The influence of microlensing on the shape of the AGN Fe K-alpha line

We study the influence of gravitational microlensing on the AGN Fe K-alpha line confirming that unexpected enhancements recently detected in the iron line of some AGNs can be produced by this effect. We use a ray tracing method to study the influence of microlensing in the emission coming from a compact accretion disc considering both geometries, Schwarzschild and Kerr. Thanks to the small dimensions of the region producing the AGN Fe K-alpha line, the Einstein Ring Radii associated to even very small compact objects have size comparable to the accretion disc hence producing noticeable changes in the line profiles. Asymmetrical enhancements contributing differently to the peaks or to the core of the line are produced by a microlens, off-centered with respect to the accretion disc. In the standard configuration of microlensing by a compact object in an intervening galaxy, we found that the effects on the iron line are two orders of magnitude larger than those expected in the optical or UV emission lines. In particular, microlensing can satisfactorily explain the excess in the iron line emission found very recently in two gravitational lens systems, H 1413+117 and MG J0414+0534. Exploring other physical {scenario} for microlensing, we found that compact objects (of the order of one Solar mass) which belong to {the bulge or the halo} of the host galaxy can also produce significant changes in the Fe K$_\alpha$ line profile of an AGN. However, the optical depth estimated for this type of microlensing is {very small, $\tau\sim 0.001$, even in a favorable case.Comment: Astron. Astrophys. accepte

The high-pressure behavior of CaMoO4

We report a high-pressure study of tetragonal scheelite-type CaMoO4 up to 29 GPa. In order to characterize its high-pressure behavior, we have combined Raman and optical-absorption measurements with density-functional theory calculations. We have found evidence of a pressure-induced phase transition near 15 GPa. Experiments and calculations agree in assigning the high-pressure phase to a monoclinic fergusonite-type structure. The reported results are consistent with previous powder x-ray-diffraction experiments, but are in contradiction with the conclusions obtained from earlier Raman measurements, which support the existence of more than one phase transition in the pressure range covered by our studies. The observed scheelite-fergusonite transition induces significant changes in the electronic band gap and phonon spectrum of CaMoO4. We have determined the pressure evolution of the band gap for the low- and high-pressure phases as well as the frequencies and pressure dependences of the Raman-active and infrared-active modes. In addition, based upon calculations of the phonon dispersion of the scheelite phase, carried out at a pressure higher than the transition pressure, we propose a possible mechanism for the reported phase transition. Furthermore, from the calculations we determined the pressure dependence of the unit-cell parameters and atomic positions of the different phases and their room-temperature equations of state. These results are compared with previous experiments showing a very good agreement. Finally, information on bond compressibility is reported and correlated with the macroscopic compressibility of CaMoO4. The reported results are of interest for the many technological applications of this oxide.Comment: 36 pages, 10 figures, 8 table

Effectiveness of a participatory approach for collection of economic data in aquaculture systems at farm level in Brazil.

This paper aims to evaluate the effectiveness of a participatory approach which is currently being applied by the Brazilian Agricultural Research Corporation (Embrapa) and Brazilian Confederation of Agriculture and Livestock (CNA) in aquaculture sector in Brazil

An X-ray study of the SNR G344.7-0.1 and the central object CXOU J170357.8-414302

Aims. We report results of an X-ray study of the supernova remnant (SNR) G344.7-0.1 and the point-like X-ray source located at the geometrical center of the SNR radio structure. Methods. The morphology and spectral properties of the remnant and the central X-ray point-like source were studied using data from the XMM-Newton and Chandra satellites. Archival radio data and infrared Spitzer observations at 8 and 24 $\mu$m were used to compare and study its multi-band properties at different wavelengths. Results. The XMM-Newton and Chandra observations reveal that the overall X-ray emission of G344.7-0.1 is extended and correlates very well with regions of bright radio and infrared emission. The X-ray spectrum is dominated by prominent atomic emission lines. These characteristics suggest that the X-ray emission originated in a thin thermal plasma, whose radiation is represented well by a plane-parallel shock plasma model (PSHOCK). Our study favors the scenario in which G344.7-0.1 is a 6 x 10^3 year old SNR expanding in a medium with a high density gradient and is most likely encountering a molecular cloud on the western side. In addition, we report the discovery of a soft point-like X-ray source located at the geometrical center of the radio SNR structure. The object presents some characteristics of the so-called compact central objects (CCO). However, its neutral hydrogen absorption column (N_{H}) is inconsistent with that of the SNR. Coincident with the position of the source, we found infrared and optical objects with typical early-K star characteristics. The X-ray source may be a foreground star or the CCO associated with the SNR. If this latter possibility were confirmed, the point-like source would be the farthest CCO detected so far and the eighth member of the new population of isolated and weakly magnetized neutron stars.Comment: 9 pages, 8 figures, accepted for publication in Astronomy and Astrophysics. Higher resolution figures can be seen on A&

