741 research outputs found

    Absolute Calibration of the Auger Fluorescence Detectors

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    Absolute calibration of the Pierre Auger Observatory fluorescence detectors uses a light source at the telescope aperture. The technique accounts for the ombined effects of all detector components in a single measurement. The calibrated 2.5 m diameter light source fills the aperture, providing uniform illumination to each pixel. The known flux from the light source and the response of the acquisition system give the required calibration for each pixel. In the lab, light source uniformity is studied using CCD images and the intensity is measured relative to NIST-calibrated photodiodes. Overall uncertainties are presently 12%, and are dominated by systematics.Comment: 4 pages, 3 figure. Submitted to the 29th ICRC, Pune, Indi

    Multi-wavelength Calibration Procedure for the Pierre Auger Observatory Fluorescence Detectors

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    We present a method to measure the relative spectral response of the Pierre Auger Observatory Fluorescence Detector. The calibration was done at wavelengths of 320, 337, 355, 380 and 405 nm using an end-to-end technique in which the response of all detector components are combined in a single measurement. A xenon flasher and notch-filters were used as the light source for the calibration device. The overall uncertainty is 5%.Comment: Submitted to Astroparticle Physics. V2: section 5.2 extended; author list change

    Crescimento inicial de Mimosa scabrella Benth., Schinus terebinthifolius Raddi e Allophylus edulis (St. Hill) Radl. sob diferentes regimes de adubação.

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    O presente trabalho estudou a produção de mudas em viveiro envolvendo as espécies Mimosa scabrella Benth. (bracatinga), Schinus terebinthifolius Raddi (aroeira-vermelha) e Allophylus edulis (ST Hil.) Radl (vacum). O experimento foi conduzido no Município de Colombo, PR, no viveiro da Embrapa Florestas. Em fevereiro de 2004, foi realizada a semeadura das três espécies, em tubetes com cerca de 50 cm3, preenchidos com 70% de substrato comercial a base de casca de pínus e vermiculita e 30% de fibra de coco granulada. Os tratamentos corresponderam à três diferentes dosagens de adubos, parceladas em adubação de base e de cobertura, dispostos em blocos ao acaso, com parcelas de nove mudas e sete repetições, correspondendo a 63 mudas por espécie/tratamento. Aos quatro meses após a semeadura, foi realizada a avaliação do experimento, com medições de altura e diâmetro do caule de todas as mudas, e selecionada uma muda por repetição para as análises destrutivas de biomassa seca (parte aérea e radicial), tendo como critério a escolha da muda mais próxima da média da repetição. A aroeira-vermelha foi a espécie que melhor respondeu à adubação, seguida da bracatinga. Diferentemente das demais espécies, o vacum apresentou baixa exigência quanto à adubação no processo de produção de mudas. O crescimento das espécies pode ter sido mais lento devido à época do ano, que envolveu o inverno

    The new carbon symbiotic star IPHAS J205836.43+503307.2

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    We are performing a search for symbiotic stars using IPHAS, the INT Halpha survey of the northern Galactic plane, and follow-up observations. Candidate symbiotic stars are selected on the basis of their IPHAS and near-IR colours, and spectroscopy and photometry are obtained to determine their nature. We present here observations of the symbiotic star candidate IPHAS J205836.43+503307.2. The optical spectrum shows the combination of a number of emission lines, among which are the high-excitation species of [OIII], HeII, [Ca V], and [Fe VII], and a red continuum with the features of a star at the cool end of the carbon star sequence. The nebular component is spatially resolved: the analysis of the spatial profile of the [NII]6583 line in the spectrum indicates a linear size of ~2.5 arcsec along the east-west direction. Its velocity structure suggests an aspherical morphology. The near-infrared excess of the source, which was especially strong in 1999, indicated that a thick circumstellar dust shell was also present in the system. The carbon star has brightened in the last decade by two to four magnitudes at red and near-infrared wavelengths. Photometric monitoring during a period of 60 days from November 2010 to January 2011 reveals a slow luminosity decrease of 0.2 magnitudes. From the observed spectrophotometric properties and variability, we conclude that the source is a new Galactic symbiotic star of the D-type, of the rare kind that contains a carbon star, likely a carbon Mira. Only two other systems of this type are known in the Galaxy.Comment: 6 pages, 4 figure
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