 , and Omega (m) = 0.303(0.018)(+0.016) Omega m = 0 . 303  0.018 + 0.016 . Combining with Planck CMB power spectrum data, we measure sigma (8) to better than 1% precision, finding sigma (8)=0.811 +/ 0.006. CMB lensing reconstruction data are complementary to galaxy lensing data at lower redshift, having a different degeneracy direction in sigma (8)Omega (m) space; we find consistency with the lensing results from the Dark Energy Survey, and give combined lensingonly parameter constraints that are tighter than joint results using galaxy clustering. Using the Planck cosmic infrared background (CIB) maps as an additional tracer of highredshift matter, we make a combined Planckonly estimate of the lensing potential over 60% of the sky with considerably more smallscale signal. We additionally demonstrate delensing of the Planck power spectra using the joint and individual lensing potential estimates, detecting a maximum removal of 40% of the lensinginduced power in all spectra. The improvement in the sharpening of the acoustic peaks by including both CIB and the quadratic lensing reconstruction is detected at high significance.


25. 
 Aghanim, N., et al.
(författare)

Planck intermediate results LI. Features in the cosmic microwave background temperature power spectrum and shifts in cosmological parameters
 2017

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 607

Tidskriftsartikel (refereegranskat)abstract
 The six parameters of the standard Lambda CDM model have bestfit values derived from the Planck temperature power spectrum that are shifted somewhat from the bestfit values derived from WMAP data. These shifts are driven by features in the Planck temperature power spectrum at angular scales that had never before been measured to cosmicvariance level precision. We have investigated these shifts to determine whether they are within the range of expectation and to understand their origin in the data. Taking our parameter set to be the optical depth of the reionized intergalactic medium tau, the baryon density omega(b), the matter density omega(m), the angular size of the sound horizon theta(*), the spectral index of the primordial power spectrum, n(s), and A(s)e(2 pi) (where As is the amplitude of the primordial power spectrum), we have examined the change in bestfit values between a WMAPlike large angularscale data set (with multipole moment l < 800 in the Planck temperature power spectrum) and an all angularscale data set (l < 2500 Planck temperature power spectrum), each with a prior on tau of 0.07 +/ 0.02. We find that the shifts, in units of the 1 sigma expected dispersion for each parameter, are {Delta tau, Delta A(s)e(2 tau), Delta n(s), Delta omega(m), Delta omega(b), Delta theta(*)} = {1.7, 2.2, 1.2, 2.0, 1.1, 0.9}, with a chi(2) value of 8.0. We find that this chi(2) value is exceeded in 15% of our simulated data sets, and that a parameter deviates by more than 2.2 sigma in 9% of simulated data sets, meaning that the shifts are not unusually large. Comparing l < 800 instead to l > 800, or splitting at a different multipole, yields similar results. We examined the l < 800 model residuals in the l > 800 power spectrum data and find that the features there that drive these shifts are a set of oscillations across a broad range of angular scales. Although they partly appear similar to the effects of enhanced gravitational lensing, the shifts in Lambda CDM parameters that arise in response to these features correspond to model spectrum changes that are predominantly due to nonlensing effects; the only exception is tau, which, at fixed A(s)e(2 tau), affects the l > 800 temperature power spectrum solely through the associated change in As and the impact of that on the lensing potential power spectrum. We also ask, what is it about the power spectrum at l < 800 that leads to somewhat different bestfit parameters than come from the full l range? We find that if we discard the data at l < 30, where there is a roughly 2 sigma downward fluctuation in power relative to the model that best fits the full l range, the l < 800 bestfit parameters shift significantly towards the l < 2500 bestfit parameters. In contrast, including l < 30, this previously noted lowl deficit drives ns up and impacts parameters correlated with ns, such as omega(m) and H0. As expected, the l < 30 data have a much greater impact on the l < 800 best fit than on the l < 2500 best fit. So although the shifts are not very significant, we find that they can be understood through the combined effects of an oscillatorylike set of highl residuals and the deficit in lowl power, excursions consistent with sample variance that happen to map onto changes in cosmological parameters. Finally, we examine agreement between Planck TT data and two other CMB data sets, namely the Planck lensing reconstruction and the TT power spectrum measured by the South Pole Telescope, again finding a lack of convincing evidence of any significant deviations in parameters, suggesting that current CMB data sets give an internally consistent picture of the Lambda CDM model.


