Planck 2018 results: IV. Diffuse component separation

We present full-sky maps of the cosmic microwave background (CMB) and polarized synchrotron and thermal dust emission, derived from the third set of Planck frequency maps. These products have significantly lower contamination from instrumental systematic effects than previous versions. The methodologies used to derive these maps follow closely those described in earlier papers, adopting four methods (Commander, NILC, SEVEM, and SMICA) to extract the CMB component, as well as three methods (Commander, GNILC, and SMICA) to extract astrophysical components. Our revised CMB temperature maps agree with corresponding products in the Planck 2015 delivery, whereas the polarization maps exhibit significantly lower large-scale power, reflecting the improved data processing described in companion papers; however, the noise properties of the resulting data products are complicated, and the best available end-to-end simulations exhibit relative biases with respect to the data at the few percent level. Using these maps, we are for the first time able to fit the spectral index of thermal dust independently over 3° regions. We derive a conservative estimate of the mean spectral index of polarized thermal dust emission of ?d?=?1.55? ± ?0.05, where the uncertainty marginalizes both over all known systematic uncertainties and different estimation techniques. For polarized synchrotron emission, we find a mean spectral index of ?s?=??3.1? ± ?0.1, consistent with previously reported measurements. We note that the current data processing does not allow for construction of unbiased single-bolometer maps, and this limits our ability to extract CO emission and correlated components. The foreground results for intensity derived in this paper therefore do not supersede corresponding Planck 2015 products. For polarization the new results supersede the corresponding 2015 products in all respects.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. This work has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement numbers 687312, 776282 and 772253

QUIJOTE scientific results - IV. A northern sky survey in intensity and polarization at 10-20-GHz with the multifrequency instrument

We present QUIJOTE intensity and polarization maps in four frequency bands centred around 11, 13, 17, and 19-GHz, and covering approximately 29?000?deg2, including most of the northern sky region. These maps result from 9000?h of observations taken between May 2013 and June 2018 with the first QUIJOTE multifrequency instrument (MFI), and have angular resolutions of around 1°, and sensitivities in polarization within the range 35?40?µK per 1° beam, being a factor ?2?4 worse in intensity. We discuss the data processing pipeline employed, and the basic characteristics of the maps in terms of real space statistics and angular power spectra. A number of validation tests have been applied to characterize the accuracy of the calibration and the residual level of systematic effects, finding a conservative overall calibration uncertainty of 5 per?cent. We also discuss flux densities for four bright celestial sources (Tau A, Cas A, Cyg A, and 3C274), which are often used as calibrators at microwave frequencies. The polarization signal in our maps is dominated by synchrotron emission. The distribution of spectral index values between the 11?GHz and WMAP 23?GHz map peaks at [Beta] = -3.09 with a standard deviation of 0.14. The measured BB/EE ratio at scales of [L lower case+ = 80 is 0.26 ± 0.07 for a Galactic cut |b| > 10°. We find a positive TE correlation for 11?GHz at large angular scales ([L lower case+ [less than or equivalent to] 50), while the EB and TB signals are consistent with zero in the multipole range 30 [less than or equivalent to] [L lower case+ [less than or equivalent to] 150. The maps discussed in this paper are publicly available.We thank the staff of the Teide Observatory for invaluable assistance in the commissioning and operation of QUIJOTE. The QUIJOTE experiment is being developed by the Instituto de Astrofisica de Canarias (IAC), the Instituto de Fisica de Cantabria (IFCA), and the Universities of Cantabria, Manchester and Cambridge. Partial finan- cial support was provided by the Spanish Ministry of Science and Innovation under the projects AYA2007-68058-C03-01, AYA2007- 68058-C03-02, AYA2010-21766-C03-01, AYA2010-21766-C03-02, AYA2014-60438-P, ESP2015-70646-C2-1-R, AYA2017-84185-P, ESP2017-83921-C2-1-R, AYA2017-90675-REDC (co-funded with EU FEDER funds), PGC2018-101814-B-I00, PID2019-110610RB- C21, PID2020-120514GB-I00, IACA13-3E-2336, IACA15-BE- 3707, EQC2018-004918-P, the Severo Ochoa Programs SEV-2015- 0548 and CEX2019-000920-S, the Maria de Maeztu Program MDM- 2017-0765, and by the Consolider-Ingenio project CSD2010-00064 (EPI: Exploring the Physics of Inflation). We acknowledge support from the ACIISI, Consejeria de Economia, Conocimiento y Empleo del Gobierno de Canarias and the European Regional Development Fund (ERDF) under grant with reference ProID2020010108. This project has received funding from the European Union’s Horizon 2020 - Research and Innovation Framework Programme under grant agreement number 687312 (RADIOFOREGROUNDS). This research made use of computing time available on the high-performance computing systems at the IAC. We thankfully acknowledge the technical expertise and assistance provided by the Spanish Supercomputing Network (Red Espa ˜ nola de Supercom- putaci ´on), as well as the computer resources used: the Deimos/Di v a Supercomputer, located at the IAC. This research used resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The PWV data used in the tests presented in Section 4 comes from the Iza ˜ na Atmospheric Observatory (IZO), and have been made available to us by the Iza ˜ na Atmospheric Research Center (AEMET). SEH and CD acknowledge support from the STFC Consolidated Grant (ST/P000649/1). FP acknowledges support from the Spanish State Research Agency (AEI) under grant number PID2019-105552RB- C43. DT acknowledges the support from the Chinese Academy of Sciences (CAS) President’s International Fellowship Initiative (PIFI) with Grant N. 2020PM0042. Some of the presented results are based on observations obtained with Planck ( http:// www.esa.int/ Planck), an ESA science mission with instruments and contributions directly funded by ESA Member States, NASA, and Canada. We acknowl- edge the use of the Le gac y Archiv e for Microwav e Background Data Analysis (LAMBDA). Support for LAMBDA is provided by the NASA Office of Space Science. Some of the results in this paper have been derived using the HEALPIX (G ´orski et al. 2005 ) and HEALPY (Zonca et al. 2019 ) packages. We also use Numpy (Harris et al. 2020 ), Matplotlib (Hunter 2007 ), and the SKLEARN module (Pedregosa et al. 2011 )

