Telescope performance and image simulations of the balloon-borne coded-mask protoMIRAX experiment

In this work we present the results of imaging simulations performed with the help of the GEANT4 package for the protoMIRAX hard X-ray balloon experiment. The instrumental background was simulated taking into account the various radiation components and their angular dependence, as well as a detailed mass model of the experiment. We modeled the meridian transits of the Crab Nebula and the Galatic Centre region during balloon flights in Brazil ($\sim -23^{\circ}$ of latitude and an altitude of $\sim 40 \thinspace$ km) and introduced the correspondent spectra as inputs to the imaging simulations. We present images of the Crab and of three sources in the Galactic Centre region: 1E 1740.7-2942, GRS 1758-258 and GX 1+4. The results show that the protoMIRAX experiment is capable of making spectral and timing observations of bright hard X-ray sources as well as important imaging demonstrations that will contribute to the design of the MIRAX satellite mission.Comment: 9 figure

Confirming the thermal Comptonization model for black hole X-ray emission in the low-hard state

Hard X-ray spectra of black hole binaries in the low/hard state are well modeled by thermal Comptonization of soft seed photons by a corona-type region with $kT$\thinspace$\sim 50${\thinspace}keV and optical depth around 1. Previous spectral studies of 1E{\thinspace}1740.7$-$2942, including both the soft and the hard X-ray bands, were always limited by gaps in the spectra or by a combination of observations with imaging and non-imaging instruments. In this study, we have used three rare nearly-simultaneous observations of 1E{\thinspace}1740.7$-$1942 by both XMM-Newton and INTEGRAL satellites to combine spectra from four different imaging instruments with no data gaps, and we successfully applied the Comptonization scenario to explain the broadband X-ray spectra of this source in the low/hard state. For two of the three observations, our analysis also shows that, models including Compton reflection can adequately fit the data, in agreement with previous reports. We show that the observations can also be modeled by a more detailed Comptonization scheme. Furthermore, we find the presence of an iron K-edge absorption feature in one occasion, which confirms what had been previously observed by Suzaku. Our broadband analysis of this limited sample shows a rich spectral variability in 1E{\thinspace}1740.7$-$2942 at the low/hard state, and we address the possible causes of these variations. More simultaneous soft/hard X-ray observations of this system and other black-hole binaries would be very helpful in constraining the Comptonization scenario and shedding more light on the physics of these systems.Comment: 6 pages, two figures, accepted for publication in A&

Modelagem matemática da dinâmica temporal do HLB.

RESUMO: O Huanglongbing (HLB) e considerado atualmente a mais grave doença da citricultura nacional, devido aos enormes prejuízos econômicos que pode causar. Este trabalho apresenta um modelo matemático epidemiológico para avaliar a evolução temporal da doença considerando o sistema planta (citros) - inseto vetor (Diaphorina citri). Com base na literatura determinou-se faixas de variacao para os parâmetros biológicos do modelo. A partir da criação de cenários de simulação verificou-se numericamente algumas condições que favorecem a evolução da doença.SBIAgro 2011

Manual de reconhecimento e controle das principais pragas do antúrio no Estado do Ceará.

Introdução; fungos gnats Bradysia sp. (Diptera: Sciaridae); pulgões Myzus ascalonicus Doncaster e Aphis fabae Scopoli (Hemiptera: Aphididae); Cochonilhas (Hemiptera: Diaspididae); Tripes Scirtothrips sp. (Thysanoptera: Thripidae); lagarta Phyciodes sp. (Lepidoptera: Nymphalidae); ácaros Tetranychus sp. (Acari: Tetranychidae); literatura recomendada.bitstream/CNPAT-2010/10887/1/Dc-114.pd