321 results found
Ade PAR, Aghanim N, Arnaud M, et al., 2016, Planck 2015 results XXI. The integrated Sachs-Wolfe effect, ASTRONOMY & ASTROPHYSICS, Vol: 594, ISSN: 1432-0746
Ade PAR, Aghanim N, Arnaud M, et al., 2016, Planck 2015 results XIX. Constraints on primordial magnetic fields, ASTRONOMY & ASTROPHYSICS, Vol: 594, ISSN: 1432-0746
Ade PAR, Aghanim N, Arnaud M, et al., 2016, Planck 2015 results XVII. Constraints on primordial non-Gaussianity, ASTRONOMY & ASTROPHYSICS, Vol: 594, ISSN: 1432-0746
Ade PAR, Aghanim N, Arnaud M, et al., 2016, Planck 2015 results XIV. Dark energy and modified gravity, ASTRONOMY & ASTROPHYSICS, Vol: 594, ISSN: 1432-0746
Adam R, Ade PAR, Aghanim N, et al., 2016, Planck 2015 results X. Diffuse component separation: Foreground maps, ASTRONOMY & ASTROPHYSICS, Vol: 594, ISSN: 1432-0746
Ade PAR, Aghanim N, Akrami Y, et al., 2016, Planck 2015 results XVI. Isotropy and statistics of the CMB, ASTRONOMY & ASTROPHYSICS, Vol: 594, ISSN: 1432-0746
Ade PAR, Aumont J, Baccigalupi C, et al., 2016, Planck 2015 results III. LFI systematic uncertainties, ASTRONOMY & ASTROPHYSICS, Vol: 594, ISSN: 1432-0746
Ade PAR, Aghanim N, Arnaud M, et al., 2016, Planck 2015 results XII. Full focal plane simulations, ASTRONOMY & ASTROPHYSICS, Vol: 594, ISSN: 1432-0746
Ade PAR, Aghanim N, Alves MIR, et al., 2016, Planck 2015 results XXV. Diffuse low-frequency Galactic foregrounds, ASTRONOMY & ASTROPHYSICS, Vol: 594, ISSN: 1432-0746
Ade PAR, Aghanim N, Arnaud M, et al., 2016, Planck 2015 results XXIII. The thermal Sunyaev-Zeldovich effect-cosmic infrared background correlation, ASTRONOMY & ASTROPHYSICS, Vol: 594, ISSN: 1432-0746
Adam R, Ade PAR, Aghanim N, et al., 2016, Planck 2015 results IX. Diffuse component separation: CMB maps, ASTRONOMY & ASTROPHYSICS, Vol: 594, ISSN: 1432-0746
Ade PAR, Aghanim N, Ashdown M, et al., 2016, Planck 2015 results II. Low Frequency Instrument data processings, ASTRONOMY & ASTROPHYSICS, Vol: 594, ISSN: 1432-0746
Ade PAR, Aghanim N, Ashdown M, et al., 2016, Planck 2015 results IV. Low Frequency Instrument beams and window functions, ASTRONOMY & ASTROPHYSICS, Vol: 594, ISSN: 1432-0746
Jaffe A, 2016, Physics: Finding the time, Nature, Vol: 537, ISSN: 0028-0836
Aghanim N, Arnaud M, Ashdown M, et al., 2016, Planck 2015 results. XI. CMB power spectra, likelihoods, and robustness of parameters, Astronomy & Astrophysics, Vol: 594, ISSN: 0004-6361
This paper presents the Planck 2015 likelihoods, statistical descriptions of the 2-point correlationfunctions of the cosmic microwave background (CMB) temperature and polarization fluctuations that account for relevant uncertainties, both instrumental and astrophysical in nature. They are based on the same hybrid approach used for the previous release, i.e., a pixel-based likelihood at low multipoles (ℓ< 30) and a Gaussian approximation to the distribution of cross-power spectra at higher multipoles. The main improvements are the use of more and better processed data and of Planck polarization information, along with more detailed models of foregrounds and instrumental uncertainties. The increased redundancy brought by more than doubling the amount of data analysed enables further consistency checks and enhanced immunity to systematic effects. It also improves the constraining power of Planck, in particular with regard to small-scale foreground properties. Progress in the modelling of foreground emission enables the retention of a larger fraction of the sky to determine the properties of the CMB, which also contributes to the enhanced precision of the spectra. Improvements in data processing and instrumental modelling further reduce uncertainties. Extensive tests establish the robustness and accuracy of the likelihood results, from