A Bayesian method for point source polarization estimation

The estimation of the polarization $P$ of extragalactic compact sources in Cosmic Microwave Background images is a very important task in order to clean these images for cosmological purposes -- as, for example, to constrain the tensor-to-scalar ratio of primordial fluctuations during inflation -- and also to obtain relevant astrophysical information about the compact sources themselves in a frequency range, $\nu \sim 10$--$200$ GHz, where observations have only very recently started to be available. In this paper we propose a Bayesian maximum a posteriori (MAP) approach estimation scheme which incorporates prior information about the distribution of the polarization fraction of extragalactic compact sources between 1 and 100 GHz. We apply this Bayesian scheme to white noise simulations and to more realistic simulations that include CMB intensity, Galactic foregrounds and instrumental noise with the characteristics of the QUIJOTE experiment Wide Survey at 11 GHz. Using these simulations, we also compare our Bayesian method with the frequentist Filtered Fusion method that has been already used in WMAP data and in the \emph{Planck} mission. We find that the Bayesian method allows us to decrease the threshold for a feasible estimation of $P$ to levels below $\sim 100$ mJy (as compared to $\sim 500$ mJy that was the equivalent threshold for the frequentist Filtered Fusion). We compare the bias introduced by the Bayesian method and find it to be small in absolute terms. Finally, we test the robustness of the Bayesian estimator against uncertainties in the prior and in the flux density of the sources. We find that the Bayesian estimator is robust against moderate changes in the parameters of the prior and almost insensitive to realistic errors in the estimated photometry of the sources.Comment: 15 pages, 12 figures, submitted to A&

Contribución al estudio de los hongos que fructifican sobre la familia Pinaceae (Gen. Pinus L.) en Espana (1ª aportación)

In order to determine wether there is any specific group of fungi able to fructify on plant debris from the genus Pinas L., a Sheme of work was made, introducing new signs for it. 8 new taxons are described, being a contribution to the spanish mycological catalogue. The presence in Spain of Ascobolus archeri formely known only in Tasmania (Australia) should be pointed out.Se realiza un ensayo de trabajo para determinar ciertos grupos de hongos específicos o que muestren apetencia a fructificar sobre restos vegetales del género Pinus, introduciendo signos determinados para estos estudios. Resultan nuevas aportaciones al catálogo micológico español los ocho siguientes tazones: Ascobolus arcberi, Coniophorella olivacea, Oidium candicans, Hypboderma argillaceum, Hypboderma pallidum, Hipochnicium eichleri, Galerina autumnalis y Galerina stylifera. De las cuales Ascobolus archeries nueva cita para Europa

Sphaerosporella brunnea (Alb. et Schwein.) Svrcek et Kubicka, un discomicete con incidencia en la truficultura e interés forestal

Sphaerosporella brunnea (Alb. et Schwein.) Svrcek et Kubicka, a cup-shaped ascomycete related with truffle cultures and afforestation. A casual finding of Sphaerosporella brunnea in some greenhouses from Spain, growing in connection with several ectomycorrhizal plants, is reported. These plants were experimentally inoculated with low level inoculum of Tuber melanosporum. Sphaerosporella brunnea is described and illustrated, and its negative role in truffle cultures and its possible utilization in burned are as recovery is emphasized.Se da cuenta del hallazgo casual, en unos viveros españoles de Sphaerosporella brunnea, formando micorrizas con plantas diversas, las cuales habían sido inoculadas experimentalmente con niveles bajos de Tuber melanosporum. Se describe e ilustra esta especie, al tiempo que se destaca su papel negativo en la truficultura y su posible utilización en la recuperación de áreas incendiadas

Sphaerosporella brunnea (Alb. et Schwein.) Svrcek et Kubicka, un discomicete con incidencia en la truficultura e interés forestal

