9 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

    The multichord stellar occultation by the centaur Bienor on January 11, 2019

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    Within our program of physical characterization of trans-Neptunian objects and centaurs, we predicted a stellar occultation by the centaur (54598) Bienor to occur on January 11, 2019, with good observability potential. We obtained high accuracy astrometric data to refine the prediction, resulting in a shadow path favorable for the Iberian Peninsula. This encouraged us to carry out an occultation observation campaign that resulted in five positive detections from four observing sites. This is the fourth centaur for which a multichord (more than two chords) stellar occultation has been observed so far, the other three being (2060) Chiron, (10199) Chariklo, and (95626) 2002 GZ32. From the analysis of the occultation chords, combined with the rotational light curve obtained shortly after the occultation, we determined that Bienor has an area-equivalent diameter of 150 +/- 20 km. This diameter is ~ 30 km smaller than the one obtained from thermal measurements. The position angle of the short axis of the best fitting ellipse obtained through the analysis of the stellar occultation does not match that of the spin axis derived from long-term photometric models. We also detected a strong irregularity in one of the minima of the rotational light curve that is present no matter the aspect angle at which the observations were done.We present different scenarios to reconcile the results from the different techniques.We did not detect secondary dropsrelated to potential rings or satellites. Nonetheless, similar rings in size to that of Chariklo’s cannot be discarded due to low data accuracy

    The 2017 May 20 stellar occultation by the elongated centaur (95626) 2002 GZ32

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    We predicted a stellar occultation of the bright star Gaia DR1 4332852996360346368 (UCAC4 385-75921) (mV = 14.0 mag) by the centaur 2002 GZ32 for 2017 May 20. Our latest shadow path prediction was favourable to a large region in Europe. Observations were arranged in a broad region inside the nominal shadow path. Series of images were obtained with 29 telescopes throughout Europe and from six of them (five in Spain and one in Greece) we detected the occultation. This is the fourth centaur, besides Chariklo, Chiron, and Bienor, for which a multichord stellar occultation is reported. By means of an elliptical fit to the occultation chords, we obtained the limb of 2002 GZ32 during the occultation, resulting in an ellipse with axes of 305 ± 17 km × 146 ± 8 km. From this limb, thanks to a rotational light curve obtained shortly after the occultation, we derived the geometric albedo of 2002 GZ32 (pV = 0.043 ± 0.007) and a 3D ellipsoidal shape with axes 366 km × 306 km × 120 km. This shape is not fully consistent with a homogeneous body in hydrostatic equilibrium for the known rotation period of 2002 GZ32. The size (albedo) obtained from the occultation is respectively smaller (greater) than that derived from the radiometric technique but compatible within error bars. No rings or debris around 2002 GZ32 were detected from the occultation, but narrow and thin rings cannot be discarded. © 2021 2020 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society

    The miniJPAS survey: a preview of the Universe in 56 colours

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    International audienceThe Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will soon start to scan thousands of square degrees of the northern extragalactic sky with a unique set of 5656 optical filters from a dedicated 2.552.55m telescope, JST, at the Javalambre Astrophysical Observatory. Before the arrival of the final instrument (a 1.2 Gpixels, 4.2deg2^2 field-of-view camera), the JST was equipped with an interim camera (JPAS-Pathfinder), composed of one CCD with a 0.3deg2^2 field-of-view and resolution of 0.23 arcsec pixel1^{-1}. To demonstrate the scientific potential of J-PAS, with the JPAS-Pathfinder camera we carried out a survey on the AEGIS field (along the Extended Groth Strip), dubbed miniJPAS. We observed a total of 1\sim 1 deg2^2, with the 5656 J-PAS filters, which include 5454 narrow band (NB, FWHM145\rm{FWHM} \sim 145Angstrom) and two broader filters extending to the UV and the near-infrared, complemented by the u,g,r,iu,g,r,i SDSS broad band (BB) filters. In this paper we present the miniJPAS data set, the details of the catalogues and data access, and illustrate the scientific potential of our multi-band data. The data surpass the target depths originally planned for J-PAS, reaching magAB\rm{mag}_{\rm {AB}} between 22\sim 22 and 23.523.5 for the NB filters and up to 2424 for the BB filters (5σ5\sigma in a 33~arcsec aperture). The miniJPAS primary catalogue contains more than 64,00064,000 sources extracted in the rr detection band with forced photometry in all other bands. We estimate the catalogue to be complete up to r=23.6r=23.6 for point-like sources and up to r=22.7r=22.7 for extended sources. Photometric redshifts reach subpercent precision for all sources up to r=22.5r=22.5, and a precision of 0.3\sim 0.3% for about half of the sample. (Abridged

