Modeling Dust and Starlight in Galaxies Observed by Spitzer and Herschel: The KINGFISH Sample

Interstellar dust and starlight are modeled for the galaxies of the project "Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel." The galaxies were observed by the Infrared Array Camera and the Multiband Imaging Photometer for Spitzer on Spitzer Space Telescope, and the Photodetector Array Camera and Spectrometer and the Spectral and Photometric Imaging Receiver on Herschel Space Observatory. With data from 3.6 to 500 μm, dust models are strongly constrained. Using a physical dust model, for each pixel in each galaxy we estimate (1) dust surface density, (2) dust mass fraction in polycyclic aromatic hydrocarbons (PAHs), (3) distribution of starlight intensities heating the dust, (4) total infrared (IR) luminosity emitted by the dust, and (5) IR luminosity originating in subregions with high starlight intensity. The dust models successfully reproduce the observed global and resolved spectral energy distributions. With the angular resolution of Herschel, we obtain well-resolved maps (available online) for the dust properties. As in previous studies, we find the PAH fraction q_(PAH) to be an increasing function of metallicity, with a threshold oxygen abundance Z/Z⊙ ≈ 0.1, but we find the data to be fitted best with q_(PAH) increasing linearly with log(O/H) above a threshold value of 0.15(O/H)⊙. We obtain total dust masses for each galaxy by summing the dust mass over the individual map pixels; these "resolved" dust masses are consistent with the masses inferred from a model fit to the global photometry. The global dust-to-gas ratios obtained from this study are found to correlate with galaxy metallicities. Systems with Z/Z⊙ ≳ 0.5 have most of their refractory elements locked up in dust, whereas in systems with Z/Z⊙ ≾ 0.3 most of these elements tend to remain in the gas phase. Within galaxies, we find that q_(PAH) is suppressed in regions with unusually warm dust with vL_v(70 μm) ≳ 0.4L_(dust). With knowledge of one long-wavelength flux density ratio (e.g., f₁₆₀/f₅₀₀), the minimum starlight intensity heating the dust (U_(min)) can be estimated to within ~50%, despite a variation in U_(min) of more than two orders of magnitude. For the adopted dust model, dust masses can be estimated to within ~0.2 dex accuracy using the f₁₆₀/f₅₀₀ flux ratio and the integrated dust luminosity, and to ~0.07 dex accuracy using the 500 μm luminosity vL_v(500 µm) alone. There are additional systematic errors arising from the choice of dust model, but these are hard to estimate. These calibrated prescriptions for estimating starlight heating intensity and dust mass may be useful for studies of high-redshift galaxies

Common-Resolution Convolution Kernels for Space- and Ground-Based Telescopes

Multi-wavelength study of extended astronomical objects requires combining images from instruments with differing point spread functions (PSFs). We describe the construction of convolution kernels that allow one to generate (multi-wavelength) images with a common PSF, thus preserving the colors of the astronomical sources. We generate convolution kernels for the cameras of the Spitzer Space Telescope, Herschel Space Observatory, Galaxy Evolution Explorer (GALEX), Wide-field Infrared Survey Explorer (WISE), ground-based optical telescopes (Moffat functions and sum of Gaussians), and Gaussian PSFs. These kernels allow the study of the Spectral Energy Distribution (SED) of extended objects, preserving the characteristic SED in each pixel. The convolution kernels and the IDL packages used to construct and use them are made publicly available

Modeling Dust and Starlight in Galaxies Observed by Spitzer and Herschel: The KINGFISH Sample

Interstellar dust and starlight are modeled for the galaxies of the project “Key Insights on Nearby Galaxies: A FarInfrared Survey with Herschel.” The galaxies were observed by the Infrared Array Camera and the Multiband Imaging Photometer for Spitzer on Spitzer Space Telescope, and the Photodetector Array Camera and Spectrometer and the Spectral and Photometric Imaging Receiver on Herschel Space Observatory. With data from 3.6 to 500 μm, dust models are strongly constrained. Using a physical dust model, for each pixel in each galaxy we estimate (1) dust surface density, (2) dust mass fraction in polycyclic aromatic hydrocarbons (PAHs), (3) distribution of starlight intensities heating the dust, (4) total infrared (IR) luminosity emitted by the dust, and (5) IR luminosity originating in subregions with high starlight intensity. The dust models successfully reproduce the observed global and resolved spectral energy distributions. With the angular resolution of Herschel, we obtain well-resolved maps (available online) for the dust properties. As in previous studies, we find the PAH fraction qPAH to be an increasing function of metallicity, with a threshold oxygen abundance Z/Ze ≈ 0.1, but we find the data to be fitted best with qPAH increasing linearly with log O H ( ) above a threshold value of 0.15(O/H)e. We obtain total dust masses for each galaxy by summing the dust mass over the individual map pixels; these “resolved” dust masses are consistent with the masses inferred from a model fit to the global photometry. The global dust-to-gas ratios obtained from this study are found to correlate with galaxy metallicities. Systems with Z/Ze 0.5 have most of their refractory elements locked up in dust, whereas in systems with Z/Ze 0.3 most of these elements tend to remain in the gas phase. Within galaxies, we find that qPAH is suppressed in regions with unusually warm dust with nL L n ( ) 70 m 0.4 m dust. With knowledge of one long-wavelength flux density ratio (e.g., f160/f500), the minimum starlight intensity heating the dust (Umin) can be estimated to within ∼50%, despite a variation in Umin of more than two orders of magnitude. For the adopted dust model, dust masses can be estimated to within ∼0.2 dex accuracy using the f160/f500 flux ratio and the integrated dust luminosity, and to ∼0.07 dex accuracy using the 500 μm luminosity nLn ( ) 500 mm alone. There are additional systematic errors arising from the choice of dust model, but these are hard to estimate. These calibrated prescriptions for estimating starlight heating intensity and dust mass may be useful for studies of high-redshift galaxies

