27 research outputs found

    Estratexia Europa 2020: Obxectivo pobreza

    Get PDF
    Traballo Fin de Grao Administración e Dirección de EmpresasO presente Traballo de Fin de Grao, que consta de 9.997 palabras, estuda o obxectivo pobreza encadrado na Estratexia Europa 2020. Dende os anos 70 do século XX, as institucións europeas foron aplicando diferentes plans de loita contra a pobreza até a actual estratexia desta década, a cal procura un crecemento “intelixente, sostible e integrador”. Os cinco principais obxectivos da Europa 2020, entre os que se atopa rescatar da pobreza a máis de 20 millóns de persoas en comparación co ano 2008, están complementados cunha serie de mecanismos de control tanto a nivel europeo como nacional. Para medir o obxectivo pobreza, Europa 2020 utiliza un indicador multidimensional produto da transformación que experimentou ao longo das décadas a definición de pobreza: a taxa AROPE. Este indicador ten en conta os seguintes tres factores: risco de pobreza, privación material severa e baixa intensidade laboral do fogar..

    Factors that intervene in the learning of the lecto-escritura in children and girls of Tasajera

    Get PDF
    La presente investigación tuvo como objetivo Identificar los factores que intervienen en el aprendizaje de la lectoescritura en los niños y niñas de cuarto grado pertenecientes a la Institución Educativa Departamental Rural de Tasajera, jornada mañana sede número 2, La Gloria. El desarrollo del estudio se enmarcó en un diseño no experimental de tipo descriptivo, en el cual se observa el fenómeno tal y como se presenta en su ámbito natural para su posterior análisis, sin manipular intencionalmente sus variables, y se contextualizo en un estudio Transeccional donde los datos se recolectan en un único momento. Como técnica de recolección de información se utilizó la encuesta y como instrumento se aplicó un cuestionario y cuatro actividades pedagógicas. Como conclusiones se hace necesario desarrollar por el docente estrategias que promuevan el reforzamiento de los procesos que intervienen en el aprendizaje de la lecto-escritura, involucrando a toda la comunidad educativa.The objective of this research was to identify the factors that intervene in the learning of literacy in the fourth grade boys and girls belonging to the Rural Departmental Educational Institution of Tasajera, tomorrow morning, venue number 2, La Gloria. The development of the study was framed in a non-experimental design of descriptive type, in which the phenomenon is observed as it is presented in its natural environment for subsequent analysis, without intentionally manipulating its variables, and contextualized in a Transectional study where the data is collected in a single moment. As a technique for collecting information, the survey was used and a questionnaire and four pedagogical activities were applied as an instrument. As conclusions, it is necessary to develop by the teacher strategies that promote the reinforcement of the processes that intervene in the learning of the reading and writing, involving the whole educational community

    Euclid preparation: XVI. Exploring the ultra-low surface brightness Universe with Euclid /VIS

    Get PDF
    Context. While Euclid is an ESA mission specifically designed to investigate the nature of dark energy and dark matter, the planned unprecedented combination of survey area (∼15â 000 deg2), spatial resolution, low sky-background, and depth also make Euclid an excellent space observatory for the study of the low surface brightness Universe. Scientific exploitation of the extended low surface brightness structures requires dedicated calibration procedures that are yet to be tested. Aims. We investigate the capabilities of Euclid to detect extended low surface brightness structure by identifying and quantifying sky-background sources and stray-light contamination. We test the feasibility of generating sky flat-fields to reduce large-scale residual gradients in order to reveal the extended emission of galaxies observed in the Euclid survey. Methods. We simulated a realistic set of Euclid/VIS observations, taking into account both instrumental and astronomical sources of contamination, including cosmic rays, stray-light, zodiacal light, interstellar medium, and the cosmic infrared background, while simulating the effects of background sources in the field of view. Results. We demonstrate that a combination of calibration lamps, sky flats, and self-calibration would enable recovery of emission at a limiting surface brightness magnitude of μlim = 29.5-0.27+0.08 mag arcsec-2 (3σ, 10â ×â 10 arcsec2) in the Wide Survey, and it would reach regions deeper by 2 mag in the Deep Surveys. Conclusions.Euclid/VIS has the potential to be an excellent low surface brightness observatory. Covering the gap between pixel-To-pixel calibration lamp flats and self-calibration observations for large scales, the application of sky flat-fielding will enhance the sensitivity of the VIS detector at scales larger than 1″, up to the size of the field of view, enabling Euclid to detect extended surface brightness structures below μlimâ =â 31 mag arcsec-2 and beyond