temperature alone, from polarization alone, and from their combination. For temperature, we also perform a full likelihood analysis of realistic end-to-end simulations of the instrumental response to the sky, which were fed into the actual data processing pipeline; this does not reveal biases from residual low-level instrumental systematics. Even with the increase in precision and robustness, the ΛCDM cosmological model continues to offer a very good fit to the Planck data. The slope of the primordial scalar fluctuations, ns, is confirmed smaller than unity at more than 5σ from Planck alone. We further validate the robustn
Collaboration P, Ade PAR, Aghanim N, et al., 2016, Planck 2015 results. XXVI. The Second Planck Catalogue of Compact Sources, Astronomy & Astrophysics, Vol: 594, ISSN: 1432-0746
The Second Planck Catalogue of Compact Sources is a catalogue of sourcesdetected in single-frequency maps from the full duration of the Planck missionand supersedes previous versions of the Planck compact source catalogues. Itconsists of compact sources, both Galactic and extragalactic, detected over theentire sky. Compact sources detected in the lower frequency channels areassigned to the PCCS2, while at higher frequencies they are assigned to one oftwo sub-catalogues, the PCCS2 or PCCS2E, depending on their location on thesky. The first of these catalogues covers most of the sky and allows the userto produce subsamples at higher reliabilities than the target 80% integralreliability of the catalogue. The PCCS2E contains sources detected in skyregions where the diffuse emission makes it difficult to quantify thereliability of the detections. Both the PCCS2 and PCCS2E include polarizationmeasurements, in the form of polarized flux densities, or upper limits, andorientation angles for all seven polarization-sensitive Planck channels. Theimproved data-processing of the full-mission maps and their reduced noiselevels allow us to increase the number of objects in the catalogue, improvingits completeness for the target 80 % reliability as compared with the previousversions, the PCCS and ERCSC catalogues.
Collaboration P, Adam R, Ade PAR, et al., 2016, Planck 2015 results. I. Overview of products and scientific results
The European Space Agency's Planck satellite, dedicated to studying the earlyUniverse and its subsequent evolution, was launched 14~May 2009 and scanned themicrowave and submillimetre sky continuously between 12~August 2009 and23~October 2013. In February~2015, ESA and the Planck Collaboration releasedthe second set of cosmology products based on data from the entire Planckmission, including both temperature and polarization, along with a set ofscientific and technical papers and a web-based explanatory supplement. Thispaper gives an overview of the main characteristics of the data and the dataproducts in the release, as well as the associated cosmological andastrophysical science results and papers. The science products include maps ofthe cosmic microwave background (CMB), the thermal Sunyaev-Zeldovich effect,and diffuse foregrounds in temperature and polarization, catalogues of compactGalactic and extragalactic sources (including separate catalogues ofSunyaev-Zeldovich clusters and Galactic cold clumps), and extensive simulationsof signals and noise used in assessing the performance of the analysis methodsand assessment of uncertainties. The likelihood code used to assesscosmological models against the Planck data are described, as well as a CMBlensing likelihood. Scientific results include cosmological parameters derivingfrom CMB power spectra, gravitational lensing, and cluster counts, as well asconstraints on inflation, non-Gaussianity, primordial magnetic fields, darkenergy, and modified gravity.
