129 research outputs found

    Parasitosis en el proventrículo por Procyrnea sp. (Spiruroidea: Habronematidae), de un aguililla caminera (Rupornis magnirostris) del estado de Veracruz, México: reporte de un caso

    Get PDF
    The report presented herein describes the necropsy findings (red nodules over the linning of the proventriculus) in an adult female roadside hawk (Rupornis magnirostris) found in Veracruz State, Mexico. We further provide the description of a nematode from the genus Procyrnea found in the proventriculus wall including histopathological sections of tissue damage associated with the parasite.The report presented herein describes the necropsy findings (red nodules over the linning of the proventriculus) in an adult female roadside hawk (Rupornis magnirostris) found in Veracruz State, Mexico. We further provide the description of a nematode from the genus Procyrnea found in the proventriculus wall including histopathological sections of tissue damage associated with the parasite

    Nuevas arquitecturas hardware de procesamiento de alto rendimiento para aprendizaje profundo

    Get PDF
    El diseño y fabricación de hardware es costoso, tanto en tiempo como en inversión económica, razón por la que los circuitos integrados se fabrican siempre en gran volumen, para aprovechar la economía de escala. Por esa razón la mayoría de procesadores fabricados son de propósito general, ampliando así su campo de aplicaciones. En los últimos años, sin embargo, cada vez se fabrican más procesadores para aplicaciones específicas, entre ellos aquellos destinados a acelerar el trabajo con redes neuronales profundas. Este artículo introduce la necesidad de este tipo de hardware especializado, describiendo su finalidad, funcionamiento e implementaciones actuales.The design and manufacture of hardware is expensive, both in time and in economic investment, which is why integrated circuits are always manufactured in large volume, to take advantage of economies of scale. For this reason, the majority of processors manufactured are general purpose, thus expanding its range of applications. In recent years, however, more and more processors are being manufactured for specific applications, including those aimed at accelerating work with deep neural networks. This article introduces the need for this type of specialized hardware, describing its purpose, operation and current implementations.Universidad de Granada: Departamento de Arquitectura y Tecnología de Computadore

    Stellar spectral-type (mass) dependence of the dearth of close-in planets around fast-rotating stars. Architecture of Kepler confirmed single-exoplanet systems compared to star-planet evolution models

    Full text link
    In 2013 a dearth of close-in planets around fast-rotating host stars was found using statistical tests on Kepler data. The addition of more Kepler and Transiting Exoplanet Survey Satellite (TESS) systems in 2022 filled this region of the diagram of stellar rotation period (Prot) versus the planet orbital period (Porb). We revisited the Prot extraction of Kepler planet-host stars, we classify the stars by their spectral type, and we studied their Prot-Porb relations. We only used confirmed exoplanet systems to minimize biases. In order to learn about the physical processes at work, we used the star-planet evolution code ESPEM (French acronym for Evolution of Planetary Systems and Magnetism) to compute a realistic population synthesis of exoplanet systems and compared them with observations. Because ESPEM works with a single planet orbiting around a single main-sequence star, we limit our study to this population of Kepler observed systems filtering out binaries, evolved stars, and multi-planets. We find in both, observations and simulations, the existence of a dearth in close-in planets orbiting around fast-rotating stars, with a dependence on the stellar spectral type (F, G, and K), which is a proxy of the mass in our sample of stars. There is a change in the edge of the dearth as a function of the spectral type (and mass). It moves towards shorter Prot as temperature (and mass) increases, making the dearth look smaller. Realistic formation hypotheses included in the model and the proper treatment of tidal and magnetic migration are enough to qualitatively explain the dearth of hot planets around fast-rotating stars and the uncovered trend with spectral type.Comment: Accepted in A&A. 13 pages, 8 figure

