The European Space Agency's Planck satellite, which is 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. In February 2015, ESA and the Planck Collaboration released the second set of cosmology products based on data from the entire Planck mission, including both temperature and polarization, along with a set of scientific and technical papers and a web-based explanatory supplement. This paper gives an overview of the main characteristics of the data and the data products in the release, as well as the associated cosmological and astrophysical science results and papers. The data products include maps of the cosmic microwave background (CMB), the thermal Sunyaev-Zeldovich effect, diffuse foregrounds in temperature and polarization, catalogues of compact Galactic and extragalactic sources (including separate catalogues of Corresponding author: C. R. Lawrence, e-mail: charles.lawrence@jpl.nasa.govArticle published by EDP Sciences A1, page 1 of 38 A&A 594, A1 (2016) Sunyaev-Zeldovich clusters and Galactic cold clumps), and extensive simulations of signals and noise used in assessing uncertainties and the performance of the analysis methods. The likelihood code used to assess cosmological models against the Planck data is described, along with a CMB lensing likelihood. Scientific results include cosmological parameters derived from CMB power spectra, gravitational lensing, and cluster counts, as well as constraints on inflation, non-Gaussianity, primordial magnetic fields, dark energy, and modified gravity, and new results on low-frequency Galactic foregrounds.

The 9C survey of radio sources with the Ryle Telescope at 15.2 GHz was set up to survey the fields observed with the cosmic microwave background telescope, the Very Small Array. In our first paper, we described three regions of the survey, constituting a total area of 520 deg2 to a completeness limit of ≈25 mJy. Here we report on a series of deeper regions, amounting to an area of 115 deg2 complete to ≈10 mJy and of 29 deg2 complete to ≈5.5 mJy. We have investigated the source counts and the distributions of the 1.4 to 15.2 GHz spectral indices (α15.21.4) for these deeper samples. The whole catalogue of 643 sources is available online. Down to our lower limit of 5.5 mJy, we detect no evidence for any change in the differential source count from the earlier fitted count above 25 mJy, n(S) = 51(S/Jy)−2.15 Jy−1 sr−1. We have matched both our new and earlier catalogues with the NRAO VLA Sky Survey (NVSS) catalogue at 1.4 GHz and selected flux‐limited samples at both 15 and 1.4 GHz. As expected, we find that the proportions of sources with flat and rising spectra in the samples selected at 15 GHz are significantly higher than those in the samples selected at 1.4 GHz. In addition, for 15‐GHz samples selected in three flux density ranges, we detect a significant shift in the median value of α15.21.4: the higher the flux densities the higher the proportions of sources with flat and rising spectra. In our area complete to ≈10 mJy, we find five sources between 10 and 15 mJy at 15 GHz, amounting to 4.3 per cent of sources in this range, with no counterpart in the NVSS catalogue. This implies that, had we relied on NVSS for locating our sources, we could have missed a significant proportion of them at low flux densities. Our results illustrate the problems inherent in using a low‐frequency catalogue to characterize the source population at a much higher frequency and emphasize the value of our blind 15.2‐GHz survey.

We present observations and analysis of a sample of 123 galaxy clusters from the 2013 Planck catalogue of Sunyaev-Zel'dovich sources with the Arcminute Microkelvin Imager (AMI), a ground-based radio interferometer. AMI provides an independent measurement with higher angular resolution, 3 arcmin compared to the Planck beams of 5-10 arcmin. The AMI observations thus provide validation of the cluster detections, improved positional estimates, and a consistency check on the fitted size (θ s ) and flux (Y tot ) parameters in the generalised Navarro, Frenk and White (GNFW) model. We detect 99 of the clusters. We use the AMI positional estimates to check the positional estimates and error-bars produced by the Planck algorithms PowellSnakes and MMF3. We find that Y tot values as measured by AMI are biased downwards with respect to the Planck constraints, especially for high Planck-S/N clusters. We perform simulations to show that this can be explained by deviation from the universal pressure profile shape used to model the clusters. We show that AMI data can constrain the α and β parameters describing the shape of the profile in the GNFW model for individual clusters provided careful attention is paid to the degeneracies between parameters, but one requires information on a wider range of angular scales than are present in AMI data alone to correctly constrain all parameters simultaneously.

No abstract