    Euclid preparation. XXIX. Water ice in spacecraft part I: The physics of ice formation and contamination

    Get PDF
    Molecular contamination is a well-known problem in space flight. Water is the most common contaminant and alters numerous properties of a cryogenic optical system. Too much ice means that Euclid's calibration requirements and science goals cannot be met. Euclid must then be thermally decontaminated, a long and risky process. We need to understand how iced optics affect the data and when a decontamination is required. This is essential to build adequate calibration and survey plans, yet a comprehensive analysis in the context of an astrophysical space survey has not been done before. In this paper we look at other spacecraft with well-documented outgassing records, and we review the formation of thin ice films. A mix of amorphous and crystalline ices is expected for Euclid. Their surface topography depends on the competing energetic needs of the substrate-water and the water-water interfaces, and is hard to predict with current theories. We illustrate that with scanning-tunnelling and atomic-force microscope images. Industrial tools exist to estimate contamination, and we must understand their uncertainties. We find considerable knowledge errors on the diffusion and sublimation coefficients, limiting the accuracy of these tools. We developed a water transport model to compute contamination rates in Euclid, and find general agreement with industry estimates. Tests of the Euclid flight hardware in space simulators did not pick up contamination signals; our in-flight calibrations observations will be much more sensitive. We must understand the link between the amount of ice on the optics and its effect on Euclid's data. Little research is available about this link, possibly because other spacecraft can decontaminate easily, quenching the need for a deeper understanding. In our second paper we quantify the various effects of iced optics on spectrophotometric data.Comment: 35 pages, 22 figures, A&A in press. Changes to previous version: language edits, added Z. Bolag as author in the arxiv PDF (was listed in the ASCII author list and in the journal PDF, but not in the arxiv PDF). This version is identical to the journal versio

    Euclid preparation. XVIII. The NISP photometric system

    Full text link
    Euclid will be the first space mission to survey most of the extragalactic sky in the 0.95-2.02 μ\mum range, to a 5σ\sigma point-source median depth of 24.4 AB mag. This unique photometric data set will find wide use beyond Euclid's core science. In this paper, we present accurate computations of the Euclid Y_E, J_E and H_E passbands used by the Near-Infrared Spectrometer and Photometer (NISP), and the associated photometric system. We pay particular attention to passband variations in the field of view, accounting among others for spatially variable filter transmission, and variations of the angle of incidence on the filter substrate using optical ray tracing. The response curves' cut-on and cut-off wavelengths - and their variation in the field of view - are determined with 0.8 nm accuracy, essential for the photometric redshift accuracy required by Euclid. After computing the photometric zeropoints in the AB mag system, we present linear transformations from and to common ground-based near-infrared photometric systems, for normal stars, red and brown dwarfs, and galaxies separately. A Python tool to compute accurate magnitudes for arbitrary passbands and spectral energy distributions is provided. We discuss various factors from space weathering to material outgassing that may slowly alter Euclid's spectral response. At the absolute flux scale, the Euclid in-flight calibration program connects the NISP photometric system to Hubble Space Telescope spectrophotometric white dwarf standards; at the relative flux scale, the chromatic evolution of the response is tracked at the milli-mag level. In this way, we establish an accurate photometric system that is fully controlled throughout Euclid's lifetime.Comment: 33 pages, 25 figures, accepted for publication in A&

    Euclid preparation XVIII. The NISP photometric system

    Get PDF
    Euclid will be the first space mission to survey most of the extragalactic sky in the 0.95–2.02 µm range, to a 5 σ point-source median depth of 24.4 AB mag. This unique photometric dataset will find wide use beyond Euclid’s core science. In this paper, we present accurate computations of the Euclid YE, JE, and HE passbands used by the Near-Infrared Spectrometer and Photometer (NISP), and the associated photometric system. We pay particular attention to passband variations in the field of view, accounting for, among other factors, spatially variable filter transmission and variations in the angle of incidence on the filter substrate using optical ray tracing. The response curves’ cut-on and cut-off wavelengths – and their variation in the field of view – are determined with ∼0.8 nm accuracy, essential for the photometric redshift accuracy required by Euclid. After computing the photometric zero points in the AB mag system, we present linear transformations from and to common ground-based near-infrared photometric systems, for normal stars, red and brown dwarfs, and galaxies separately. A Python tool to compute accurate magnitudes for arbitrary passbands and spectral energy distributions is provided. We discuss various factors, from space weathering to material outgassing, that may slowly alter Euclid’s spectral response. At the absolute flux scale, the Euclid in-flight calibration program connects the NISP photometric system to Hubble Space Telescope spectrophotometric white dwarf standards; at the relative flux scale, the chromatic evolution of the response is tracked at the milli-mag level. In this way, we establish an accurate photometric system that is fully controlled throughout Euclid’s lifetime