How to hide a secret direction

We present a procedure to share a secret spatial direction in the absence of a common reference frame using a multipartite quantum state. The procedure guarantees that the parties can determine the direction if they perform joint measurements on the state, but fail to do so if they restrict themselves to local operations and classical communication (LOCC). We calculate the fidelity for joint measurements, give bounds on the fidelity achievable by LOCC, and prove that there is a non-vanishing gap between the two of them, even in the limit of infinitely many copies. The robustness of the procedure under particle loss is also studied. As a by-product we find bounds on the probability of discriminating by LOCC between the invariant subspaces of total angular momentum N/2 and N/2-1 in a system of N elementary spins.Comment: 4 pages, 1 figur

Piscicultores e demais agentes da cadeia produtiva discutem os custos de produção da tilápia em Morada Nova de Minas.

No dia 01 de abril de 2016, em Morada Nova de Minas, região central de Minas Gerais, às margens da represa de Três Marias, foi realizado painel de levantamento de custos de produção do projeto Campo Futuro da Aquicultura sobre tilapicultura em tanque-rede. Este painel aconteceu no Sindicato Rural de Morada Nova de Minas e contou com treze participantes, entre produtores e demais agentes da cadeia produtiva da tilápia no município. O projeto Campo Futuro da Aquicultura é uma parceria entre a Confederação da Agricultura e Pecuária do Brasil (CNA) e a Empresa Brasileira de Pesquisa Agropecuária (Embrapa) e tem como objetivo levantar dados de Custo de Produção da Aquicultura em território nacional a fim de subsidiar a criação de políticas públicas para o setor e auxiliar os piscicultores no gerenciamento de seus empreendimentos aquícolas

Piscicultores e demais agentes da cadeia produtiva discutem os custos de produção da tilápia em Felixlândia.

No dia 31 de março de 2016, em Felixlândia, região central do estado de Minas Gerais, às margens da represa de Três Marias, foi realizado o segundo painel, do Projeto Campo Futuro da Aquicultura, sobre a tilapicultura em tanque-rede. O projeto é uma parceria entre a Confederação da Agricultura e Pecuária do Brasil (CNA) e a Empresa Brasileira de Pesquisa Agropecuária (Embrapa). Este foi o segundo painel de 2016, aconteceu no Sindicato Rural de Felixlândia e contou com dez participantes, entre produtores e demais agentes da cadeia produtiva da tilápia no município. O projeto Campo Futuro da Aquicultura tem como objetivo levantar dados de Custo de Produção da Aquicultura em território nacional, a fim de subsidiar a criação de políticas públicas para o setor e auxiliar os piscicultores no gerenciamento de seus empreendimentos aquícolas.bitstream/item/145198/1/CNPASA-2016-icf20.pd

Piscicultores e demais agentes da cadeia produtiva discutem os custos de produção da tilápia em Guapé.

No dia 29 de março de 2016, em Guapé, região sudoeste de Minas Gerais, às margens da represa de Furnas, foi realizado painel do Projeto Campo Futuro da Aquicultura sobre a tilapicultura em tanquerede. O projeto é uma parceria entre a Confederação da Agricultura e Pecuária do Brasil (CNA) e a Empresa Brasileira de Pesquisa Agropecuária (Embrapa). Este foi o primeiro painel de 2016, que aconteceu no Sindicato Rural de Guapé e contou com oito participantes, entre produtores e demais agentes da cadeia produtiva da tilápia no município. O projeto Campo Futuro da Aquicultura tem como objetivo levantar dados de Custo de Produção da Aquicultura em território nacional, a fim de subsidiar a criação de políticas públicas para o setor e auxiliar os piscicultores na administração de seus empreendimentos aquícolas.bitstream/item/145201/1/CNPASA-2016-icf19.pd