5 research outputs found

    J-PLUS: The javalambre photometric local universe survey

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    ABSTRACT: TheJavalambrePhotometric Local UniverseSurvey (J-PLUS )isanongoing 12-band photometricopticalsurvey, observingthousands of squaredegrees of theNorthernHemispherefromthededicated JAST/T80 telescope at the Observatorio Astrofísico de Javalambre (OAJ). The T80Cam is a camera with a field of view of 2 deg2 mountedon a telescopewith a diameter of 83 cm, and isequippedwith a uniquesystem of filtersspanningtheentireopticalrange (3500–10 000 Å). Thisfiltersystemis a combination of broad-, medium-, and narrow-band filters, optimallydesigned to extracttherest-framespectralfeatures (the 3700–4000 Å Balmer break region, Hδ, Ca H+K, the G band, and the Mg b and Ca triplets) that are key to characterizingstellartypes and delivering a low-resolutionphotospectrumforeach pixel of theobservedsky. With a typicaldepth of AB ∼21.25 mag per band, thisfilter set thusallowsforanunbiased and accuratecharacterization of thestellarpopulation in our Galaxy, itprovidesanunprecedented 2D photospectralinformationforall resolved galaxies in the local Universe, as well as accuratephoto-z estimates (at the δ z/(1 + z)∼0.005–0.03 precisionlevel) formoderatelybright (up to r ∼ 20 mag) extragalacticsources. Whilesomenarrow-band filters are designedforthestudy of particular emissionfeatures ([O II]/λ3727, Hα/λ6563) up to z < 0.017, theyalsoprovidewell-definedwindowsfortheanalysis of otheremissionlines at higherredshifts. As a result, J-PLUS has thepotential to contribute to a widerange of fields in Astrophysics, both in thenearbyUniverse (MilkyWaystructure, globular clusters, 2D IFU-likestudies, stellarpopulations of nearby and moderate-redshiftgalaxies, clusters of galaxies) and at highredshifts (emission-line galaxies at z ≈ 0.77, 2.2, and 4.4, quasi-stellarobjects, etc.). Withthispaper, wereleasethefirst∼1000 deg2 of J-PLUS data, containingabout 4.3 millionstars and 3.0 milliongalaxies at r <  21mag. With a goal of 8500 deg2 forthe total J-PLUS footprint, thesenumbers are expected to rise to about 35 millionstars and 24 milliongalaxiesbytheend of thesurvey.Funding for the J-PLUS Project has been provided by the Governments of Spain and Aragón through the Fondo de Inversiones de Teruel, the Spanish Ministry of Economy and Competitiveness (MINECO; under grants AYA2017-86274-P, AYA2016-77846-P, AYA2016-77237-C3-1-P, AYA2015-66211-C2-1-P, AYA2015-66211-C2-2, AYA2012-30789, AGAUR grant SGR-661/2017, and ICTS-2009-14), and European FEDER funding (FCDD10-4E-867, FCDD13-4E-2685

    Caracterização hidráulica do microaspersor Rondo, da Plastro Hydraulic characterization of the Plastro Rondo microsprinkler

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    Com o objetivo de se determinar as características hidráulicas do microaspersor Rondo 50 L h-1, de bocal azul, fabricado pela Plastro, conduziram-se testes no Laboratório de Hidráulica da Escola Superior de Agricultura de Mossoró, determinando-se a equação característica vazão - pressão, o coeficiente de variação de fabricação (CVf), o perfil de distribuição, o diagrama pluviométrico e a uniformidade de distribuição de água pelo microaspersor. A equação característica obtida foi q = 3,4312H0,516, caracterizando fluxo turbulento; o CVf médio foi considerado excelente e o microaspersor apresentou um raio de alcance igual a 3,3 m. O espaçamento com melhor uniformidade de distribuição e superposição, foi o de 1,2 x 1,2 m, embora para espaçamentos de até 3,6 x 3,6 m, a uniformidade de distribuição tenha sido superior a 80%.<br>In order to assess the hydraulic characteristics of the microsprinkler Rondo 50 L h-1, with blue nozzle, manufactured by Plastro, tests were carried out in the Hydraulic Laboratory of the Escola Superior de Agricultura de Mossoró (ESAM). Estimates were made for discharge pressure head equation, manufacturer’s coefficient of variation, profile of distribution, uniformity of water application and water application uniformity with overlap. The manufacture’s coefficient of variation is classified as excellent and the characteristic equation is q = 3.4312 H0.516, characterizing a turbulent flow. The microsplinker has a throw radius of a 3.3 m. The best emitter spacing with overlap found was 1.2 x 1.2 m, although for spacing up to 3.6 x 3.6 m the application uniformity was above 80%
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