Inner and outer star forming regions over the disks of spiral galaxies. I. Sample characterization

Context. The knowledge of abundance distributions is central to understanding the formation and evolution of galaxies. Most of the relations employed for the derivation of gas abundances have so far been derived from observations of outer disk HII regions, despite the known differences between inner and outer regions. Aims. Using integral field spectroscopy (IFS) observations we aim to perform a systematic study and comparison of two inner and outer HII regions samples. The spatial resolution of the IFS, the number of objects and the homogeneity and coherence of the observations allow a complete characterization of the main observational properties and differences of the regions. Methods. We analyzed a sample of 725 inner HII regions and a sample of 671 outer HII regions, all of them detected and extracted from the observations of a sample of 263 nearby, isolated, spiral galaxies observed by the CALIFA survey. Results. We find that inner HII regions show smaller equivalent widths, greater extinction and luminosities, along with greater values of [NII]{\lambda}6583/H{\alpha} and [OII]{\lambda}3727/[OIII]{\lambda}5007 emission-line ratios, indicating higher metallicites and lower ionization parameters. Inner regions have also redder colors and higher photometric and ionizing masses, although Mion/Mphot is slighty higher for the outer regions. Conclusions. This work shows important observational differences between inner and outer HII regions in star forming galaxies not previously studied in detail. These differences indicate that inner regions have more evolved stellar populations and are in a later evolution state with respect to outer regions, which goes in line with the inside-out galaxy formation paradigm.Comment: 16 page

Papel de los esfingolipidos en la senalizacion celular

Este trabajo ha recibido financiación del Ministerio de Educación\ud y Ciencia (SAF-2005-00602

Dynamics of a suspension of interacting yolk-shell particles

In this work we study the self-diffusion properties of a liquid of hollow spherical particles (shells)bearing a smaller solid sphere in their interior (yolks). We model this system using purely repulsive hard-body interactions between all (shell and yolk) particles, but assume the presence of a background ideal solvent such that all the particles execute free Brownian motion between collisions,characterized by short-time self-diffusion coefficients D0s for the shells and D0y for the yolks. Using a softened version of these interparticle potentials we perform Brownian dynamics simulations to determine the mean squared displacement and intermediate scattering function of the yolk-shell complex. These results can be understood in terms of a set of effective Langevin equations for the N interacting shell particles, pre-averaged over the yolks' degrees of freedom, from which an approximate self-consistent description of the simulated self-diffusion properties can be derived. Here we compare the theoretical and simulated results between them, and with the results for the same system in the absence of yolks. We find that the yolks, which have no effect on the shell-shell static structure, influence the dynamic properties in a predictable manner, fully captured by the theory.Comment: 5 pages, 1 figur

Non-ergodic effects in the Coulomb glass: specific heat

We present a numerical method for the investigation of non-ergodic effects in the Coulomb glass. For that, an almost complete set of low-energy many-particle states is obtained by a new algorithm. The dynamics of the sample is mapped to the graph formed by the relevant transitions between these states, that means by transitions with rates larger than the inverse of the duration of the measurement. The formation of isolated clusters in the graph indicates non-ergodicity. We analyze the connectivity of this graph in dependence on temperature, duration of measurement, degree of disorder, and dimensionality, studying how non-ergodicity is reflected in the specific heat.Comment: Submited Phys. Rev.

Estudio de la influencia de la calidad del agua de riego sobre las propiedades bioquímicas del suelo

Trabajo presentado en el VII Simposio Nacional sobre Control de la Degradación y Restauración de Suelos, celebrado en Bilbao, España, del 23 al 26 de junio de 2015Este estudio analiza la influencia de la calidad del agua de riego sobre los parámetros bioquímicos de los Fluvisoles calcáricos representativos en dos zonas del sur de Alicante. Mediante un análisis de componentes principales (ACP) se obtuvo el PC1 (40% variabilidad), referente a la salinidad, siendo útil para diferenciar ambas zonas de estudio, y el PC2 (31%), englobando los parámetros bioquímicos, que distingue las muestras en función de la profundidad. Sin embargo, no se ha observado un efecto negativo sobre las principales actividades enzimáticas en el área más afectada por la salinización.Peer Reviewe

