Publications (330)763.84 Total impact
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ABSTRACT: We use Planck data to detect the crosscorrelation between the thermal SunyaevZeldovich (tSZ) effect and the infrared emission from the galaxies that make up the the cosmic infrared background (CIB). We first perform a stacking analysis towards Planckconfirmed galaxy clusters. We detect infrared emission produced by dusty galaxies inside these clusters and demonstrate that the infrared emission is about 50% more extended than the tSZ effect. Modelling the emission with a NavarroFrenkWhite profile, we find that the radial profile concentration parameter is $c_{500} = 1.00^{+0.18}_{0.15}$. This indicates that infrared galaxies in the outskirts of clusters have higher infrared flux than clustercore galaxies. We also study the crosscorrelation between tSZ and CIB anisotropies, following three alternative approaches based on power spectrum analyses: (i) using a catalogue of confirmed clusters detected in Planck data; (ii) using an allsky tSZ map built from Planck frequency maps; and (iii) using crossspectra between Planck frequency maps. With the three different methods, we detect the tSZCIB crosspower spectrum at significance levels of (i) 6 $\sigma$, (ii) 3 $\sigma$, and (iii) 4 $\sigma$. We model the tSZCIB crosscorrelation signature and compare predictions with the measurements. The amplitude of the crosscorrelation relative to the fiducial model is $A_{\rm tSZCIB}= 1.2\pm0.3$. This result is consistent with predictions for the tSZCIB crosscorrelation assuming the bestfit cosmological model from Planck 2015 results along with the tSZ and CIB scaling relations.  [Show abstract] [Hide abstract]
ABSTRACT: We present the 8th Full Focal Plane simulation set (FFP8), deployed in support of the Planck 2015 results. FFP8 consists of 10 fiducial mission realizations reduced to 18144 maps, together with the most massive suite of Monte Carlo realizations of instrument noise and CMB ever generated, comprising $10^4$ mission realizations reduced to about $10^6$ maps. The resulting maps incorporate the dominant instrumental, scanning, and data analysis effects; remaining subdominant effects will be included in future updates. Generated at a cost of some 25 million CPUhours spread across multiple highperformancecomputing (HPC) platforms, FFP8 is used for the validation and verification of analysis algorithms, as well as their implementations, and for removing biases from and quantifying uncertainties in the results of analyses of the real data.  [Show abstract] [Hide abstract]
ABSTRACT: Determining magnetic field properties in different environments of the cosmic largescale structure as well as their evolution over redshift is a fundamental step toward uncovering the origin of cosmic magnetic fields. Radio observations permit the study of extragalactic magnetic fields via measurements of the Faraday depth of extragalactic radio sources. Our aim is to investigate how much different extragalactic environments contribute to the Faraday depth variance of these sources. We develop a Bayesian algorithm to distinguish statistically Faraday depth variance contributions intrinsic to the source from those due to the medium between the source and the observer. In our algorithm the Galactic foreground and the measurement noise are taken into account as the uncertainty correlations of the galactic model. Additionally, our algorithm allows for the investigation of possible redshift evolution of the extragalactic contribution. This work presents the derivation of the algorithm and tests performed on mock observations. With cosmic magnetism being one of the key science projects of the new generation of radio interferometers we have made predictions for the algorithm's performance on data from the next generation of radio interferometers. Applications to real data are left for future work. 
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ABSTRACT: This paper presents the Planck 2015 likelihoods, statistical descriptions of the 2point correlation functions of CMB temperature and polarization. They use the hybrid approach employed previously: pixelbased at low multipoles, $\ell$, and a Gaussian approximation to the distribution of crosspower spectra at higher $\ell$. The main improvements are the use of more and better processed data and of Planck polarization data, and more detailed foreground and instrumental models. More than doubling the data allows further checks and enhanced immunity to systematics. Progress in foreground modelling enables a larger sky fraction, contributing to enhanced precision. Improvements in processing and instrumental models further reduce uncertainties. Extensive tests establish robustness and accuracy, from temperature, from polarization, and from their combination, and show that the {\Lambda}CDM model continues to offer a very good fit. We further validate the