Se da cuenta del hallazgo casual, en unos viveros españoles de Sphaerosporella brunnea, formando micorrizas con plantas diversas, las cuales habían sido inoculadas experimentalmente con niveles bajos de Tuber melanosporum. Se describe e ilustra esta especie, al tiempo que se destaca su papel negativo en la truficultura y su posible utilización en la recuperación de áreas incendiadas.Sphaerosporella brunnea (Alb. et Schwein.) Svrcek et Kubicka, a cup-shaped ascomycete related with truffle cultures and afforestation. A casual finding of Sphaerosporella brunnea in some greenhouses from Spain, growing in connection with several ectomycorrhizal plants, is reported. These plants were experimentally inoculated with low level inoculum of Tuber melanosporum. Sphaerosporella brunnea is described and illustrated, and its negative role in truffle cultures and its possible utilization in burned are as recovery is emphasized

Elemental (im-)miscibility determines phase formation of multinary nanoparticles co-sputtered in ionic liquids

Non-equilibrium synthesis methods allow to alloy bulk-immiscible elements into multinary nanoparticles, which broadens the design space for new materials.Whereas sputtering onto solid substrates can combine immiscible elements into thin film solid solutions, this is not clear for sputtering of nanoparticles in ionicliquids. Thus, the suitability of sputtering in ionic liquids for producing nanoparticles of immiscible elements is investigated by co-sputtering the systems Au-Cu (miscible), Au-Ru and Cu-Ru (both immiscible), and Au-Cu-Ru on the surface of the ionic liquid 1-butyl-3-methylimidazolium bis-trifluoromethylsulfonyl)imide [Bmim][(Tf)2N]. The sputtered nanoparticles were analyzed to obtain (i) knowledge concerning the general formation process ofnanoparticles when sputtering onto ionic liquid surfaces and (ii) information, if alloy nanoparticles of immiscible elements can be synthesized as well as (iii)evidence if the Hume-Rothery rules for solid solubility are valid for sputtered nanoparticles. Accompanying atomistic simulations using density-functional theoryfor clusters of different size and ordering confirm that the miscibility of Au-Cu and the immiscibility of Au-Ru and Cu-Ru govern the thermodynamic stabilityof the nanoparticles. Based on the matching experimental and theoretical results for the NP/IL-systems concerning NP stability, a formation model of multinaryNPs in ILs was developed

The evolution of H{\sc ii} galaxies: Testing the bursting scenario through the use of self-consistent models

We have computed a series of realistic and self-consistent models of the emitted spectra of H{\sc ii} galaxies. Our models combine different codes of chemical evolution, evolutionary population synthesis and photoionization. The emitted spectrum of H{\sc ii} galaxies is reproduced by means of the photoionization code CLOUDY, using as ionizing spectrum the spectral energy distribution of the modelled H{\sc ii} galaxy, which in turn is calculated according to a Star Formation History (SFH) and a metallicity evolution given by a chemical evolution model that follows the abundances of 15 different elements. The contribution of emission lines to the broad-band colours is explicitly taken into account. The results of our code are compared with photometric and spectroscopic data of H{\sc ii} galaxies. Our technique reproduces observed diagnostic diagrams, abundances, equivalent width-colour and equivalent width-metallicity relations for local H{\sc ii} galaxies.Comment: 13 figures and 2 tables, accepted for publication in MNRAS Main Journa

Zircon to monazite phase transition in CeVO4

X-ray diffraction and Raman-scattering measurements on cerium vanadate have been performed up to 12 and 16 GPa, respectively. Experiments reveal that at 5.3 GPa the onset of a pressure-induced irreversible phase transition from the zircon to the monazite structure. Beyond this pressure, diffraction peaks and Raman-active modes of the monazite phase are measured. The zircon to monazite transition in CeVO4 is distinctive among the other rare-earth orthovanadates. We also observed softening of external translational Eg and internal B2g bending modes. We attributed it to mechanical instabilities of zircon phase against the pressure-induced distortion. We additionally report lattice-dynamical and total-energy calculations which are in agreement with the experimental results. Finally, the effect of non-hydrostatic stresses on the structural sequence is studied and the equations of state of different phases are reported.Comment: 45 pages, 8 figures, 8 table