26. 
 Aghanim, N., et al.
(författare)

Planck 2018 results I. Overview and the cosmological legacy of Planck
 2020

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 641

Tidskriftsartikel (refereegranskat)abstract
 The European Space Agency's Planck satellite, which was dedicated to studying the early Universe and its subsequent evolution, was launched on 14 May 2009. It scanned the microwave and submillimetre sky continuously between 12 August 2009 and 23 October 2013, producing deep, highresolution, allsky maps in nine frequency bands from 30 to 857 GHz. This paper presents the cosmological legacy of Planck, which currently provides our strongest constraints on the parameters of the standard cosmological model and some of the tightest limits available on deviations from that model. The 6parameter Lambda CDM model continues to provide an excellent fit to the cosmic microwave background data at high and low redshift, describing the cosmological information in over a billion map pixels with just six parameters. With 18 peaks in the temperature and polarization angular power spectra constrained well, Planck measures five of the six parameters to better than 1% (simultaneously), with the bestdetermined parameter (theta (*)) now known to 0.03%. We describe the multicomponent sky as seen by Planck, the success of the Lambda CDM model, and the connection to lowerredshift probes of structure formation. We also give a comprehensive summary of the major changes introduced in this 2018 release. The Planck data, alone and in combination with other probes, provide stringent constraints on our models of the early Universe and the largescale structure within which all astrophysical objects form and evolve. We discuss some lessons learned from the Planck mission, and highlight areas ripe for further experimental advances.


27. 
 Aghanim, N., et al.
(författare)

Planck 2018 results VI. Cosmological parameters
 2020

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 641

Tidskriftsartikel (refereegranskat)abstract
 We present cosmological parameter results from the final fullmission Planck measurements of the cosmic microwave background (CMB) anisotropies, combining information from the temperature and polarization maps and the lensing reconstruction. Compared to the 2015 results, improved measurements of largescale polarization allow the reionization optical depth to be measured with higher precision, leading to significant gains in the precision of other correlated parameters. Improved modelling of the smallscale polarization leads to more robust constraints on many parameters, with residual modelling uncertainties estimated to affect them only at the 0.5 sigma level. We find good consistency with the standard spatiallyflat 6parameter Lambda CDM cosmology having a powerlaw spectrum of adiabatic scalar perturbations (denoted base Lambda CDM in this paper), from polarization, temperature, and lensing, separately and in combination. A combined analysis gives dark matter density Omega (c)h(2)=0.120 +/ 0.001, baryon density Omega (b)h(2)=0.0224 +/ 0.0001, scalar spectral index n(s)=0.965 +/ 0.004, and optical depth tau =0.054 +/ 0.007 (in this abstract we quote 68% confidence regions on measured parameters and 95% on upper limits). The angular acoustic scale is measured to 0.03% precision, with 100 theta (*)=1.0411 +/ 0.0003. These results are only weakly dependent on the cosmological model and remain stable, with somewhat increased errors, in many commonly considered extensions. Assuming the baseLambda CDM cosmology, the inferred (modeldependent) lateUniverse parameters are: Hubble constant H0=(67.4 +/ 0.5) km s(1) Mpc(1); matter density parameter Omega (m)=0.315 +/ 0.007; and matter fluctuation amplitude sigma (8)=0.811 +/ 0.006. We find no compelling evidence for extensions to the baseLambda CDM model. Combining with baryon acoustic oscillation (BAO) measurements (and considering singleparameter extensions) we constrain the effective extra relativistic degrees of freedom to be Neff=2.99 +/ 0.17, in agreement with the Standard Model prediction Neff=3.046, and find that the neutrino mass is tightly constrained to Sigma m(nu)< 0.12 eV. The CMB spectra continue to prefer higher lensing amplitudes than predicted in base CDM at over 2 sigma, which pulls some parameters that affect the lensing amplitude away from the Lambda CDM model; however, this is not supported by the lensing reconstruction or (in models that also change the background geometry) BAO data. The joint constraint with BAO measurements on spatial curvature is consistent with a flat universe, Omega (K)=0.001 +/ 0.002. Also combining with Type Ia supernovae (SNe), the darkenergy equation of state parameter is measured to be w(0)=1.03 +/ 0.03, consistent with a cosmological constant. We find no evidence for deviations from a purely powerlaw primordial spectrum, and combining with data from BAO, BICEP2, and Keck Array data, we place a limit on the tensortoscalar ratio r(0.002)< 0.06. Standard bigbang nucleosynthesis predictions for the helium and deuterium abundances for the baseCDM cosmology are in excellent agreement with observations. The Planck baseLambda CDM results are in good agreement with BAO, SNe, and some galaxy lensing observations, but in slight tension with the Dark Energy Survey's combinedprobe results including galaxy clustering (which prefers lower fluctuation amplitudes or matter density parameters), and in significant, 3.6 sigma, tension with local measurements of the Hubble constant (which prefer a higher value). Simple model extensions that can partially resolve these tensions are not favoured by the Planck data.