likelihood against specific extensions to this baseline, such as the effective number of neutrino species. For this first detailed analysis of Planck polarization, we concentrate at high $\ell$ on E modes. At low $\ell$ we use temperature at all Planck frequencies along with a subset of polarization. These data take advantage of Planck's wide frequency range to improve the separation of CMB and foregrounds. Within the baseline cosmology this requires a reionization optical depth $\tau=0.078\pm0.019$, significantly lower than without highfrequency data for explicit dust monitoring. At high $\ell$ we detect residual errors in E, typically at the {\mu}K$^2$ level; we thus recommend temperature alone as the high$\ell$ baseline. Nevertheless, Planck high$\ell$ polarization spectra are already good enough to allow a separate highaccuracy determination of the {\Lambda}CDM parameters, consistent with those established from temperature alone.  [Show abstract] [Hide abstract]
ABSTRACT: The Second Planck Catalogue of Compact Sources is a catalogue of sources detected in singlefrequency maps from the full duration of the Planck mission and supersedes previous versions of the Planck compact source catalogues. 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 catalogues 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 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 polarizationsensitive Planck channels. The improved dataprocessing of the fullmission 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 ERCSC catalogues.  Astronomy and Astrophysics 06/2015; DOI:10.1051/00046361/201425172 · 4.38 Impact Factor
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ABSTRACT: (abridged) We discuss the Galactic foreground emission between 20 and 100GHz based on observations by Planck/WMAP. The Commander componentseparation tool has been used to separate the various astrophysical processes in total intensity. Comparison with RRL templates verifies the recovery of the freefree emission along the Galactic plane. Comparison of the highlatitude Halpha emission with our freefree map shows residuals that correlate with dust optical depth, consistent with a fraction (~30%) of Halpha having been scattered by highlatitude 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 ranging from below 20GHz to more than 50GHz. There is a strong tendency for the spinning dust component near many prominent HII regions to have a higher peak frequency, suggesting that this increase in peak frequency is associated with dust in the photodissociation 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 than the WMAP component maps, at the expense of synchrotron and freefree emission. This can be explained by the difficulty in separating multiple broadband components with a limited number of frequency maps. Future surveys (520GHz), will greatly improve the separation by constraining the synchrotron spectrum. We combine Planck/WMAP data to make the highest S/N ratio maps yet of the intensity of the allsky polarized synchrotron emission at frequencies above a few GHz. Most of the highlatitude polarized emission is associated with distinct largescale loops and spurs, and we rediscuss their structure...  [Show abstract] [Hide abstract]
ABSTRACT: We know that magnetic fields are pervasive across all scales in the Universe and over all of cosmic time and yet our understanding of many of the properties of magnetic fields is still limited. We do not yet know when, where or how the first magnetic fields in the Universe were formed, nor do we fully understand their role in fundamental processes such as galaxy formation or cosmic ray acceleration or how they influence the evolution of astrophysical objects. The greatest challenge to addressing these issues has been a lack of deep, broad bandwidth polarimetric data over large areas of the sky. The Square Kilometre Array will radically improve this situation via an allsky polarisation survey that delivers both high quality polarisation imaging in combination with observations of 714 million extragalactic rotation measures. Here we summarise how this survey will improve our understanding of a range of astrophysical phenomena on scales from individual Galactic objects to the cosmic web.  [Show abstract] [Hide abstract]
ABSTRACT: 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 4 years of uninterrupted operations. As in the 2013 data release, our calibrator is provided by the spinsynchronous modulation of the CMB dipole, exploiting both the orbital and solar components. Our 2015 LFI analysis provides an independent Solar dipole estimate in excellent agreement with that of HFI and within $1\sigma$ (0.3 % in amplitude) of the WMAP value. This 0.3 % shift in the peaktopeak dipole temperature from WMAP and a global 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 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.  [Show abstract] [Hide abstract]
