73 research outputs found
Les reines d'Espagne, suivies des reines de Portugal
Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 201
Planck 2013 results. XXII. Constraints on inflation
We analyse the implications of the Planck data for cosmic inflation. The Planck nominal mission temperature anisotropy measurements, combined with the WMAP large-angle polarization, constrain the scalar spectral index to be ns = 0:9603 _ 0:0073, ruling out exact scale invariance at over 5_: Planck establishes an upper bound on the tensor-to-scalar ratio of r < 0:11 (95% CL). The Planck data thus shrink the space of allowed standard inflationary models, preferring potentials with V00 < 0. Exponential potential models, the simplest hybrid inflationary models, and monomial potential models of degree n _ 2 do not provide a good fit to the data. Planck does not find statistically significant running of the scalar spectral index, obtaining dns=dln k = 0:0134 _ 0:0090. We verify these conclusions through a numerical analysis, which makes no slowroll approximation, and carry out a Bayesian parameter estimation and model-selection analysis for a number of inflationary models including monomial, natural, and hilltop potentials. For each model, we present the Planck constraints on the parameters of the potential and explore several possibilities for the post-inflationary entropy generation epoch, thus obtaining nontrivial data-driven constraints. We also present a direct reconstruction of the observable range of the inflaton potential. Unless a quartic term is allowed in the potential, we find results consistent with second-order slow-roll predictions. We also investigate whether the primordial power spectrum contains any features. We find that models with a parameterized oscillatory feature improve the fit by __2 e_ _ 10; however, Bayesian evidence does not prefer these models. We constrain several single-field inflation models with generalized Lagrangians by combining power spectrum data with Planck bounds on fNL. Planck constrains with unprecedented accuracy the amplitude and possible correlation (with the adiabatic mode) of non-decaying isocurvature fluctuations. The fractional primordial contributions of cold dark matter (CDM) isocurvature modes of the types expected in the curvaton and axion scenarios have upper bounds of 0.25% and 3.9% (95% CL), respectively. In models with arbitrarily correlated CDM or neutrino isocurvature modes, an anticorrelated isocurvature component can improve the _2 e_ by approximately 4 as a result of slightly lowering the theoretical prediction for the ` <_ 40 multipoles relative to the higher multipoles. Nonetheless, the data are consistent with adiabatic initial conditions
Planck 2013 results. IX. HFI spectral response
The Planck High Frequency Instrument (HFI) spectral response was determined
through a series of ground based tests conducted with the HFI focal plane in a
cryogenic environment prior to launch. The main goal of the spectral
transmission tests was to measure the relative spectral response (including
out-of-band signal rejection) of all HFI detectors. This was determined by
measuring the output of a continuously scanned Fourier transform spectrometer
coupled with all HFI detectors. As there is no on-board spectrometer within
HFI, the ground-based spectral response experiments provide the definitive data
set for the relative spectral calibration of the HFI. The spectral response of
the HFI is used in Planck data analysis and component separation, this includes
extraction of CO emission observed within Planck bands, dust emission,
Sunyaev-Zeldovich sources, and intensity to polarization leakage. The HFI
spectral response data have also been used to provide unit conversion and
colour correction analysis tools. Verifications of the HFI spectral response
data are provided through comparisons with photometric HFI flight data. This
validation includes use of HFI zodiacal emission observations to demonstrate
out-of-band spectral signal rejection better than 10^8. The accuracy of the HFI
relative spectral response data is verified through comparison with
complementary flight-data based unit conversion coefficients and colour
correction coefficients. These coefficients include those based upon HFI
observations of CO, dust, and Sunyaev-Zeldovich emission. General agreement is
observed between the ground-based spectral characterization of HFI and
corresponding in-flight observations, within the quoted uncertainty of each;
explanations are provided for any discrepancies.Comment: 27 pages, 28 figures, one of the papers associated with the 2013
Planck data releas
Saint or Sinner?: A Reconsideration of the Career of Prince Alexandre de Merode, Chair of the International Olympic Committee’s Medical Commission, 1967-2002
This article explores the role of Prince Alexandre de Merode in heading the IOC’s fight against drugs from the 1960s to 2002. History has not served de Merode very well. He has been presented in simplistic ways that emerge from context rather than evidence – as either a saint or a sinner. IOC-sanctioned accounts cast him in the mould of the saint: a moral and intelligent man who saved sports from doping. In contrast, sports academics have tended to portray him as a sinner: an ineffectual leader who did not develop either the testing systems or the punishments required to prevent doping and who deliberately concealed evidence of high-profile doping cases. This article assesses both representations before presenting information to support a richer and more complicated interpretation