    ASASSN-15oi: A Rapidly Evolving, Luminous Tidal Disruption Event at 216 Mpc

    Get PDF
    We present ground-based and Swift photometric and spectroscopic observations of the tidal disruption event (TDE) ASASSN-15oi, discovered at the center of 2MASX J20390918-3045201 (d216d\simeq216 Mpc) by the All-Sky Automated Survey for SuperNovae (ASAS-SN). The source peaked at a bolometric luminosity of L1.9×1044L\simeq1.9\times10^{44} ergs s1^{-1} and radiated a total energy of E5.0×1050E\simeq5.0\times10^{50} ergs over the 3.5\sim3.5 months of observations. The early optical/UV emission of the source can be fit by a blackbody with temperature increasing from T2×104T\sim2\times10^4 K to T6×104T\sim6\times10^4 K while the luminosity declines from L1.9×1044L\simeq1.9\times10^{44} ergs s1^{-1} to L2.8×1043L\simeq2.8\times10^{43} ergs s1^{-1}, requiring the photosphere to be shrinking rapidly. The optical/UV luminosity decline is broadly consistent with an exponential decline, Let/t0L\propto e^{-t/t_0}, with t035t_0\simeq35 days. ASASSN-15oi also exhibits roughly constant soft X-ray emission that is significantly weaker than the optical/UV emission. Spectra of the source show broad helium emission lines and strong blue continuum emission in early epochs, although these features fade rapidly and are not present 3\sim3 months after discovery. The early spectroscopic features and color evolution of ASASSN-15oi are consistent with a TDE, but the rapid spectral evolution is unique among optically-selected TDEs

    Red-giant and main-sequence solar-like oscillators in binary systems revealed by ESA Gaia Data Release 3 -- Reconstructing stellar and orbital evolution from binary-star ensemble seismology

    Full text link
    Binary systems constitute a valuable astrophysics tool for testing our understanding of stellar structure and evolution. Systems containing a oscillating component are interesting as asteroseismology offers independent parameters for the oscillating component that aid the analysis. About 150 of such systems are known in the literature. To enlarge the sample of these benchmark objects, we crossmatch the Two-Body-Orbit Catalogue (TBO) of Gaia DR3, with catalogs of confirmed solar-like oscillators on the main-sequence and red-giant phase from NASA Kepler and TESS. We obtain 954 new binary system candidates hosting solar-like oscillators, of which 45 and 909 stars are on the main sequence and red-giant, resp., including 2 new red giants in eclipsing systems. 918 oscillators in potentially long-periodic systems are reported. We increase the sample size of known solar-like oscillators in binary systems by an order of magnitude. We present the seismic properties of the full sample and conclude that the grand majority of the orbital elements in the TBO is physically reasonable. 82% of all TBO binary candidates with multiple times with APOGEE are confirmed from radial-velocity measurement. However, we suggest that due to instrumental noise of the TESS satellite the seismically inferred masses and radii of stars with νmax\nu_\textrm{max}\lesssim30μ\muHz could be significantly overestimated. For 146 giants the seismically inferred evolutionary state has been determined and shows clear differences in their distribution in the orbital parameters, which are accounted the accumulative effect of the equilibrium tide acting in these evolved binary systems. For other 146 systems hosting oscillating stars values for the orbital inclination were found in the TBO. From testing the TBO on the SB9 catalogue, we obtain a completeness factor of 1/3.Comment: under review for publication in A&A (22 pages + 4 pages of appendix, 21 figures, 33 pages of tables in the Appendix

    The ASAS-SN bright supernova catalogue - III. 2016

    Get PDF
    This catalogue summarizes information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) and all other bright (mpeak ≤ 17), spectroscopically confirmed supernovae discovered in 2016. We then gather the near-infrared through ultraviolet magnitudes of all host galaxies and the offsets of the supernovae from the centres of their hosts from public data bases. We illustrate the results using a sample that now totals 668 supernovae discovered since 2014 May 1, including the supernovae from our previous catalogues, with type distributions closely matching those of the ideal magnitude limited sample from Li et al. This is the third of a series of yearly papers on bright supernovae and their hosts from the ASAS-SN team

    The ASAS-SN Bright Supernova Catalog - II. 2015

    Get PDF
    This manuscript presents information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) during 2015, its second full year of operations. The same information is presented for bright (mV17m_V\leq17), spectroscopically confirmed supernovae discovered by other sources in 2015. As with the first ASAS-SN bright supernova catalog, we also present redshifts and near-UV through IR magnitudes for all supernova host galaxies in both samples. Combined with our previous catalog, this work comprises a complete catalog of 455 supernovae from multiple professional and amateur sources, allowing for population studies that were previously impossible. This is the second of a series of yearly papers on bright supernovae and their hosts from the ASAS-SN team
    corecore