ABSTRACT: The quest for a $B$mode imprint from primordial gravity waves on the polarization of the cosmic microwave background (CMB) requires the characterization of foreground polarization from Galactic dust. We present a statistical study of the filamentary structure of the $353\,$GHz Planck Stokes maps at high Galactic latitude, relevant to the study of dust emission as a polarized foreground to the CMB. We filter the intensity and polarization maps to isolate filaments in the range of angular scales where the power asymmetry between $E$modes and $B$modes is observed. Using the Smoothed Hessian Major Axis Filament Finder, we identify 259 filaments at high Galactic latitude, with lengths larger or equal to $2$\deg\ (corresponding to $3.5\,$pc in length for a typical distance of $100\,$pc). These filaments show a preferred orientation parallel to the magnetic field projected onto the plane of the sky, derived from their polarization angles. We present mean maps of the filaments in Stokes $I$, $Q$, $U$, $E$, and $B$, computed by stacking individual images rotated to align the orientations of the filaments. Combining the stacked images and the histogram of relative orientations, we estimate the mean polarization fraction of the filaments to be $11\,$%. Furthermore, we show that the correlation between the filaments and the magnetic field orientations may account for the $E$ and $B$ asymmetry and the $C_{\ell}^{TE}/C_{\ell}^{EE}$ ratio, reported in the power spectra analysis of the Planck $353\,$GHz polarization maps. Future models of the dust foreground for CMB polarization studies will need to take into account the observed correlation between the dust polarization and the structure of interstellar matter.  [Show abstract] [Hide abstract]
ABSTRACT: We present the results of approximately three years of observations of Planck SunyaevZeldovich (SZ) sources with telescopes at the Canary Islands observatories, as part of the general optical followup programme undertaken by the Planck collaboration. In total, 78 SZ sources are discussed. Deep imaging observations were obtained for most of those sources; spectroscopic observations in either in longslit or multiobject modes were obtained for many. We found optical counterparts for 73 of the 78 candidates. This sample includes 53 spectroscopic redshifts determinations, 20 of them obtained with a multiobject spectroscopic mode. The sample contains new redshifts for 27 Planck clusters that were not included in the first Planck SZ source catalogue (PSZ1).  [Show abstract] [Hide abstract]
ABSTRACT: By looking at the kinetic SunyaevZeldovich effect (kSZ) in Planck nominal mission data, we present a significant detection of baryons participating in largescale bulk flows around central galaxies (CGs) at redshift $z\approx 0.1$. We estimate the pairwise momentum of the kSZ temperature fluctuations at the positions of the CGC (Central Galaxy Catalogue) samples extracted from Sloan Digital Sky Survey (DR7) data. For the foregroundcleaned maps, we find $1.8$$2.5\sigma$ detections of the kSZ signal, which are consistent with the kSZ evidence found in individual Planck raw frequency maps, although lower than found in the WMAP9yr W band ($3.3\sigma$). We further reconstruct the peculiar velocity field from the CG density field, and compute for the first time the crosscorrelation function between kSZ temperature fluctuations and estimates of CG radial peculiar velocities. This correlation function yields a $3.0$$3.7$$\sigma$ detection of the peculiar motion of extended gas on Mpc scales, in flows correlated up to distances of 80100 $h^{1}$ Mpc. Both the pairwise momentum estimates and kSZ temperaturevelocity field correlation find evidence for kSZ signatures out to apertures of 8 arcmin and beyond, corresponding to a physical radius of $> 1$ Mpc, more than twice the mean virial radius of halos. This is consistent with the predictions from hydro simulations that most of the baryons are outside the virialized halos. We fit a simple model, in which the temperaturevelocity crosscorrelation is proportional to the signal seen in a semianalytic model built upon Nbody simulations, and interpret the proportionality constant as an "effective" optical depth to Thomson scattering. We find $\tau_T=(1.4\pm0.5)\times 10^{4}$; the simplest interpretation of this measurement is that much of the gas is in a diffuse phase, which contributes little signal to Xray or thermal SZ observations.  [Show abstract] [Hide abstract]
