228 research outputs found
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Planck 2015 results: XXVI. The Second Planck Catalogue of Compact Sources
The Second Planck Catalogue of Compact Sources is a list of discrete objects detected in single-frequency maps from the full duration of the Planck mission and supersedes previous versions. It consists of compact sources, both Galactic and extragalactic, detected over the entire sky. Compact sources detected in the lower frequency channels are assigned to the PCCS2, while at higher frequencies they are assigned to one of two subcatalogues, the PCCS2 or PCCS2E, depending on their location on the sky. The first of these (PCCS2) covers most of the sky and allows the user to produce subsamples at higher reliabilities than the target 80% integral reliability of the catalogue. The second (PCCS2E) contains sources detected in sky regions where the diffuse emission makes it difficult to quantify the reliability of the detections. Both the PCCS2 and PCCS2E include polarization measurements, in the form of polarized flux densities, or upper limits, and orientation angles for all seven polarization-sensitive Planck channels. The improved data-processing of the full-mission maps and their reduced noise levels allow us to increase the number of objects in the catalogue, improving its completeness for the target 80% reliability as compared with the previous versions, the PCCS and the Early Release Compact Source Catalogue (ERCSC).The Planck Collaboration acknowledges the support of: ESA; CNES and CNRS/INSU-IN2P3-INP (France); ASI, CNR, and INAF (Italy); NASA and DoE (USA); STFC and UKSA (UK); CSIC, MINECO, JA, and, RES (Spain); Tekes, AoF, and CSC (Finland); DLR and MPG (Germany); CSA (Canada); DTU Space (Denmark); SER/SSO (Switzerland); RCN (Norway); SFI (Ireland); FCT/MCTES (Portugal); ERC and PRACE (EU). A description of the Planck Collaboration and a list of its members, indicating which technical or scientific activities they have been involved in, can be found at http://www.cosmos.esa.int/web/planck/planck-collaboration. We are grateful to the H-ATLAS Executive Committee and primarily to the PIs, S. Eales and L. Dunne, for permission to use the unpublished H-ATLAS catalogue for the validation of the present catalogue. This research has made use of the “Aladin sky atlas” (Bonnarel et al. 2000), developed at CDS, Strasbourg Observatory, France. Part of this work was performed using the Darwin Supercomputer of the University of Cambridge High Performance Computing Service (http://www.hpc.cam.ac.uk/), provided by Dell Inc. using Strategic Research Infrastructure Funding from the HEFCE and funding from the STFC. This research has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration
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Planck 2015 results: XVII. Constraints on primordial non-Gaussianity
The Planck full mission cosmic microwave background (CMB) temperature and E-mode polarization maps are analysed to obtain constraints on primordial non-Gaussianity (NG). Using three classes of optimal bispectrum estimators-separable template-fitting (KSW), binned, and modal-we obtain consistent values for the primordial local, equilateral, and orthogonal bispectrum amplitudes, quoting as our final result from temperature alone localNL = 2.5 ± 5.7, equilNL=-16 ± 70, fNLlocal=2.5±5.7, fNLequil=-16±70, and orthoNL =-34 ± 32fNLortho=-34±33 (68% CL, statistical). Combining temperature and polarization data we obtain fNLlocal=0.8±5.0, fNLequil=-4±43, and fNLortho=-26±21localNL = 0.8 ± 5.0, equilNL=-4 ± 43, and orthoNL =-26 ± 21 (68% CL, statistical). The results are based on comprehensive cross-validation of these estimators on Gaussian and non-Gaussian simulations, are stable across component separation techniques, pass an extensive suite of tests, and are consistent with estimators based on measuring the Minkowski functionals of the CMB. The effect of time-domain de-glitching systematics on the bispectrum is negligible. In spite of these test outcomes we conservatively label the results including polarization data as preliminary, owing to a known mismatch of the noise model in simulations and the data. Beyond estimates of individual shape amplitudes, we present model-independent, three-dimensional reconstructions of the Planck CMB bispectrum and derive constraints on early universe scenarios that generate primordial NG, including general single-field models of inflation, axion inflation, initial state modifications, models producing parity-violating tensor bispectra, and directionally dependent vector models. We present a wide survey of scale-dependent feature and resonance models, accounting for the "look elsewhere" effect in estimating the statistical significance of features. We also look for isocurvature NG, and find no signal, but we obtain constraints that improve significantly with the inclusion of polarization. The primordial trispectrum amplitude in the local model is constrained to be glocalNL = (-0.9 ± 7.7) X 104(68% CL statistical), and we perform an analysis of trispectrum shapes beyond the local case. The global picture that emerges is one of consistency with the premises of the ΛCDM cosmology, namely that the structure we observe today was sourced by adiabatic, passive, Gaussian, and primordial seed perturbations