Collaboration P, Ade PAR, Aghanim N, et al., 2016, Planck 2015 results. XXVIII. The Planck Catalogue of Galactic Cold Clumps, Astronomy & Astrophysics, Vol: 594, ISSN: 1432-0746
We present the Planck Catalogue of Galactic Cold Clumps (PGCC), an all-skycatalogue of Galactic cold clump candidates detected by Planck. This catalogueis the full version of the Early Cold Core (ECC) catalogue, which was madeavailable in 2011 with the Early Release Compact Source Catalogue (ERCSC) andcontained 915 high S/N sources. It is based on the Planck 48 months missiondata that are currently being released to the astronomical community. The PGCCcatalogue is an observational catalogue consisting exclusively of Galactic coldsources. The three highest Planck bands (857, 545, 353 GHz) have been combinedwith IRAS data at 3 THz to perform a multi-frequency detection of sourcescolder than their local environment. After rejection of possible extragalacticcontaminants, the PGCC catalogue contains 13188 Galactic sources spread acrossthe whole sky, i.e., from the Galactic plane to high latitudes, following thespatial distribution of the main molecular cloud complexes. The mediantemperature of PGCC sources lies between 13 and 14.5 K, depending on thequality of the flux density measurements, with a temperature ranging from 5.8to 20 K after removing sources with the 1% largest temperature estimates. Usingseven independent methods, reliable distance estimates have been obtained for5574 sources, which allows us to derive their physical properties such as theirmass, physical size, mean density and luminosity. The PGCC sources are locatedmainly in the solar neighbourhood, up to a distance of 10.5 kpc towards theGalactic centre, and range from low-mass cores to large molecular clouds.Because of this diversity and because the PGCC catalogue contains sources invery different environments, the catalogue is useful to investigate theevolution from molecular clouds to cores. Finally, the catalogue also includes54 additional sources located in the SMC and LMC.
Ade PAR, Aghanim N, Arnaud M, et al., 2016, Planck 2015 results XVIII. Background geometry and topology of the Universe, Astronomy & Astrophysics, Vol: 594, Pages: A18-A18, ISSN: 0004-6361
Maps of cosmic microwave background (CMB) temperature and polarization from the 2015 release of Planck data provide the highestquality full-sky view of the surface of last scattering available to date. This enables us to detect possible departures from a globally isotropic cosmology. We present the first searches using CMB polarization for correlations induced by a possible non-trivial topology with a fundamental domain that intersects, or nearly intersects, the last-scattering surface (at comoving distance χrec), both via a direct scan for matched circular patterns at the intersections and by an optimal likelihood calculation for specific topologies. We specialize to flat spaces with cubic toroidal (T3) and slab (T1) topologies, finding that explicit searches for the latter are sensitive to other topologies with antipodal symmetry. These searches yield no detection of a compact topology with a scale below the diameter of the last-scattering surface. The limits on the radius ℛi of the largest sphere inscribed in the fundamental domain (at log-likelihood ratio Δlnℒ > −5 relative to a simply-connected flat Planck best-fit model) are: ℛi > 0.97 χrec for the T3 cubic torus; and ℛi > 0.56 χrec for the T1 slab. The limit for the T3 cubic torus from the matched-circles search is numerically equivalent, ℛi > 0.97 χrec at 99% confidence level from polarization data alone. We also perform a Bayesian search for an anisotropic global Bianchi VIIh geometry. In the non-physical setting, where the Bianchi cosmology is decoupled from the standard cosmology, Planck temperature data favour the inclusion of a Bianchi component with a Bayes factor of at least 2.3 units of log-evidence. However, the cosmological parameters that generate this pattern are in strong disagreement with those found from CMB anisotropy data alone. Fitting the induced polarization pattern for this model to the Planck data requires an amplitude of −0.10 ± 0.04