Planck 2015 results. V. LFI calibration
We present a description of the pipeline used to calibrate the Planck Low Frequency Instrument (LFI) timelines into thermodynamic temperatures for the Planck 2015 data release, covering four years of uninterrupted operations. As in the 2013 data release, our calibrator is provided by the spin-synchronous modulation of the cosmic microwave background dipole, but we now use the orbital component, rather than adopting the Wilkinson Microwave Anisotropy Probe (WMAP) solar dipole. This allows our 2015 LFI analysis to provide an independent Solar dipole estimate, which is in excellent agreement with that of HFI and within 1σ (0.3% in amplitude) of the WMAP value. This 0.3% shift in the peak-to-peak dipole temperature from WMAP and a general overhaul of the iterative calibration code increases the overall level of the LFI maps by 0.45% (30 GHz), 0.64% (44 GHz), and 0.82% (70 GHz) in temperature with respect to the 2013 Planck data release, thus reducing the discrepancy with the power spectrum measured by WMAP. We estimate that the LFI calibration uncertainty is now at the level of 0.20% for the 70 GHz map, 0.26% for the 44 GHz map, and 0.35% for the 30 GHz map. We provide a detailed description of the impact of all the changes implemented in the calibration since the previous data release
Planck 2015 results. VI. LFI mapmaking
This paper describes the mapmaking procedure applied to Planck Low Frequency Instrument (LFI) data. The mapmaking step takes as input the calibrated timelines and pointing information. The main products are sky maps of I, Q, and U Stokes components. For the first time, we present polarization maps at LFI frequencies. The mapmaking algorithm is based on a destriping technique, which is enhanced with a noise prior. The Galactic region is masked to reduce errors arising from bandpass mismatch and high signal gradients. We apply horn-uniform radiometer weights to reduce the effects of beam-shape mismatch. The algorithm is the same as used for the 2013 release, apart from small changes in parameter settings. We validate the procedure through simulations. Special emphasis is put on the control of systematics, which is particularly important for accurate polarization analysis. We also produce low-resolution versions of the maps and corresponding noise covariance matrices. These serve as input in later analysis steps and parameter estimation. The noise covariance matrices are validated through noise Monte Carlo simulations. The residual noise in the map products is characterized through analysis of half-ring maps, noise covariance matrices, and simulations
Planck 2015 results. IV. Low Frequency Instrument beams and window functions
This paper presents the characterization of the in-flight beams, the beam window functions, and the associated uncertainties for the Planck Low Frequency Instrument (LFI). The structure of the paper is similar to that presented in the 2013 Planck release; the main differences concern the beam normalization and the delivery of the window functions to be used for polarization analysis. The in-flight assessment of the LFI main beams relies on measurements performed during observations of Jupiter. By stacking data from seven Jupiter transits, the main beam profiles are measured down to –25 dB at 30 and 44 GHz, and down to –30 dB at 70 GHz. It has been confirmed that the agreement between the simulated beams and the measured beams is better than 1% at each LFI frequency band (within the 20 dB contour from the peak, the rms values are 0.1% at 30 and 70 GHz; 0.2% at 44 GHz). Simulated polarized beams are used for the computation of the effective beam window functions. The error budget for the window functions is estimated from both main beam and sidelobe contributions, and accounts for the radiometer band shapes. The total uncertainties in the effective beam window functions are 0.7% and 1% at 30 and 44 GHz, respectively (at ℓ ≈ 600); and 0.5% at 70 GHz (at ℓ ≈ 1000)
Planck 2013 results. III. LFI systematic uncertainties
We present the current estimate of instrumental and systematic effect
uncertainties for the Planck-Low Frequency Instrument relevant to the first
release of the Planck cosmological results. We give an overview of the main
effects and of the tools and methods applied to assess residuals in maps and
power spectra. We also present an overall budget of known systematic effect
uncertainties, which are dominated sidelobe straylight pick-up and imperfect
calibration. However, even these two effects are at least two orders of
magnitude weaker than the cosmic microwave background (CMB) fluctuations as
measured in terms of the angular temperature power spectrum. A residual signal
above the noise level is present in the multipole range , most notably
at 30 GHz, and is likely caused by residual Galactic straylight contamination.