Planck intermediate results: LVII. Joint Planck LFI and HFI data processing
We present the NPIPE processing pipeline, which produces calibrated frequency maps in temperature and polarization from data from the Planck
Low Frequency Instrument (LFI) and High Frequency Instrument (HFI) using high-performance computers. NPIPE represents a natural evolution
of previous Planck analysis efforts, and combines some of the most powerful features of the separate LFI and HFI analysis pipelines. For example,
following the LFI 2018 processing procedure, NPIPE uses foreground polarization priors during the calibration stage in order to break scanninginduced degeneracies. Similarly, NPIPE employs the HFI 2018 time-domain processing methodology to correct for bandpass mismatch at all
frequencies. In addition, NPIPE introduces several improvements, including, but not limited to: inclusion of the 8% of data collected during
repointing manoeuvres; smoothing of the LFI reference load data streams; in-flight estimation of detector polarization parameters; and construction
of maximally independent detector-set split maps. For component-separation purposes, important improvements include: maps that retain the CMB
Solar dipole, allowing for high-precision relative calibration in higher-level analyses; well-defined single-detector maps, allowing for robust CO
extraction; and HFI temperature maps between 217 and 857 GHz that are binned into 0.09 pixels (Nside = 4096), ensuring that the full angular
information in the data is represented in the maps even at the highest Planck resolutions. The net effect of these improvements is lower levels of
noise and systematics in both frequency and component maps at essentially all angular scales, as well as notably improved internal consistency
between the various frequency channels. Based on the NPIPE maps, we present the first estimate of the Solar dipole determined through component
separation across all nine Planck frequencies. The amplitude is (3366.6 ± 2.7) µK, consistent with, albeit slightly higher than, earlier estimates.
From the large-scale polarization data, we derive an updated estimate of the optical depth of reionization of τ = 0.051 ± 0.006, which appears
robust with respect to data and sky cuts. There are 600 complete signal, noise and systematics simulations of the full-frequency and detector-set
maps. As a Planck first, these simulations include full time-domain processing of the beam-convolved CMB anisotropies. The release of NPIPE
maps and simulations is accompanied with a complete suite of raw and processed time-ordered data and the software, scripts, auxiliary data, and
parameter files needed to improve further on the analysis and to run matching simulations
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Planck 2015 results: XIII. Cosmological parameters
We present results based on full-mission Planck observations of temperature
and polarization anisotropies of the CMB. These data are consistent with the
six-parameter inflationary LCDM cosmology. From the Planck temperature and
lensing 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 scalar
spectral index with n_s = 0.968 +/- 0.006. (We quote 68% errors on measured
parameters and 95% limits on other parameters.) Combined with Planck
temperature and lensing data, Planck LFI polarization measurements lead to a
reionization optical depth of tau = 0.066 +/- 0.016. Combining Planck with
other astrophysical data we find N_ eff = 3.15 +/- 0.23 for the effective
number of relativistic degrees of freedom and the sum of neutrino masses is
constrained 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 consistent
with 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. We
find no evidence for isocurvature perturbations or cosmic defects. The equation
of state of dark energy is constrained to w = -1.006 +/- 0.045. Standard big
bang nucleosynthesis predictions for the Planck LCDM cosmology are in excellent
agreement with observations. We investigate annihilating dark matter and
deviations from standard recombination, finding no evidence for new physics.