Plan de viabilidad empresa exportaciones de apoyo al sector vinícola leonés

Con motivo del proyecto de fin de carrera de ‘Grado en Administración y Dirección de Empresas’ se ha propuesto realizar un estudio de la viabilidad, y la posible creación y puesta en marcha de una empresa de exportaciones asociada a productores de un importante y conocido gremio leonés. Gracias a esta idea de negocio, apoyaremos a pequeñas pymes con recursos económicos y conocimientos limitados, actualmente en dificultades para sacar al mercado su producción. De esta manera potenciaremos su negocio bajo una pequeña inversión rápidamente recuperable. Además, bajo la motivación anterior, comprobaremos que la inversión inicial de nuestra empresa es realmente saneable en un periodo no superior a dos años. Para ello, se proponen una serie de estrategias muy ligadas al comercio internacional, la logística y distribución del producto. De la misma manera, se han analizado los posibles problemas que podría conllevar la puesta en marcha de la empresa y como explotar las posibles oportunidades. Por último, también se ha proyectado un ‘Business plan’ a 5 años, dónde se propone una inversión inicial para concluir con un proyecto empresarial atractivo y sobre todo rentable para el posible inverso

The Chronic Social-employment Precariousness of the Canary Islands

En las tres últimas décadas, Canarias ha logrado insertarse en los selectos circuitos de la globalización económica. Actividad turística, movimientos migratorios, comercio internacional, inversiones públicas y privadas y avance tecnológico son, básicamente, las fuerzas que señalan la globalización de Canarias. Sin embargo, la evolución del empleo y de las condiciones sociales de vida no expresa un desarrollo tan satisfactorio. En este artículo analizamos las causas principales que subyacen en el proceso crónico de precariedad sociolaboral de Canarias. En la primera parte, nos detenemos en el sistema productivo, para resaltar las deficiencias más evidentes de la oferta económica. En la segunda parte, analizamos los efectos sociales que retroalimentan el deterioro: la pobreza, el desempleo masivo y la precariedad salarial.In the three last decades, the Canary Islands have managed to be inserted in the select circuits of the economic globalization. Tourist activity, migratory movements, international trade, public and private investments, and technological advance is, basically, the forces that indicate the globalization of the Canary Islands. Nevertheless, the evolution of the work and the social conditions of life does not express a so satisfactory development. In this article we analyzed the leading causes that underlie in the continuous process of precarious work of the Canary Islands. In the first part, we pause in the productive system, to emphasize the most evidence deficiencies of the economic supply. In the second part, we analyzed the social effects that feed back the deterioration: the poverty, mass unemployment, and low wage

Dust models post-Planck: constraining the far-infrared opacity of dust in the diffuse interstellar medium

We compare the performance of several dust models in reproducing the dust spectral energy distribution (SED) per unit extinction in the diffuse interstellar medium (ISM). We use our results to constrain the variability of the optical properties of big grains in the diffuse ISM, as published by the Planck collaboration. We use two different techniques to compare the predictions of dust models to data from the Planck HFI, IRAS and SDSS surveys. First, we fit the far-infrared emission spectrum to recover the dust extinction and the intensity of the interstellar radiation field (ISRF). Second, we infer the ISRF intensity from the total power emitted by dust per unit extinction, and then predict the emission spectrum. In both cases, we test the ability of the models to reproduce dust emission and extinction at the same time. We identify two issues. Not all models can reproduce the average dust emission per unit extinction: there are differences of up to a factor $\sim2$ between models, and the best accord between model and observation is obtained with the more emissive grains derived from recent laboratory data on silicates and amorphous carbons. All models fail to reproduce the variations in the emission per unit extinction if the only variable parameter is the ISRF intensity: this confirms that the optical properties of dust are indeed variable in the diffuse ISM. Diffuse ISM observations are consistent with a scenario where both ISRF intensity and dust optical properties vary. The ratio of the far-infrared opacity to the $V$ band extinction cross-section presents variations of the order of $\sim20\%$ ($40-50\%$ in extreme cases), while ISRF intensity varies by $\sim30\%$ ($\sim60\%$ in extreme cases). This must be accounted for in future modelling.Comment: A&A, in pres