ABSTRACT: Matrix determinants play an important role in data analysis, in particular when Gaussian processes are involved. Due to currently exploding data volumes linear operations  matrices  acting on the data are often not accessible directly, but are only represented indirectly in form of a computer routine. Such a routine implements the transformation a data vector undergoes under matrix multiplication. Meanwhile efficient probing routines to estimate a matrix's diagonal or trace, based solely on such computationally affordable matrixvector multiplications, are well known and frequently used in signal inference, a stochastic estimate for its determinant is still lacking. In this work a probing method for the logarithm of a determinant of a linear operator is introduced. This method rests upon a reformulation of the logdeterminant by an integral representation and the transformation of the involved terms into stochastic expressions. This stochastic determinant determination enables largesize applications in Bayesian inference, in particular evidence calculations, model comparison, and posterior determination.Physical Review E 04/2015; 92(1). DOI:10.1103/PhysRevE.92.013302 · 2.29 Impact Factor  [Show abstract] [Hide abstract]
ABSTRACT: We present foregroundreduced CMB maps derived from the full Planck data set in both temperature and polarization. Compared to the corresponding Planck 2013 temperature sky maps, the total data volume is larger by a factor of 3.2 for frequencies between 30 and 70 GHz, and by 1.9 for frequencies between 100 and 857 GHz. In addition, systematic errors in the forms of temperaturetopolarization leakage, analoguetodigital conversion uncertainties, and very long time constant errors have been dramatically reduced, to the extent that the cosmological polarization signal may now be robustly recovered on angular scales $\ell\gtrsim40$. On the very largest scales, instrumental systematic residuals are still nonnegligible compared to the expected cosmological signal, and modes with $\ell < 20$ are accordingly suppressed in the current polarization maps by highpass filtering. As in 2013, four different CMB component separation algorithms are applied to these observations, providing a measure of stability with respect to algorithmic and modelling choices. The resulting polarization maps have rms instrumental noise ranging between 0.21 and 0.27$\,\mu\textrm{K}$ averaged over 55 arcmin pixels, and between 4.5 and 6.1$\,\mu\textrm{K}$ averaged over 3.4 arcmin pixels. The cosmological parameters derived from the analysis of temperature power spectra are in agreement at the $1\sigma$ level with the Planck 2015 likelihood. Unresolved mismatches between the noise properties of the data and simulations prevent a satisfactory description of the higherorder statistical properties of the polarization maps. Thus, the primary applications of these polarization maps are those that do not require massive simulations for accurate estimation of uncertainties, for instance estimation of crossspectra and crosscorrelations, or stacking analyses.  [Show abstract] [Hide abstract]
ABSTRACT: Within ten nearby (d < 450 pc) Gould Belt molecular clouds we evaluate statistically the relative orientation between the magnetic field projected on the plane of sky, inferred from the polarized thermal emission of Galactic dust observed by Planck at 353 GHz, and the gas column density structures, quantified by the gradient of the column density, $N_H$. The relative orientation is evaluated pixel by pixel and analyzed in bins of column density using the novel statistical tool Histogram of Relative Orientations. Within most clouds we find that the relative orientation changes progressively with increasing $N_H$ from preferentially parallel or no preferred orientation to preferentially perpendicular. In simulations of magnetohydrodynamic turbulence in molecular clouds this trend in relative orientation is a signature of Alfv\'enic or subAlfv\'enic turbulence, implying that the magnetic field is significant for the gas dynamics at the scales probed by Planck. We compare the deduced magnetic field strength with estimates we obtain from other methods and discuss the implications of the Planck observations for the general picture of molecular cloud formation and evolution.  [Show abstract] [Hide abstract]
ABSTRACT: We present the implications for cosmic inflation of the Planck measurements of the cosmic microwave background (CMB) anisotropies in both temperature and polarization based on the full Planck survey. The Planck full mission temperature data and a first release of polarization data on large angular scales measure the spectral index of curvature perturbations to be $n_\mathrm{s} = 0.968 \pm 0.006$ and tightly constrain its scale dependence to $d n_s/d \ln k =0.003 \pm 0.007$ when combined with the Planck lensing likelihood. When the high$\ell$ polarization data is included, the results are consistent and uncertainties are reduced. The upper bound on the tensortoscalar ratio is $r_{0.002} < 0.11$ (95% CL), consistent with the Bmode polarization constraint $r< 0.12$ (95% CL) obtained from a joint BICEP2/Keck Array and Planck analysis. These results imply that $V(\phi) \propto \phi^2$ and natural inflation are now disfavoured compared to models predicting a smaller tensortoscalar ratio, such as $R^2$ inflation. Three independent methods reconstructing the primordial power spectrum are investigated. The Planck data are consistent with adiabatic primordial perturbations. We investigate inflationary models producing an anisotropic modulation of the primordial curvature power spectrum as well as generalized models of inflation not governed by a scalar field with a canonical kinetic term. The 2015 results are consistent with the 2013 analysis based on the nominal mission data.  [Show abstract] [Hide abstract]