Spatially resolved star formation main sequence of galaxies in the CALIFA survey

Astrophysical Journal Letters 821.2 (2016): L26 reproduced by permission of the AASThe "main sequence of galaxies" - defined in terms of the total star formation rate ψ versus the total stellar mass M∗ - is a well-studied tight relation that has been observed at several wavelengths and at different redshifts. All earlier studies have derived this relation from integrated properties of galaxies. We recover the same relation from an analysis of spatially resolved properties, with integral field spectroscopic (IFS) observations of 306 galaxies from the CALIFA survey. We consider the SFR surface density in units of log (Mo yr-1 Kpc-2) and the stellar mass surface density in units of log (Mo Kpc-2) in individual spaxels that probe spatial scales of 0.5-1.5 Kpc. This local relation exhibits a high degree of correlation with small scatter (σ = 0.23 dex), irrespective of the dominant ionization source of the host galaxy or its integrated stellar mass. We highlight (i) the integrated star formation main sequence formed by galaxies whose dominant ionization process is related to star formation, for which we find a slope of 0.81 ± 0.02; (ii) for the spatially resolved relation obtained with the spaxel analysis, we find a slope of 0.72 ± 0.04; and (iii) for the integrated main sequence, we also identified a sequence formed by galaxies that are dominated by an old stellar population, which we have called the retired galaxies sequenceFinancial support: M.C.D. and S.F.S.: DGAPA-UNAM funding; CONACyT-180125 and PAPIIT IA- 100815 projects. Z.S.: EU Marie Curie Career Integration Grant ”SteMaGE” PCIG12-GA-2012-326466. Y.A.: RyC- 2011-09461 and AYA2013-47742-C4-3-P projects from the Spanish MINECO and the SELGIFS programme, funded by the EU (FP7-PEOPLE-2013-IRSES-612701). C.J.W.: Marie Curie Career Integration Grant 303912. R.M.G.D.: AyA2014- 57490-P and J.A. P12-FQM2828 grants. J.F.B.: AYA2013- 48226-C3-1-P from the Spanish MINECO grant. L.G.: Millennium Science Initiative through grant IC120009, and by CONICYT through FONDECYT grant 314056

Poetry-Panting. Frederic Amat’s Interview

Frederic Amat nació en 1952, su trabajo ha sido expuesto en todo el mundo y se ha convertido en una referencia del arte contemporáneo. Pocos artistas muestran como él el carácter interdisciplinar del arte actual y cómo todos los medios expresivos están en contacto continuo y plena transformación. Su trabajo desde la pintura, desde el videoarte, la escenografía o la cinematografía, hace imposible su clasificación. La entrevista que presentamos (mayo-junio del 2011) se centra en cómo Frederic Amat aborda en su obra las relaciones entre artes, entre literatura y pintura. A través de sus respuestas nos va desvelando con la palabra su comprensión de las relaciones inter-artísticas y su visión del arte, más allá de fronteras o medios expresivos. Comparte su experiencia como lector con nosotros y nos muestra con la palabra su vivencia de pintor. Frederic Amat respondió a nuestras preguntas desde su propia experimentación de las relaciones entre artes, con una sinceridad que solo puede partir desde la emoción de esa vivencia. Este hecho convierte esta entrevista en un auténtico lujo y en un privilegio en sus dos vertientes principales: en el placer su lectura, y en el inestimable valor para el estudio e investigación de las relaciones entre artes.Frederic Amat (1952) is a international reference in contemporary art. His interdisciplinary work shows how expressive means are in continuous change and transformation. His work, from painting to video, scenography or cinematography, is not classifiable. This interview (may 2011) is focused on the way Frederic Amat uses the relation between literature and painting in his work, in how he approaches the relationship between different arts. He gives us the clue to his understanding of inter-artistic relations and his general view of art, an art with no barriers. He shares with us his experience as a reader and he shows us his living as a painter. He answered our questions from his own experience relating different arts, with the truth that grows from the emotion of feeling. This is not only an invaluable document in the study and research of the relation between arts but also a pleasure to read; It is, thus, a luxury and a privilege to have had the opportunity to talk to make this interview

Dielectric susceptibility of the Coulomb-glass

We derive a microscopic expression for the dielectric susceptibility $\chi$ of a Coulomb glass, which corresponds to the definition used in classical electrodynamics, the derivative of the polarization with respect to the electric field. The fluctuation-dissipation theorem tells us that $\chi$ is a function of the thermal fluctuations of the dipole moment of the system. We calculate $\chi$ numerically for three-dimensional Coulomb glasses as a function of temperature and frequency