Poly(arylene Ether Sulfones): Synthesis, Modifications and Applications.

Poly(arylene ether sulfones) were synthesized by aromatic nucleophilic polymerization of the monomers; 4,4\sp\prime-biphenol, 4-chlorophenyl sulfone, hydroquinone, and tert-butylhydroquinone. Different conditions of temperature and solvent systems were used to determine the best synthetic approaches for the preparation of poly-(4,4\sp\prime-biphenol/4-chlorophenyl sulfone) (1:1), poly-(4-4\sp\prime-biphenol/4-chlorophenyl sulfone/hydroquinone) (1:2:1), and poly (4-4\sp\prime-biphenol/4-chlorophenyl sulfone/tert-butylhydroquinone) (1:2:1). The use of aprotic high boiling solvent mixtures of N-methyl-2-pyrrolidone (NMP), and N-cyclohexyl-2-pyrrolidone (CHP), facilitated the formation of polymers with structures which can easily be controlled by varying the ratio of monomers, and by varying the concentration of reactants. The polymers were functionalized and modified by silylation, amination and aminomethylation. Directed silylation by electrophilic substitution ortho to the ether group was effected by bromination, followed by lithiation with butyllithium before quenching with chlorotrimethyl-silane. Silylation ortho to the sulfonyl group was effected by metal hydrogen exchange with butyllithium before quenching with chlorotrimethysilane. A maximum of two trimethylsilyl substituents can be introduced for every repeat unit. Modification by amination was accomplished by the introduction of a nitro group and subsequent reduction of the nitro group to an amine. Sodium dithionite was more effective than sulfur/sodium borohydride, or titanium tetrachloride/lithium aluminum hydride as a reducing agent. Degrees of functionalization up to 2 amino groups per repeat unit were achieved. Aminomethylation was performed in a two step process. The first step involved introduction of an N-methylphthalimide substituent by condensation of the activated arylene repeat units with N-hydroxymethyl-phthalimide in the presence of a highly protic solvent mixture, trifluoroacetic acid and trifluoromethanesulfonic acid. The second step involved hydrazinolysis to cleave the phthalimide group and to release aminomethyl substituents. The polymers and their functionalized derivatives were characterized by \sp1H and \sp{13}C NMR, infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and viscosity measurements. \sp{13}C NMR chemical shifts calculated from additivity rule were compared with the assigned chemical shifts. The spectroscopic results are consistent with the assigned structures. The glass transition temperatures (Tg) of the polymers were compared with predicted values based upon molar additivity of incremental values for the structural units. As predicted, tert-butyl substituents raised the Tg while introduction of the more flexible trimethylsilyl groups reduced the Tg\u27s compared to unsubstituted polymers

Experiencias formativas en el área de conocimiento artístico en la carrera Maestro en Primera Infancia

El presente trabajo de investigación tuvo como propósito profundizar en las experiencias formativas en el área de Conocimiento Artístico llevadas a cabo por las estudiantes que transitan por la Carrera Maestro en Primera Infancia del Consejo de Formación en Educación. La decisión se basó en que muchas veces las prácticas educativas perpetúan técnicas, modelos y estrategias, dificultando así propuestas innovadoras que impliquen contemplar ideas, experiencia o nuevos paradigmas. Al contar con una carrera novel con especificidad en la Primera Infancia se consideró importante observar los procesos llevados a cabo por las estudiantes y visualizar las construcciones sobre la enseñanza; es decir, las apropiaciones, prácticas, experiencias, transferencias y confianza en las formas de enseñar. Los trayectos fueron observados utilizando una metodología que integró la encuesta a estudiantes en diferentes momentos de la cursada, la observación participante y la entrevista en profundidad. Se utilizaron además aspectos de la investigación artística por el valor que la misma puede aportar al tema. Se integró en ella la etnografía visual ya que permite el análisis de los productos artísticos realizados por los niños y planificados por las estudiantes. Al finalizar se plantearon aportes para continuar pensando aspectos sustanciales como la interdisciplinariedad, el valor del arte en el proceso formativo y la importancia de la experiencia