5,543 research outputs found

    Altitude Limits for Rotating Vector Model Fitting of Pulsar Polarization

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    Traditional pulsar polarization sweep analysis starts from the point dipole rotating vector model (RVM) approximation. If augmented by a measurement of the sweep phase shift, one obtains an estimate of the emission altitude (Blaskiewicz, Cordes, & Wasserman). However, a more realistic treatment of field line sweepback and finite altitude effects shows that this estimate breaks down at modest altitude ~ 0.1R_{LC}. Such radio emission altitudes turn out to be relevant to the young energetic and millisecond pulsars that dominate the \gamma-ray population. We quantify the breakdown height as a function of viewing geometry and provide simple fitting formulae that allow observers to correct RVM-based height estimates, preserving reasonable accuracy to R ~ 0.3R_{LC}. We discuss briefly other observables that can check and improve height estimates

    First Astronomical Application of a Cryogenic TES Spectrophotometer

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    We report on the first astronomical observations with a photon counting pixel detector that provides arrival time- (delta t = 100ns) and energy- (delta E_gamma < 0.15eV) resolved measurements from the near IR through the near UV. Our test observations were performed by coupling this Transition Edge Sensor (TES) device to a 0.6m telescope; we have obtained the first simultaneous optical near-IR phase-resolved spectra of the Crab pulsar. A varying infrared turnover gives evidence of self-absorption in the pulsar plasma. The potential of such detectors in imaging arrays from a space platform are briefly described.Comment: 4 pages, 5 figure

    Siger - orientações para interface gráfica.

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    Este documento tem por objetivo descrever as diretrizes para o projeto da interface de entrada de dados do Sistema de Informação Gerencial da Embrapa (SIGER), promovendo uma uniformidade visual dos elementos gráficos que o compoem. Como consequência desta uniformidade, espera-se que todo o SIGER possua o mesmo padrão de interface gráfica, o que irá facilitar a interacão do usuário com o sistema. São estabelecidas orientações para a disposição de elementos gráficos na tela e a definição de algumas das suas propriedades básicas. Algumas caracteristicas gerais do ambiente Windows sao mantidas na aplicação conforme a configuração definida pelo usuário, como exemplo cor das janelas ativa e inativa, texto da janela, texto da mensagem, cor do item de menu normal, desativado e selecionado.bitstream/item/76631/1/CNPTIA-COM.TEC.-4-98.pd
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