75 research outputs found

    Comportamiento agronómico, rendimiento productivo y calidad industrial de trece genotipos y una variedad comercial de arroz (Oryza sativa L.) bajo condiciones de riego en el Valle de Sébaco, Matagalpa, II Semestre 2016

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    Durante el II semestre del año 2016, se realizó la presente investigación con el objetivo de evaluar el comportamiento agronómico, rendimiento productivo y calidad industrial de trece genotipos y una variedad comercial de arroz (Oryza sativa L.) bajo condiciones de riego. El experimento se estableció en el Centro Experimental TAINIC en la comarca El Horno, municipio de Ciudad Darío, Matagalpa, siendo sus coordenadas geográficas de 12°48´51" de latitud Norte, y 86°09´53" de longitud Oeste con una altitud de 460 msnm. El diseño utilizado para evaluar los genotipos de arroz fue el de Bloques Completos al Azar con un total de un total de 14 tratamientos y 4 repeticiones. Utilizándose ANDEVA y separación de media por Tukey (∞=0.05) para determinar significancia. Los principales resultados indican que los tratamientos 7, 3 y 2 (CT18504-4-5-3Vi-2-3P, IR31917-45-3-2-1-1SR-5-M y IR77430-14-B-1-2-B-3-4SR-1-M) obtuvieron el mayor rendimiento de grano con 7582.4, 7434.5 y 7127.1 kilogramos por hectárea respectivamente. Los componentes como la habilidad de macollamiento y el número de granos por panícula fueron determinantes para obtener mayor rendimiento en los genotipos. Se destaca el hecho que según la escala CIAT 10 de los genotipos se clasifican como Semienanos y 4 de los genotipos se clasifican en la categoría intermedia. Los tratamientos acriollados 11, 12, 13 y el tratamiento testigo 14 (Tres Mesino Rojo, Enano, Fortuna e INTA L-9) obtuvieron la mejor relación entero/quebrado con 95/05, 93/07, 93/07 y 92/08 respectivamente. Palabras claves: genotipos, rendimiento de grano, macollamiento, granos por panícul

    Identifying the SN 2022acko progenitor with JWST

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    We report on analysis using the James Webb Space Telescope (JWST) to identify a candidate progenitor star of the Type II-plateau supernova SN 2022acko in the nearby, barred spiral galaxy NGC 1300. To our knowledge, our discovery represents the first time JWST has been used to localize a progenitor system in pre-explosion archival Hubble Space Telescope (HST) images. We astrometrically registered a JWST NIRCam image from 2023 January, in which the SN was serendipitously captured, to pre-SN HST F160W and F814W images from 2017 and 2004, respectively. An object corresponding precisely to the SN position has been isolated with reasonable confidence. That object has a spectral energy distribution (SED) and overall luminosity consistent with a single-star model having an initial mass possibly somewhat less than the canonical 8 Msun theoretical threshold for core collapse (although masses as high as 9 Msun for the star are also possible); however, the star's SED and luminosity are inconsistent with that of a super-asymptotic giant branch star which might be a forerunner of an electron-capture SN. The properties of the progenitor alone imply that SN 2022acko is a relatively normal SN II-P, albeit most likely a low-luminosity one. The progenitor candidate should be confirmed with follow-up HST imaging at late times, when the SN has sufficiently faded. This potential use of JWST opens a new era of identifying SN progenitor candidates at high spatial resolution.Comment: 8 pages, substantial changes from v1, to appear in MNRA

    SN 2022jox: An extraordinarily ordinary Type II SN with Flash Spectroscopy

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    We present high cadence optical and ultraviolet observations of the Type II supernova (SN), SN 2022jox which exhibits early spectroscopic high ionization flash features of \ion{H}{1}, \ion{He}{2}, \ion{C}{4}, and \ion{N}{4} that disappear within the first few days after explosion. SN 2022jox was discovered by the Distance Less than 40 Mpc (DLT40) survey \sim0.75 days after explosion with followup spectra and UV photometry obtained within minutes of discovery. The SN reached a peak brightness of MV_V \sim -17.3 mag, and has an estimated 56^{56}Ni mass of 0.04 M_{\odot}, typical values for normal Type II SNe. The modeling of the early lightcurve and the strong flash signatures present in the optical spectra indicate interaction with circumstellar material (CSM) created from a progenitor with a mass loss rate of M˙103102 M yr1\dot{M} \sim 10^{-3}-10^{-2}\ M_\odot\ \mathrm{yr}^{-1}. There may also be some indication of late-time CSM interaction in the form of an emission line blueward of Hα\alpha seen in spectra around 200 days. The mass-loss rate is much higher than the values typically associated with quiescent mass loss from red supergiants, the known progenitors of Type II SNe, but is comparable to inferred values from similar core collapse SNe with flash features, suggesting an eruptive event or a superwind in the progenitor in the months or years before explosion.Comment: Submitted to Ap