    The miniJPAS survey: A preview of the Universe in 56 colors

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    International audienceThe Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) will scan thousands of square degrees of the northern sky with a unique set of 56 filters using the dedicated 2.55 m Javalambre Survey Telescope (JST) at the Javalambre Astrophysical Observatory. Prior to the installation of the main camera (4.2 deg2 field-of-view with 1.2 Gpixels), the JST was equipped with the JPAS-Pathfinder, a one CCD camera with a 0.3 deg2 field-of-view and plate scale of 0.23 arcsec pixel−1. To demonstrate the scientific potential of J-PAS, the JPAS-Pathfinder camera was used to perform miniJPAS, a ∼1 deg2 survey of the AEGIS field (along the Extended Groth Strip). The field was observed with the 56 J-PAS filters, which include 54 narrow band (FWHM ∼ 145 Å) and two broader filters extending to the UV and the near-infrared, complemented by the u, g, r, i SDSS broad band filters. In this miniJPAS survey overview paper, we present the miniJPAS data set (images and catalogs), as we highlight key aspects and applications of these unique spectro-photometric data and describe how to access the public data products. The data parameters reach depths of magAB ≃ 22−23.5 in the 54 narrow band filters and up to 24 in the broader filters (5σ in a 3″ aperture). The miniJPAS primary catalog contains more than 64 000 sources detected in the r band and with matched photometry in all other bands. This catalog is 99% complete at r = 23.6 (r = 22.7) mag for point-like (extended) sources. We show that our photometric redshifts have an accuracy better than 1% for all sources up to r = 22.5, and a precision of ≤0.3% for a subset consisting of about half of the sample. On this basis, we outline several scientific applications of our data, including the study of spatially-resolved stellar populations of nearby galaxies, the analysis of the large scale structure up to z ∼ 0.9, and the detection of large numbers of clusters and groups. Sub-percent redshift precision can also be reached for quasars, allowing for the study of the large-scale structure to be pushed to z > 2. The miniJPAS survey demonstrates the capability of the J-PAS filter system to accurately characterize a broad variety of sources and paves the way for the upcoming arrival of J-PAS, which will multiply this data by three orders of magnitude.Key words: surveys / techniques: photometric / astronomical databases: miscellaneous / stars: general / galaxies: general / cosmology: observations⋆ miniJPAS data and associated value added catalogs are publicly available http://archive.cefca.es/catalogues/minijpas-pdr20191

    Grams ME, Sang Y, Ballew SH, et al, for the Chronic Kidney Disease Prognosis Consortium. Predicting timing of clinical outcomes in patients with chronic kidney disease and severely decreased glomerular filtration rate. Kidney Int. 2018;93:1442–1451

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    International audienceFirst-line therapy of minimal change nephrotic syndrome (MCNS) in adults is extrapolated largely from pediatric studies and consists of high-dose oral corticosteroids. We assessed whether a low corticosteroid dose combined with mycophenolate sodium was superior to a standard oral corticosteroid regimen. We enrolled 116 adults with MCNS in an open-label randomized controlled trial involving 32 French centers. Participants randomly assigned to the test group (n=58) received low-dose prednisone (0.5 mg/kg/day, maximum 40 mg/day) plus enteric-coated mycophenolate sodium 720 mg twice daily for 24 weeks; those who did not achieve complete remission after week 8 were eligible for a second-line regimen (increase in the prednisone dose to 1 mg/kg/day with or without Cyclosporine). Participants randomly assigned to the control group (n=58) received conventional high-dose prednisone (1 mg/kg/day, maximum 80 mg/day) for 24 weeks. The primary endpoint of complete remission after four weeks of treatment was ascertained in 109 participants, with no significant difference between the test and control groups. Secondary outcomes, including remission after 8 and 24 weeks of treatment, did not differ between the two groups. During 52 weeks of follow-up, MCNS relapsed in 15 participants (23.1%) who had achieved the primary outcome. Median time to relapse was similar in the test and control groups (7.1 and 5.1 months, respectively), as was the incidence of serious adverse events. Five participants died from hemorrhage (n=2) or septic shock (n=3), including 2 participants in the test group and 3 in the control group. Thus, in adult patients, treatment with low-dose prednisone plus enteric-coated mycophenolate sodium was not superior to a standard high-dose prednisone regimen to induce complete remission of MCNS

    Global, regional, and national levels of maternal mortality, 1990–2015:a systematic analysis for the Global Burden of Disease Study 2015

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