28. 
 Aghanim, N., et al.
(författare)

Planck intermediate results XLVIII. Disentangling Galactic dust emission and cosmic infrared background anisotropies
 2016

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 596

Tidskriftsartikel (refereegranskat)abstract
 Using the Planck 2015 data release (PR2) temperature maps, we separate Galactic thermal dust emission from cosmic infrared background (CIB) anisotropies. For this purpose, we implement a specifically tailored componentseparation method, the socalled generalized needlet internal linear combination (GNILC) method, which uses spatial information (the angular power spectra) to disentangle the Galactic dust emission and CIB anisotropies. We produce significantly improved allsky maps of Planck thermal dust emission, with reduced CIB contamination, at 353, 545, and 857 GHz. By reducing the CIB contamination of the thermal dust maps, we provide more accurate estimates of the local dust temperature and dust spectral index over the sky with reduced dispersion, especially at high Galactic latitudes above b = +/ 20 degrees. We find that the dust temperature is T = (19.4 +/ 1.3) K and the dust spectral index is beta = 1.6 +/ 0.1 averaged over the whole sky, while T = (19.4 +/ 1.5) K and beta = 1.6 +/ 0.2 on 21% of the sky at high latitudes. Moreover, subtracting the new CIBremoved thermal dust maps from the CMBremoved Planck maps gives access to the CIB anisotropies over 60% of the sky at Galactic latitudes vertical bar b vertical bar > 20 degrees. Because they are a significant improvement over previous Planck products, the GNILC maps are recommended for thermal dust science. The new CIB maps can be regarded as indirect tracers of the dark matter and they are recommended for exploring crosscorrelations with lensing and largescale structure optical surveys. The reconstructed GNILC thermal dust and CIB maps are delivered as Planck products.


