3,532 research outputs found

    Microlensing events in the Galactic bulge

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    For the first time we detected microlensing events at zero latitude in the Galactic bulge using the VISTA Variables in the Via Lactea Survey (VVV) data. We have discovered a total sample of N = 630 events within an area covering 20.7 sq. deg. Using the near-IR color magnitude diagram we selected N = 291 red clump sources, allowing us to analyse the longitude dependence of microlensing across the central region of the Galactic plane. We thoroughly accounted for the photometric and sampling efficiency. The spatial distribution is homogeneous, with the number of events smoothly increasing toward the Galactic center. We find a slight asymmetry, with a larger number of events toward negative longitudes than positive longitudes, that is possibly related with the inclination of the bar along the line of sight. We also examined the timescale distribution which shows a mean on 17.4 +- 1.0 days for the whole sample, and 20.7 +- 1.0 for the Red Clump subsample.Comment: Proceedings of the Fifteenth Marcel Grossman Meeting on General Relativity Edited by Elia Battistelli, Robert T. Jantzen, and Remo Ruffini. 6 pages, 3 figures, to be published in Open access e-book proceedings World Scientific, Singapore, 201

    Actitudes del personal hacia la inclusión laboral de personas con discapacidad según factores sociodemográficos en las oficinas de las empresas del sector servicio de Lima Metropolitana

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    Compara las actitudes del personal hacia la inclusión laboral de personas con discapacidad según factores sociodemográficos en las oficinas de las empresas del sector servicio de Lima Metropolitana en el 2018, tomando una muestra de 235 trabajadores. El diseño de la investigación es no experimental, descriptiva comparativa de corte transversal, se administró el instrumento de Verdugo y al (1997) la Escala de Actitudes hacia las Personas con Discapacidad, asimismo, los factores sociodemográficos empleados y los resultados obtenidos fueron : según el sexo, hombres y mujeres se muestran abiertos a la inclusión laboral; según la edad, personas cuyas edades están entre 18 y 30, muestras mayor apertura a la inclusión a comparación de las personas mayores de 30; según la función del personal, los profesionales muestran mayor apertura a la inclusión a comparación de sus pares; según la condición laboral, ambos colaboradores muestran apertura a la inclusión; según la frecuencia del contacto, quienes tienen contacto frecuente y muy frecuente muestran mayor apertura a la inclusión a comparación de quienes tienen poco contacto o casi nulo; finalmente, según el tipo de discapacidad, las personas muestran mayor apertura a quienes presenten discapacidad múltiple, a comparación de quienes presenten una discapacidad.Tesi

    Eclipsing binary stars in the era of massive surveys: First results and future prospects

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    Our thinking about eclipsing binary stars has undergone a tremendous change in the last decade. Eclipsing binary stars are one of nature’s best laboratories for determining the fundamental physical properties of stars and thus for testing the predictions of theoretical models. Some of the largest ongoing variable star surveys include the Catalina Real-time Transient Survey (CRTS) and the VISTA Variables in the Vía Láctea survey (VVV). They both contain a large amount of photometric data and plenty of information about eclipsing binaries that wait to be extracted and exploited. Here we briefly describe our efforts in this direction

    THROES: a caTalogue of HeRschel Observations of Evolved Stars. I. PACS range spectroscopy

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    This is the first of a series of papers presenting the THROES (A caTalogue of HeRschel Observations of Evolved Stars) project, intended to provide a comprehensive overview of the spectroscopic results obtained in the far-infrared (55-670 microns) with the Her- schel space observatory on low-to-intermediate mass evolved stars in our Galaxy. Here we introduce the catalogue of interactively reprocessed PACS (Photoconductor Array Camera and Spectrometer) spectra covering the 55-200 microns range for 114 stars in this category for which PACS range spectroscopic data is available in the Herschel Science Archive (HSA). Our sample includes objects spanning a range of evolutionary stages, from the asymptotic giant branch to the planetary nebula phase, displaying a wide variety of chemical and physical properties. The THROES/PACS catalogue is accessible via a dedicated web-based inter- face (https://throes.cab.inta-csic.es/) and includes not only the science-ready Herschel spectroscopic data for each source, but also complementary photometric and spectroscopic data from other infrared observatories, namely IRAS (Infrared Astronomical Satellite), ISO (Infrared Space Observatory) or AKARI, at overlapping wavelengths. Our goal is to create a legacy-value Herschel dataset that can be used by the scientific community in the future to deepen our knowledge and understanding of these latest stages of the evolution of low-to-intermediate mass stars.Comment: 38 page

    The asymptotic evolution of the stellar merger V1309 Sco: a Blue Straggler in the making?

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    © 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.Stellar mergers are estimated to be common events in the Galaxy. The best studied stellar merger case to date is V1309 Sco (= Nova Scorpii 2008) which was originally misclassified as a Nova event. Later identified as the merger of the components of a cool overcontact binary system with 1.52 M and 0.16 M, V1309 Sco showed an initial period of P = 1.4 d before the merger. Post-outburst evolution demonstrated that V1309 Sco was unlike the typical Classical Novae and Symbiotic Recurrent Novae with significant dust production around it, and indicated that the system may become a post-AGB (or pre-PN) soon. Here we present a study of V1309 Sco about 10 yr after the outburst, based on near-IR variability and colour data from the ESO surveys VISTA Variables in the Vía Láctea (VVV) and VVV eXtended (VVVX). We find that reasonable equilibrium in this stellar merger is being reached and that the star has settled into a nearly constant magnitude. A dramatic change in its near-IR colours from (J - K s) = 1.40 in 2010 to (J - K S) = 0.42 in 2015 and a possible low-amplitude periodic signal with P = 0.49 d in the post-outburst data are consistent with a 'blue straggler' star, predicted to be formed from a stellar merger.Peer reviewe
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