QUIJOTE scientific results-I. Measurements of the intensity and polarisation of the anomalous microwave emission in the Perseus molecular complex

et al.In this paper, we present Q-U-I JOint Tenerife Experiment (QUIJOTE) 10–20 GHz observations (194 h in total over ≈250 deg2) in intensity and polarisation of G159.6-18.5, one of the most widely studied regions harbouring anomalous microwave emission (AME). By combining with other publicly available intensity data, we achieve the most precise spectrum of the AME measured to date in an individual region, with 13 independent data points between 10 and 50 GHz being dominated by this emission. The four QUIJOTE data points provide the first independent confirmation of the downturn of the AME spectrum at low frequencies, initially unveiled by the COSMOlogical Structures On Medium Angular Scales experiment in this region. Our polarisation maps, which have an angular resolution of ≈1° and a sensitivity of ≈ 25 μK beam−1, are consistent with zero polarisation. We obtain upper limits on the polarisation fraction of Π < 6.3 and <2.8 per cent (95 per cent C.L.), respectively, at 12 and 18 GHz (ΠAME < 10.1 and <3.4 per cent with respect to the residual AME intensity), a frequency range where no AME polarisation observations have been reported to date. The combination of these constraints with those from other experiments confirm that all the magnetic dust models based on single-domain grains, and most of those considering randomly oriented magnetic inclusions, predict higher polarisation levels than is observed towards regions with AME. Also, neither of the two considered models of electric dipole emission seems to be compatible with all the observations together. More stringent constraints of the AME polarisation at 10–40 GHz are necessary to disentangle between different models, to which future QUIJOTE data will contribute.This work has been partially funded by the Spanish Ministry of Economy and Competitiveness (MINECO) under the projects AYA2007-68058-C03-01, AYA2010-21766-C03-02, AYA2012-39475-C02-01 and the Consolider-Ingenio project CSD2010-00064 (EPI: Exploring the Physics of Inflation). CD acknowledges support from an ERC Starting (Consolidator) Grant (no. 307209), SH from an STFC-funded studentship, and CHLC from the DIULS (Research Directorship of the University of La Serena).Peer Reviewe

Planck 2015 results. XVI. Isotropy and statistics of the CMB

Cosmology (including clusters of galaxies).-- et al.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.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).Peer Reviewe

QUIJOTE scientific results - VIII. Diffuse polarized foregrounds from component separation with QUIJOTE-MFI