29. 
 Akrami, Y., et al.
(författare)

Planck 2018 results IV. Diffuse component separation
 2020

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 641

Tidskriftsartikel (refereegranskat)abstract
 We present fullsky maps of the cosmic microwave background (CMB) and polarized synchrotron and thermal dust emission, derived from the third set of Planck frequency maps. These products have significantly lower contamination from instrumental systematic effects than previous versions. The methodologies used to derive these maps follow closely those described in earlier papers, adopting four methods (Commander, NILC, SEVEM, and SMICA) to extract the CMB component, as well as three methods (Commander, GNILC, and SMICA) to extract astrophysical components. Our revised CMB temperature maps agree with corresponding products in the Planck 2015 delivery, whereas the polarization maps exhibit significantly lower largescale power, reflecting the improved data processing described in companion papers; however, the noise properties of the resulting data products are complicated, and the best available endtoend simulations exhibit relative biases with respect to the data at the few percent level. Using these maps, we are for the first time able to fit the spectral index of thermal dust independently over 3 degrees regions. We derive a conservative estimate of the mean spectral index of polarized thermal dust emission of beta (d)=1.55 +/ 0.05, where the uncertainty marginalizes both over all known systematic uncertainties and different estimation techniques. For polarized synchrotron emission, we find a mean spectral index of beta (s)=3.1 +/ 0.1, consistent with previously reported measurements. We note that the current data processing does not allow for construction of unbiased singlebolometer maps, and this limits our ability to extract CO emission and correlated components. The foreground results for intensity derived in this paper therefore do not supersede corresponding Planck 2015 products. For polarization the new results supersede the corresponding 2015 products in all respects.


30. 
 Akrami, Y., et al.
(författare)

Planck 2018 results IX. Constraints on primordial nonGaussianity
 2020

Ingår i: Astronomy and Astrophysics.  : EDP Sciences.  00046361 . 14320746. ; 641

Tidskriftsartikel (refereegranskat)abstract
 We analyse the Planck fullmission cosmic microwave background (CMB) temperature and Emode polarization maps to obtain constraints on primordial nonGaussianity (NG). We compare estimates obtained from separable templatefitting, binned, and optimal modal bispectrum estimators, finding consistent values for the local, equilateral, and orthogonal bispectrum amplitudes. Our combined temperature and polarization analysis produces the following final results: (local)(NL) = 0.9 +/ 5.1 f NL local =  0.9 +/ 5.1 ; f(NL)(equil) = 26 +/ 47 f NL equil =  26 +/ 47 ; and f(NL)(ortho) = 38 +/ 24 f NL ortho =  38 +/ 24 (68% CL, statistical). These results include lowmultipole (4 <= l< 40) polarization data that are not included in our previous analysis. The results also pass an extensive battery of tests (with additional tests regarding foreground residuals compared to 2015), and they are stable with respect to our 2015 measurements (with small fluctuations, at the level of a fraction of a standard deviation, which is consistent with changes in data processing). Polarizationonly bispectra display a significant improvement in robustness; they can now be used independently to set primordial NG constraints with a sensitivity comparable to WMAP temperaturebased results and they give excellent agreement. In addition to the analysis of the standard local, equilateral, and orthogonal bispectrum shapes, we consider a large number of additional cases, such as scaledependent feature and resonance bispectra, isocurvature primordial NG, and paritybreaking models, where we also place tight constraints but do not detect any signal. The nonprimordial lensing bispectrum is, however, detected with an improved significance compared to 2015, excluding the null hypothesis at 3.5. Beyond estimates of individual shape amplitudes, we also present modelindependent reconstructions and analyses of the Planck CMB bispectrum. Our final constraint on the local primordial trispectrum shape is g(NL)(local) = (5.8 +/ 6.5) x 10(4) g NL local = (  5.8 +/ 6.5 ) x 10 4 (68% CL, statistical), while constraints for other trispectrum shapes are also determined. Exploiting the tight limits on various bispectrum and trispectrum shapes, we constrain the parameter space of different earlyUniverse scenarios that generate primordial NG, including general singlefield models of inflation, multifield models (e.g. curvaton models), models of inflation with axion fields producing parityviolation bispectra in the tensor sector, and inflationary models involving vectorlike fields with directionallydependent bispectra. Our results provide a highprecision test for structureformation scenarios, showing complete agreement with the basic picture of the Lambda CDM cosmology regarding the statistics of the initial conditions, with cosmic structures arising from adiabatic, passive, Gaussian, and primordial seed perturbations.