    Euclid preparation: I. the Euclid Wide Survey

    Get PDF
    Euclid is a mission of the European Space Agency that is designed to constrain the properties of dark energy and gravity via weak gravitational lensing and galaxy clustering. It will carry out a wide area imaging and spectroscopy survey (the Euclid Wide Survey: EWS) in visible and near-infrared bands, covering approximately 15 000 deg2 of extragalactic sky in six years. The wide-field telescope and instruments are optimised for pristine point spread function and reduced stray light, producing very crisp images. This paper presents the building of the Euclid reference survey: The sequence of pointings of EWS, deep fields, and calibration fields, as well as spacecraft movements followed by Euclid as it operates in a step-And-stare mode from its orbit around the Lagrange point L2. Each EWS pointing has four dithered frames; we simulated the dither pattern at the pixel level to analyse the effective coverage. We used up-To-date models for the sky background to define the Euclid region-of-interest (RoI). The building of the reference survey is highly constrained from calibration cadences, spacecraft constraints, and background levels; synergies with ground-based coverage were also considered. Via purposely built software, we first generated a schedule for the calibrations and deep fields observations. On a second stage, the RoI was tiled and scheduled with EWS observations, using an algorithm optimised to prioritise the best sky areas, produce a compact coverage, and ensure thermal stability. The result is the optimised reference survey RSD-2021A, which fulfils all constraints and is a good proxy for the final solution. The current EWS covers ∼14.500 deg2. The limiting AB magnitudes (5ρpoint-like source) achieved in its footprint are estimated to be 26.2 (visible band IE) and 24.5 (for near infrared bands YE, JE, HE); for spectroscopy, the Hα line flux limit is 2.10-16 erg-1 cm-2 s-1 at 1600 nm; and for diffuse emission, the surface brightness limits are 29.8 (visible band) and 28.4 (near infrared bands) mag arcsec-2

    Euclid preparation: XVI. Exploring the ultra-low surface brightness Universe with Euclid/VIS

    Get PDF
    Context While Euclid is an ESA mission specifically designed to investigate the nature of dark energy and dark matter, the planned unprecedented combination of survey area (∼15 000 deg2), spatial resolution, low sky-background, and depth also make Euclid an excellent space observatory for the study of the low surface brightness Universe. Scientific exploitation of the extended low surface brightness structures requires dedicated calibration procedures that are yet to be tested. Aims We investigate the capabilities of Euclid to detect extended low surface brightness structure by identifying and quantifying sky-background sources and stray-light contamination. We test the feasibility of generating sky flat-fields to reduce large-scale residual gradients in order to reveal the extended emission of galaxies observed in the Euclid survey. Methods We simulated a realistic set of Euclid/VIS observations, taking into account both instrumental and astronomical sources of contamination, including cosmic rays, stray-light, zodiacal light, interstellar medium, and the cosmic infrared background, while simulating the effects of background sources in the field of view. Results We demonstrate that a combination of calibration lamps, sky flats, and self-calibration would enable recovery of emission at a limiting surface brightness magnitude of μlim = 29.5-0.2+0.08 mag arcsec-2 (3σ, 10 × 10 arcsec2) in the Wide Survey, and it would reach regions deeper by 2 mag in the Deep Surveys. Conclusions Euclid/VIS has the potential to be an excellent low surface brightness observatory. Covering the gap between pixel-To-pixel calibration lamp flats and self-calibration observations for large scales, the application of sky flat-fielding will enhance the sensitivity of the VIS detector at scales larger than 1″, up to the size of the field of view, enabling Euclid to detect extended surface brightness structures below μlim = 31 mag arcsec-2 and beyond

    Euclid preparation: XVIII. The NISP photometric system

    Get PDF
    Galaxie

    Una fiesta poética [Texto impreso] : los valencianos en la Argentina

    No full text
    Contenido parcial : Las violetas / Venancio Serrano Claver
    corecore