Collaboration P, Ade PAR, Aghanim N, et al., 2016, Planck 2015 results. XIII. Cosmological parameters, A, Vol: 594
We present results based on full-mission Planck observations of temperatureand polarization anisotropies of the CMB. These data are consistent with thesix-parameter inflationary LCDM cosmology. From the Planck temperature andlensing data, for this cosmology we find a Hubble constant, H0= (67.8 +/- 0.9)km/s/Mpc, a matter density parameter Omega_m = 0.308 +/- 0.012 and a scalarspectral index with n_s = 0.968 +/- 0.006. (We quote 68% errors on measuredparameters and 95% limits on other parameters.) Combined with Plancktemperature and lensing data, Planck LFI polarization measurements lead to areionization optical depth of tau = 0.066 +/- 0.016. Combining Planck withother astrophysical data we find N_ eff = 3.15 +/- 0.23 for the effectivenumber of relativistic degrees of freedom and the sum of neutrino masses isconstrained to < 0.23 eV. Spatial curvature is found to be |Omega_K| < 0.005.For LCDM we find a limit on the tensor-to-scalar ratio of r <0.11 consistentwith the B-mode constraints from an analysis of BICEP2, Keck Array, and Planck(BKP) data. Adding the BKP data leads to a tighter constraint of r < 0.09. Wefind no evidence for isocurvature perturbations or cosmic defects. The equationof state of dark energy is constrained to w = -1.006 +/- 0.045. Standard bigbang nucleosynthesis predictions for the Planck LCDM cosmology are in excellentagreement with observations. We investigate annihilating dark matter anddeviations from standard recombination, finding no evidence for new physics.The Planck results for base LCDM are in agreement with BAO data and with theJLA SNe sample. However the amplitude of the fluctuations is found to be higherthan inferred from rich cluster counts and weak gravitational lensing. Apartfrom these tensions, the base LCDM cosmology provides an excellent descriptionof the Planck CMB observations and many other astrophysical data sets.
Adam R, Ade PAR, Aghanim N, et al., 2016, Planck 2015 results VIII. High Frequency Instrument data processing: Calibration and maps, Astronomy & Astrophysics, Vol: 594, Pages: 1-28, ISSN: 0004-6361
This paper describes the processing applied to the cleaned, time-ordered information obtained from the Planck High Frequency Instrument (HFI) with the aim of producing photometrically calibrated maps in temperature and (for the first time) in polarization. The data from the entire 2.5-year HFI mission include almost five full-sky surveys. HFI observes the sky over a broad range of frequencies, from 100 to 857 GHz. To obtain the best accuracy on the calibration over such a large range, two different photometric calibration schemes have been used. The 545 and 857 GHz data are calibrated using models of planetary atmospheric emission. The lower frequencies (from 100 to 353 GHz) are calibrated using the time-variable cosmological microwave background dipole, which we call the orbital dipole. This source of calibration only depends on the satellite velocity with respect to the solar system. Using a CMB temperature of TCMB = 2.7255 ± 0.0006 K, it permits an independent measurement of the amplitude of the CMB solar dipole (3364.3 ± 1.5 μK), which is approximatively 1σ higher than the WMAP measurement with a direction that is consistent between the two experiments. We describe the pipeline used to produce the maps ofintensity and linear polarization from the HFI timelines, and the scheme used to set the zero level of the maps a posteriori. We also summarize the noise characteristics of the HFI maps in the 2015 Planck data release and present some null tests to assess their quality. Finally, we discuss the major systematic effects and in particular the leakage induced by flux mismatch between the detectors that leads to spurious polarization signal.