    Circumstellar Medium Interaction in SN 2018lab, A Low-Luminosity II-P Supernova observed with TESS

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    We present photometric and spectroscopic data of SN 2018lab, a low luminosity type IIP supernova (LLSN) with a V-band peak luminosity of 15.1±0.1-15.1\pm0.1 mag. SN 2018lab was discovered by the Distance Less Than 40 Mpc (DLT40) SNe survey only 0.73 days post-explosion, as determined by observations from the Transiting Exoplanet Survey Satellite (TESS). TESS observations of SN 2018lab yield a densely sampled, fast-rising, early time light curve likely powered by circumstellar medium (CSM) interaction. The blue-shifted, broadened flash feature in the earliest spectra (<<2 days) of SN 2018lab provide further evidence for ejecta-CSM interaction. The early emission features in the spectra of SN 2018lab are well described by models of a red supergiant progenitor with an extended envelope and close-in CSM. As one of the few LLSNe with observed flash features, SN 2018lab highlights the need for more early spectra to explain the diversity of flash feature morphology in type II SNe

    Shock Cooling and Possible Precursor Emission in the Early Light Curve of the Type II SN 2023ixf

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    We present the densely sampled early light curve of the Type II supernova (SN) 2023ixf, first observed within hours of explosion in the nearby Pinwheel Galaxy (Messier 101; 6.7 Mpc). Comparing these data to recently updated models of shock cooling emission, we find that the progenitor likely had a radius of 410±10 R410 \pm 10\ R_\odot (statistical uncertainty only), consistent with a red supergiant. These models provide a good fit to the data starting about 1 day after the explosion, despite the fact that the classification spectrum shows signatures of circumstellar material around SN 2023ixf during that time. Photometry during the first day after the explosion, provided almost entirely by amateur astronomers, does not agree with the shock cooling models or a simple power-law rise fit to data after 1 day. We consider the possible causes of this discrepancy, including precursor activity from the progenitor star, circumstellar interaction, and emission from the shock before or after it breaks out of the stellar surface. The very low luminosity (11 mag>M>14 mag-11\mathrm{\ mag} > M > -14\mathrm{\ mag}) and short duration of the initial excess leads us to prefer a scenario related to prolonged emission from the SN shock traveling through the progenitor system.Comment: submitted to ApJ

    The Rural Household Multiple Indicator Survey, data from 13,310 farm households in 21 countries

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    The Rural Household Multiple Indicator Survey (RHoMIS) is a standardized farm household survey approach which collects information on 758 variables covering household demographics, farm area, crops grown and their production, livestock holdings and their production, agricultural product use and variables underlying standard socio-economic and food security indicators such as the Probability of Poverty Index, the Household Food Insecurity Access Scale, and household dietary diversity. These variables are used to quantify more than 40 different indicators on farm and household characteristics, welfare, productivity, and economic performance. Between 2015 and the beginning of 2018, the survey instrument was applied in 21 countries in Central America, sub-Saharan Africa and Asia. The data presented here include the raw survey response data, the indicator calculation code, and the resulting indicator values. These data can be used to quantify on- and off-farm pathways to food security, diverse diets, and changes in poverty for rural smallholder farm households

    Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

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    A measurement of the cosmic-ray spectrum for energies exceeding 4×10184{\times}10^{18} eV is presented, which is based on the analysis of showers with zenith angles greater than 6060^{\circ} detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×10185.3{\times}10^{18} eV, the "ankle", the flux can be described by a power law EγE^{-\gamma} with index γ=2.70±0.02(stat)±0.1(sys)\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)} followed by a smooth suppression region. For the energy (EsE_\text{s}) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25(stat)1.2+1.0(sys))×1019E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19} eV.Comment: Replaced with published version. Added journal reference and DO

    Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

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    The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
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