The Planck results for base LCDM are in agreement with BAO data and with the
JLA SNe sample. However the amplitude of the fluctuations is found to be higher
than inferred from rich cluster counts and weak gravitational lensing. Apart
from these tensions, the base LCDM cosmology provides an excellent description
of the Planck CMB observations and many other astrophysical data sets
Planck 2018 results. VII. Isotropy and Statistics of the CMB
Analysis of the Planck 2018 data set indicates that the statistical properties of the cosmic microwave background (CMB) temperature anisotropies are in excellent agreement with previous studies using the 2013 and 2015 data releases. In particular, they are consistent with the Gaussian predictions of the CDM cosmological model, yet also confirm the presence of several so-called "anomalies" on large angular scales. The novelty of the current study, however, lies in being a first attempt at a comprehensive analysis of the statistics of the polarization signal over all angular scales, using either maps of the Stokes parameters, and , or the -mode signal derived from these using a new methodology (which we describe in an appendix). Although remarkable progress has been made in reducing the systematic effects that contaminated the 2015 polarization maps on large angular scales, it is still the case that residual systematics (and our ability to simulate them) can limit some tests of non-Gaussianity and isotropy. However, a detailed set of null tests applied to the maps indicates that these issues do not dominate the analysis on intermediate and large angular scales (i.e., ). In this regime, no unambiguous detections of cosmological non-Gaussianity, or of anomalies corresponding to those seen in temperature, are claimed. Notably, the stacking of CMB polarization signals centred on the positions of temperature hot and cold spots exhibits excellent agreement with the CDM cosmological model, and also gives a clear indication of how Planck provides state-of-the-art measurements of CMB temperature and polarization on degree scales
Planck 2018 results. VII. Isotropy and statistics of the CMB
Analysis of the Planck 2018 data set indicates that the statistical properties of the cosmic microwave background (CMB) temperature anisotropies are in excellent agreement with previous studies using the 2013 and 2015 data releases. In particular, they are consistent with the Gaussian predictions of the CDM cosmological model, yet also confirm the presence of several so-called "anomalies" on large angular scales. The novelty of the current study, however, lies in being a first attempt at a comprehensive analysis of the statistics of the polarization signal over all angular scales, using either maps of the Stokes parameters, and , or the -mode signal derived from these using a new methodology (which we describe in an appendix). Although remarkable progress has been made in reducing the systematic effects that contaminated the 2015 polarization maps on large angular scales, it is still the case that residual systematics (and our ability to simulate them) can limit some tests of non-Gaussianity and isotropy. However, a detailed set of null tests applied to the maps indicates that these issues do not dominate the analysis on intermediate and large angular scales (i.e., ). In this regime, no unambiguous detections of cosmological non-Gaussianity, or of anomalies corresponding to those seen in temperature, are claimed. Notably, the stacking of CMB polarization signals centred on the positions of temperature hot and cold spots exhibits excellent agreement with the CDM cosmological model, and also gives a clear indication of how Planck provides state-of-the-art measurements of CMB temperature and polarization on degree scales
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Planck intermediate results: LII. Planet flux densities
Measurements of flux density are described for five planets, Mars, Jupiter,
Saturn, Uranus, and Neptune, across the six Planck High Frequency Instrument
frequency bands (100-857 GHz) and these are then compared with models and
existing data. In our analysis, we have also included estimates of the
brightness of Jupiter and Saturn at the three frequencies of the Planck Low
Frequency Instrument (30, 44, and 70 GHz). The results provide constraints on
the intrinsic brightness and the brightness time-variability of these planets.
The majority of the planet flux density estimates are limited by systematic
errors, but still yield better than 1% measurements in many cases. Applying
data from Planck HFI, the Wilkinson Microwave Anisotropy Probe (WMAP), and the
Atacama Cosmology Telescope (ACT) to a model that incorporates contributions
from Saturn's rings to the planet's total flux density suggests a best fit
value for the spectral index of Saturn's ring system of over the 30-1000 GHz frequency range. The average ratio between
the Planck-HFI measurements and the adopted model predictions for all five
planets (excluding Jupiter observations for 353 GHz) is 0.997, 0.997, 1.018,
and 1.032 for 100, 143, 217, and 353 GHz, respectively. Model predictions for
planet thermodynamic temperatures are therefore consistent with the absolute
calibration of Planck-HFI detectors at about the three-percent-level. We
compare our measurements with published results from recent cosmic microwave
background experiments. In particular, we observe that the flux densities
measured by Planck HFI and WMAP agree to within 2%. These results allow
experiments operating in the mm-wavelength range to cross-calibrate against
Planck and improve models of radiative transport used in planetary science
Planck 2015 results XXVI. The Second Planck Catalogue of Compact Sources
The Second Planck Catalogue of Compact Sources is a list of discrete objects detected in single-frequency maps from the full duration of the Planck mission and supersedes previous versions. It consists of compact sources, both Galactic and extragalactic, detected over the entire sky. Compact sources detected in the lower frequency channels are assigned to the PCCS2, while at higher frequencies they are assigned to one of two subcatalogues, the PCCS2 or PCCS2E, depending on their location on the sky. The first of these (PCCS2) covers most of the sky and allows the user to produce subsamples at higher reliabilities than the target 80% integral reliability of the catalogue. The second ( PCCS2E) contains sources detected in sky regions where the diffuse emission makes it difficult to quantify the reliability of the detections. Both the PCCS2 and PCCS2E include polarization measurements, in the form of polarized flux densities, or upper limits, and orientation angles for all seven polarization-sensitive Planck channels. The improved data-processing of the full-mission maps and their reduced noise levels allow us to increase the number of objects in the catalogue, improving its completeness for the target 80% reliability as compared with the previous versions, the PCCS and the Early Release Compact Source Catalogue (ERCSC)
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