ABSTRACT: We present the allsky Planck catalogue of SunyaevZeldovich (SZ) sources detected from the 29 month fullmission data. The catalogue (PSZ2) is the largest SZselected sample of galaxy clusters yet produced and the deepest allsky catalogue of galaxy clusters. It contains 1653 detections, of which 1203 are confirmed clusters with identified counterparts in external datasets, and is the first SZselected cluster survey containing > 103 confirmed clusters. We present a detailed analysis of the survey selection function in terms of its completeness and statistical reliability, placing a lower limit of 83% on the purity. Using simulations, we find that the Y5R500 estimates are robust to pressureprofile variation and beam systematics, but accurate conversion to Y500 requires. the use of prior information on the cluster extent. We describe the multiwavelength search for counterparts in ancillary data, which makes use of radio, microwave, infrared, optical and Xray datasets, and which places emphasis on the robustness of the counterpart match. We discuss the physical properties of the new sample and identify a population of lowredshift Xray under luminous clusters revealed by SZ selection. These objects appear in optical and SZ surveys with consistent properties for their mass, but are almost absent from ROSAT Xray selected samples.  [Show abstract] [Hide abstract]
ABSTRACT: We present results based on fullmission Planck observations of temperature and polarization anisotropies of the CMB. These data are consistent with the sixparameter 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 tensortoscalar ratio of r <0.11 consistent with the Bmode 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.  [Show abstract] [Hide abstract]
ABSTRACT: We predict and investigate four types of imprint of a stochastic background of primordial magnetic fields (PMFs) on the cosmic microwave background (CMB) anisotropies: the impact of PMFs on the CMB spectra; the effect on CMB polarization induced by Faraday rotation; magneticallyinduced nonGaussianities; and the magneticallyinduced breaking of statistical isotropy. Overall, Planck data constrain the amplitude of PMFs to less than a few nanogauss. In particular, individual limits coming from the analysis of the CMB angular power spectra, using the Planck likelihood, are $B_{1\,\mathrm{Mpc}}< 4.4$ nG (where $B_{1\,\mathrm{Mpc}}$ is the comoving field amplitude at a scale of 1 Mpc) at 95% confidence level, assuming zero helicity, and $B_{1\,\mathrm{Mpc}}< 5.6$ nG when we consider a maximally helical field. For nearly scaleinvariant PMFs we obtain $B_{1\,\mathrm{Mpc}}<2.1$ nG and $B_{1\,\mathrm{Mpc}}<0.7$ nG if the impact of PMFs on the ionization history of the Universe is included in the analysis. From the analysis of magneticallyinduced nonGaussianity we obtain three different values, corresponding to three applied methods, all below 5 nG. The constraint from the magneticallyinduced passivetensor bispectrum is $B_{1\,\mathrm{Mpc}}< 2.8$ nG. A search for preferred directions in the magneticallyinduced passive bispectrum yields $B_{1\,\mathrm{Mpc}}< 4.5$ nG, whereas the the compensatedscalar bispectrum gives $B_{1\,\mathrm{Mpc}}< 3$ nG. The analysis of the Faraday rotation of CMB polarization by PMFs uses the Planck power spectra in $EE$ and $BB$ at 70 GHz and gives $B_{1\,\mathrm{Mpc}}< 1380$ nG. In our final analysis, we consider the harmonicspace correlations produced by Alfv\'en waves, finding no significant evidence for the presence of these waves. Together, these results comprise a comprehensive set of constraints on possible PMFs with Planck data.
Publication Stats
6k  Citations  
763.84  Total Impact Points  
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Institutions

2014

LudwigMaximiliansUniversity of Munich
 Faculty of Physics
München, Bavaria, Germany 
Technische Universität München
München, Bavaria, Germany


2002–2014

Max Planck Institute for Astrophysics
Arching, Bavaria, Germany 
Space Research Institute
Moskva, Moscow, Russia


2002–2011

Midwestern Psychological Association
United States


2006

University of Toronto
Toronto, Ontario, Canada 
Max Planck Institute for Physics
München, Bavaria, Germany


2004

HarvardSmithsonian Center for Astrophysics
 Smithsonian Astrophysical Observatory
Cambridge, Massachusetts, United States


1996–1997

Max Planck Institute for Radio Astronomy
Bonn, North RhineWestphalia, Germany