Current analysis aims to further reduce the level of spurious signals in the
data and to improve the systematic effects modelling, in particular with
respect to straylight and calibration uncertainties.Comment: Accepted for publication by A&
Planck 2015 results. XVI. Isotropy and statistics of the CMB
We test the statistical isotropy and Gaussianity of the cosmic microwave background (CMB) anisotropies using observations made by the Planck satellite. Our results are based mainly on the full Planck mission for temperature, but also include some polarization measurements. In particular, we consider the CMB anisotropy maps derived from the multi-frequency Planck data by several component-separation methods. For the temperature anisotropies, we find excellent agreement between results based on these sky maps over both a very large fraction of the sky and a broad range of angular scales, establishing that potential foreground residuals do not affect our studies. Tests of skewness, kurtosis, multi-normality, N-point functions, and Minkowski functionals indicate consistency with Gaussianity, while a power deficit at large angular scales is manifested in several ways, for example low map variance. The results of a peak statistics analysis are consistent with the expectations of a Gaussian random field. The “Cold Spot” is detected with several methods, including map kurtosis, peak statistics, and mean temperature profile. We thoroughly probe the large-scale dipolar power asymmetry, detecting it with several independent tests, and address the subject of a posteriori correction. Tests of directionality suggest the presence of angular clustering from large to small scales, but at a significance that is dependent on the details of the approach. We perform the first examination of polarization data, finding the morphology of stacked peaks to be consistent with the expectations of statistically isotropic simulations. Where they overlap, these results are consistent with the Planck 2013 analysis based on the nominal mission data and provide our most thorough view of the statistics of the CMB fluctuations to date
Planck 2015 results: XXV. Diffuse low-frequency Galactic foregrounds
We discuss the Galactic foreground emission between 20 and 100 GHz based on observations by Planck and WMAP. The total intensity in this part of the spectrum is dominated by free-free and spinning dust emission, whereas the polarized intensity is dominated by synchrotron emission. The Commander component-separation tool has been used to separate the various astrophysical processes in total intensity. Comparison with radio recombination line templates verifies the recovery of the free-free emission along the Galactic plane. Comparison of the high-latitude H\u3b1 emission with our free-free map shows residuals that correlate with dust optical depth, consistent with a fraction (\ue2\u2030 30%) of H\u3b1 having been scattered by high-latitude dust. We highlight a number of diffuse spinning dust morphological features at high latitude. There is substantial spatial variation in the spinning dust spectrum, with the emission peak (in I\u3bd) ranging from below 20 GHz to more than 50 GHz. There is a strong tendency for the spinning dust component near many prominent H ii regions to have a higher peak frequency, suggesting that this increase in peak frequency is associated with dust in the photo-dissociation regions around the nebulae. The emissivity of spinning dust in these diffuse regions is of the same order as previous detections in the literature. Over the entire sky, the Commander solution finds more anomalous microwave emission (AME) than the WMAP component maps, at the expense of synchrotron and free-free emission. This can be explained by the difficulty in separating multiple broadband components with a limited number of frequency maps. Future surveys, particularly at 5-20 GHz, will greatly improve the separation by constraining the synchrotron spectrum. We combine Planck and WMAP data to make the highest signal-to-noise ratio maps yet of the intensity of the all-sky polarized synchrotron emission at frequencies above a few GHz. Most of the high-latitude polarized emission is associated with distinct large-scale loops and spurs, and we re-discuss their structure. We argue that nearly all the emission at 40deg > l >-90deg is part of the Loop I structure, and show that the emission extends much further in to the southern Galactic hemisphere than previously recognised, giving Loop I an ovoid rather than circular outline. However, it does not continue as far as the "Fermi bubble/microwave haze", making it less probable that these are part of the same structure. We identify a number of new faint features in the polarized sky, including a dearth of polarized synchrotron emission directly correlated with a narrow, roughly 20deg long filament seen in H\u3b1 at high Galactic latitude. Finally, we look for evidence of polarized AME, however many AME regions are significantly contaminated by polarized synchrotron emission, and we find a 2\u3c3 upper limit of 1.6% in the Perseus region
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