We derive linearly polarized astrophysical component maps in the Northern Sky from the QUIJOTE-MFI data at 11 and 13?GHz in combination with the Wilkinson Microwave Anisotropy Probe K and Ka bands (23 and 33?GHz) and all Planck polarized channels (30-353-GHz), using the parametric component separation method B-SeCRET. The addition of QUIJOTE-MFI data significantly improves the parameter estimation of the low-frequency foregrounds, especially the estimation of the synchrotron spectral index, [beta]s. We present the first detailed ?s map of the Northern Celestial Hemisphere at a smoothing scale of 2°. We find statistically significant spatial variability across the sky. We obtain an average value of ?3.08 and a dispersion of 0.13, considering only pixels with reliable goodness of fit. The power-law model of the synchrotron emission provides a good fit to the data outside the Galactic plane but fails to track the complexity within this region. Moreover, when we assume a synchrotron model with uniform curvature, cs, we find a value of cs = ?0.0797 ± 0.0012. However, there is insufficient statistical significance to determine which model is favoured, either the power law or the power law with uniform curvature. Furthermore, we estimate the thermal dust spectral parameters in polarization. Our cosmic microwave background, synchrotron, and thermal dust maps are highly correlated with the corresponding products of the PR4 Planck release, although some large-scale differences are observed in the synchrotron emission. Finally, we find that the ?s estimation in the high signal-to-noise synchrotron emission areas is prior-independent, while, outside these regions, the prior governs the [beta]s estimation.We thank the staff of the Teide Observatory for invaluable assistance in the commissioning and operation of QUIJOTE. The QUIJOTE experiment is being developed by the Instituto de Astrofisica de Canarias (IAC), the Instituto de Fisica de Cantabria (IFCA), and the Universities of Cantabria, Manchester, and Cambridge. Partial financial support was provided by the Spanish Ministry of Science and Innovation under the projects AYA2007-68058-C03-01, AYA2007- 68058-C03-02, AYA2010-21766-C03-01, AYA2010-21766-C03-02, AYA2014-60438-P, ESP2015-70646-C2-1-R, AYA2017-84185-P, ESP2017-83921-C2-1-R, AYA2017-90675-REDC (co-funded with EU FEDER funds), PGC2018-101814-B-I00, PID2019-110610RBC21, PID2020-120514GB-I00, IACA13-3E-2336, IACA15-BE3707, EQC2018-004918-P, the Severo Ochoa Programs SEV-2015- 0548 and CEX2019-000920-S, the Maria de Maeztu Program MDM2017-0765, and by the Consolider-Ingenio project CSD2010-00064 (EPI: Exploring the Physics of Inflation). We acknowledge support from the ACIISI, Consejeria de Economia, Conocimiento y Empleo del Gobierno de Canarias, and the European Regional Development Fund (ERDF) under grant with reference ProID2020010108. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement number 687312 (RADIOFOREGROUNDS). EdlH acknowledges financial support from the Concepcion´ Arenal Programme of the Universidad de Cantabria. DT acknowledges the support from the Chinese Academy of Sciences (CAS) President’s International Fellowship Initiative (PIFI) with grant no. 2020PM0042. FP acknowledges support from the Spanish State Research Agency (AEI) under grant number PID2019-105552RB-C43. The authors acknowledge the computer resources, technical expertise, and assistance provided by the Spanish Supercomputing Network (RES) node at Universidad de Cantabria. Some of the presented results are based on observations obtained with Planck (http://www.esa.int/Planck), an ESA science mission with instruments and contributions directly funded by ESA Member States, NASA, and Canada. We acknowledge the use of the Legacy Archive for Microwave Background Data Analysis (LAMBDA) and the Planck Legacy Archive (PLA). Support for LAMBDA is provided by the NASA Office of Space Science. Some of the results in this paper have been derived using the HEALPIX package (Gorski ´ et al. 2005), and the HEALPY (Zonca et al. 2019), NUMPY (Harris et al. 2020), EMCEE (ForemanMackey et al. 2013), and MATPLOTLIB (Hunter 2007) PYTHON packages

QUIJOTE scientific results - III. Microwave spectrum of intensity and polarization in the Taurus Molecular Cloud complex and L1527