Collaboration P, Adam R, Ade PAR, et al., 2016, Planck 2015 results. VII. HFI TOI and beam processing, A, Vol: 594
The Planck High Frequency Instrument (HFI) has observed the full sky at sixfrequencies (100, 143, 217, 353, 545, and 857 GHz) in intensity and at fourfrequencies in linear polarization (100, 143, 217, and 353 GHz). In order toobtain sky maps, the time-ordered information (TOI) containing the detector andpointing samples must be processed and the angular response must be assessed.The full mission TOI is included in the Planck 2015 release. This paperdescribes the HFI TOI and beam processing for the 2015 release. HFI calibrationand map-making are described in a companion paper. The main pipeline has beenmodified since the last release (2013 nominal mission in intensity only), byincluding a correction for the non-linearity of the warm readout and byimproving the model of the bolometer time response. The beam processing is anessential tool that derives the angular response used in all the Planck sciencepapers and we report an improvement in the effective beam window functionuncertainty of more than a factor 10 relative to the 2013 release. Noisecorrelations introduced by pipeline filtering function are assessed usingdedicated simulations. Angular cross-power spectra using datasets that aredecorrelated in time are immune to the main systematic effects.
Collaboration P, Ade PAR, Aghanim N, et al., 2016, Planck 2015 results. XXVII. The Second Planck Catalogue of Sunyaev-Zeldovich Sources, Astronomy & Astrophysics, Vol: 594, ISSN: 0004-6361
We present the all-sky Planck catalogue of Sunyaev-Zeldovich (SZ) sourcesdetected from the 29 month full-mission data. The catalogue (PSZ2) is thelargest SZ-selected sample of galaxy clusters yet produced and the deepestall-sky catalogue of galaxy clusters. It contains 1653 detections, of which1203 are confirmed clusters with identified counterparts in external data-sets,and is the first SZ-selected cluster survey containing > $10^3$ confirmedclusters. We present a detailed analysis of the survey selection function interms of its completeness and statistical reliability, placing a lower limit of83% on the purity. Using simulations, we find that the Y5R500 estimates arerobust to pressure-profile variation and beam systematics, but accurateconversion to Y500 requires. the use of prior information on the clusterextent. We describe the multi-wavelength search for counterparts in ancillarydata, which makes use of radio, microwave, infra-red, optical and X-raydata-sets, and which places emphasis on the robustness of the counterpartmatch. We discuss the physical properties of the new sample and identify apopulation of low-redshift X-ray under- luminous clusters revealed by SZselection. These objects appear in optical and SZ surveys with consistentproperties for their mass, but are almost absent from ROSAT X-ray selectedsamples.
Bao C, Baccigalupi C, Gold B, et al., 2016, MAXIMUM LIKELIHOOD FOREGROUND CLEANING FOR COSMIC MICROWAVE BACKGROUND POLARIMETERS IN THE PRESENCE OF SYSTEMATIC EFFECTS, Astrophysical Journal, Vol: 819, ISSN: 0004-637X
© 2016. The American Astronomical Society. All rights reserved. We extend a general maximum likelihood foreground estimation for cosmic microwave background (CMB) polarization data to include estimation of instrumental systematic effects. We focus on two particular effects: frequency band measurement uncertainty and instrumentally induced frequency dependent polarization rotation. We assess the bias induced on the estimation of the B-mode polarization signal by these two systematic effects in the presence of instrumental noise and uncertainties in the polarization and spectral index of Galactic dust. Degeneracies between uncertainties in the band and polarization angle calibration measurements and in the dust spectral index and polarization increase the uncertainty in the extracted CMB B-mode power, and may give rise to a biased estimate. We provide a quantitative assessment of the potential bias and increased uncertainty in an example experimental configuration. For example, we find that with 10% polarized dust, a tensor to scalar ratio of r = 0.05, and the instrumental configuration of the E and B experiment balloon payload, the estimated CMB B-mode power spectrum is recovered without bias when the frequency band measurement has 5% uncertainty or less, and the polarization angle calibration has an uncertainty of up to 4°.
Errard J, Feeney SM, Peiris HV, et al., 2016, Robust forecasts on fundamental physics from the foreground-obscured, gravitationally-lensed CMB polarization, JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, ISSN: 1475-7516
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