ABSTRACT: We present new intensity and polarization observations of the Taurus Molecular Cloud (TMC) region in the frequency range 10–20 GHz with the multifrequency instrument (MFI) mounted on the first telescope of the Q-U-I-JOint TEnerife (QUIJOTE) experiment. From the combination of the QUIJOTE data with the WMAP 9-yr data release, the Planck second data release, the DIRBE maps, and ancillary data, we detect an anomalous microwave emission (AME) component with flux density SAME,peak = 43.0 ± 7.9 Jy in the TMC and SAME,peak = 10.7 ± 2.7 Jy in the dark cloud nebula L1527, which is part of the TMC. In the TMC the diffuse AME emission peaks around a frequency of 19 GHz, compared with an emission peak about a frequency of 25 GHz in L1527. In the TMC, the best constraint on the level of AME polarization is obtained at the Planck channel of 28.4 GHz, with an upper limit πAME < 4.2 per cent (95 per cent C.L.), which reduces to πAME < 3.8 per cent (95 per cent C.L.) if the intensity of all the free–free, synchrotron and thermal dust components are negligible at this frequency. The same analysis in L1527 leads to πAME < 5.3 per cent (95 per cent C.L.) or πAME < 4.5 per cent (95 per cent C.L.) under the same assumption. We find that in the TMC and L1527 on average about 80 per cent of the H II gas should be mixed with thermal dust. Our analysis shows how the QUIJOTE-MFI 10–20 GHz data provide key information to properly separate the synchrotron, free–free, and AME components.This work has been partially funded by the Spanish Ministry of Economy and Competitiveness (MINECO) under the projects AYA2007-68058-C03-01, AYA2010-21766-C03-02, AYA2012-39475-C02-01, AYA2014-60438-P: ESP2015- 70646.C2-1-R, AYA2015-64508-P and the Consolider-Ingenio project CSD2010-00064 (EPI: Exploring the Physics of Inflation)

Planck 2015 results. XXI. The integrated Sachs-Wolfe effect

Cosmology (including clusters of galaxies).-- et al.This paper presents a study of the integrated Sachs-Wolfe (ISW) effect from the Planck 2015 temperature and polarization data release. This secondary cosmic microwave background (CMB) anisotropy caused by the large-scale time-evolving gravitational potential is probed from different perspectives. The CMB is cross-correlated with different large-scale structure (LSS) tracers: radio sources from the NVSS catalogue; galaxies from the optical SDSS and the infrared WISE surveys; and the Planck 2015 convergence lensing map. The joint cross-correlation of the CMB with the tracers yields a detection at 4σ where most of the signal-to-noise is due to the Planck lensing and the NVSS radio catalogue. In fact, the ISW effect is detected from the Planck data only at ≈3σ (through the ISW-lensing bispectrum), which is similar to the detection level achieved by combining the cross-correlation signal coming from all the galaxy catalogues mentioned above. We study the ability of the ISW effect to place constraints on the dark-energy parameters; in particular, we show that ΩΛ is detected at more than 3σ. This cross-correlation analysis is performed only with the Planck temperature data, since the polarization scales available in the 2015 release do not permit significant improvement of the CMB-LSS cross-correlation detectability. Nevertheless, the Planck polarization data are used to study the anomalously large ISW signal previously reported through the aperture photometry on stacked CMB features at the locations of known superclusters and supervoids, which is in conflict with ΛCDM expectations. We find that the current Planck polarization data do not exclude that this signal could be caused by the ISW effect. In addition, the stacking of the Planck lensing map on the locations of superstructures exhibits a positive cross-correlation with these large-scale structures. Finally, we have improved our previous reconstruction of the ISW temperature fluctuations by combining the information encoded in all the previously mentioned LSS tracers. In particular, we construct a map of the ISW secondary anisotropies and the corresponding uncertainties map, obtained from simulations. We also explore the reconstruction of the ISW anisotropies caused by the large-scale structure traced by the 2MASS Photometric Redshift Survey (2MPZ) by directly inverting the density field into the gravitational potential field.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).Peer Reviewe

Cosmological analyses with primordial non-Gaussianity and weak lensing magnification

Memoria presentada para optar al título de Doctor otorgado por la Universidad de Cantabria por Biuse Casaponsa Galí y que ha sido realizada en el Instituto de Física de Cantabria.[ES]: Durante las últimas décadas, las grandes colaboraciones, la innovación tecnológica y una dosis de creatividad han permitido que el conocimiento del Universo creciera considerablemente, dando lugar a un modelo estándar para explicar el contenido del Universo y su evolución. Las observaciones de alta precisión han sido y serán muy importantes para obtener una imagen detallada del Universo. Gran parte de la información cosmológica ha sido obtenida del estudio del fondo cósmico de microondas, de la estructura a gran escala y supernovas de tipo Ia. Durante los próximos años, se espera obtener información valiosa de observaciones del efecto lente débil, oscilaciones acústicas de bariones y de la polarización del fondo cósmico de microondas. Este tesis se centra en dos de estos temas, el fondo cósmico de microondas y el efecto lente débil. El objetivo de esta tesis es contribuir con nuevas herramientas al análisis de estos observables para obtener la mayor información posible de una manera simple y computacionalmente eficiente.[EN]: During the past few decades, large collaborations, technology innovation and a dose of creativity has led the knowledge of our Universe to grow considerably, giving rise to a standard model to explain the Universe content and evolution. The high precision cosmological observations have been and will be very important to obtain a detailed picture of our Universe. The most notable cosmological information has been obtained from the cosmic microwave background (CMB), large scale structure distribution and supernovae Ia observations. During the next years the cosmological history should be continued with observations of weak lensing, baryonic acoustic oscillations and CMB polarization surveys, among other probes. The PhD thesis presented here is focused on two of these topics, CMB and weak lensing. for future experiments are very The aim of this thesis is to contribute with new tools to the analysis of those observables in order to extract the largest amount of information possible in a simple and computationally efficient way.Primero de todo, y aunque no esté de moda, me gustaría empezar por agradecer al Gobierno de España, por las becas recibidas al estudiar la licenciatura de física, porque cuando tienes pocos recursos, pagar las matrículas académicas no es fácil. También por ofrecer becas FPI, de la que he sido beneficiaria, y que me ha permitido formarme como investigadora cobrando un sueldo y cotizando. Por ofrecer estancias breves en centros extranjeros, donde he colaborado con expertos cosmólogos reconocidos internacionalmente. Gracias por todos estos recursos destinados a formarme como investigadora y espero que nuevos jóvenes estudiantes puedan seguir gozando de estos esfuerzos, si se desea apostar por la investigación.Peer Reviewe

Cosmological analyses with primordial non-Gaussianity and weak lensing magnification

Resumen: Durante las últimas décadas, las grandes colaboraciones, la innovación tecnológica y una dosis de creatividad han permitido que el conocimiento del Universo creciera considerablemente, dando lugar a un modelo estándar para explicar el contenido del Universo y su evolución. Las observaciones de alta precisión han sido y serán muy importantes para obtener una imagen detallada del Universo. Gran parte de la información cosmológica ha sido obtenida del estudio del fondo cósmico de microondas, de la estructura a gran escala y supernovas de tipo Ia. Durante los próximos años, se espera obtener información valiosa de observaciones del efecto lente débil, oscilaciones acústicas de bariones y de la polarización del fondo cósmico de microondas. Este tesis se centra en dos de estos temas, el fondo cósmico de microondas y el efecto lente débil. El objetivo de esta tesis es contribuir con nuevas herramientas al análisis de estos observables para obtener la mayor información posible de una manera simple y computacionalmente eficiente.Abstract: During the past few decades, large collaborations, technology innovation and a dose of creativity has led the knowledge of our Universe to grow considerably, giving rise to a standard model to explain the Universe content and evolution. The high precision cosmological observations have been and will be very important to obtain a detailed picture of our Universe. The most notable cosmological information has been obtained from the cosmic microwave background (CMB), large scale structure distribution and supernovae Ia observations. During the next years the cosmological history should be continued with observations of weak lensing, baryonic acoustic oscillations and CMB polarization surveys, among other probes. The PhD thesis presented here is focused on two of these topics, CMB and weak lensing. for future experiments are very The aim of this thesis is to contribute with new tools to the analysis of those observables in order to extract the largest amount of information possible in a simple and computationally efficient way

Exploring local fNL estimators based on the binned bispectrum

We explore different estimators of the local non-linear coupling parameter, fNL, based on the binned bispectrum presented in Bucher et al. Using simulations of Wilkinson Microwave Anisotropy Probe (WMAP)-7-year data, we compare the performance of a regression neural network with a Χ2-minimization and study the dependence of the results on the presence of the linear term in the analysis and on the use of inpainting for masked regions. Both methods obtain similar results and are robust to the use of inpainting, but the neural network estimator converges considerably faster. We also examine the performance of a simplified Χ2 estimator that assumes a diagonal matrix and has the linear term subtracted, which considerably reduces the computational time; in this case inpainting is found to be crucial. The estimators are also applied to real WMAP-7-year data, yielding constraints at 95 per cent confidence level of-3< fNL < 83. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.We acknowledge partial financial support from the Spanish Ministerio de Ciencia e Innovación project AYA2007-68058-C03-02 and AYA2010-21766-C03-01. We also acknowledge partial financial support from the Spanish Minsterio de Economía y Competitividad AYA2010-21766-C03-01 and Consolider- Ingenio 2010 CSD2010- 00064 projects. BC thanks the Spanish Ministerio de Ciencia e Innovación for a pre-doctoral fellowship.Peer Reviewe