Spectral state dependence of the 0.4-2 MeV polarized emission in Cygnus X-1 seen with INTEGRAL/IBIS, and links with the AMI radio data

Polarization of the >~400 keV hard tail of the microquasar Cygnus X-1 has been independently reported by INTEGRAL/IBIS, and INTEGRAL/SPI and interpreted as emission from a compact jet. These conclusions were, however, based on the accumulation of all INTEGRAL data regardless of the spectral state. We utilize additional INTEGRAL exposure accumulated until December 2012, and include the AMI/Ryle (15 GHz) radio data in our study. We separate the observations into hard, soft, and intermediate/transitional states and detect radio emission from a compact jet in hard and intermediate states, but not in the soft. The 10-400 keV INTEGRAL (JEM-X and IBIS) state resolved spectra are well modeled with thermal Comptonization and reflection components. We detect a hard tail in the 0.4-2 MeV range for the hard state only. We extract the state dependent polarigrams of Cyg X-1, which all are compatible to no or undetectable level of polarization except in 400-2000 keV range in the hard state where the polarization fraction is 75$\pm$32 % and the polarization angle 40.0 +-14 deg. An upper limit on the 0.4-2 MeV soft state polarization fraction is 70%. Due to the short exposure, we obtain no meaningful constraint for the intermediate state. The likely detection of a >400 keV polarized tail in the hard state, together with the simultaneous presence of a radio jet, reinforce the notion of a compact jet origin of the 400 keV emission.Comment: 13 pages, 5 figures, accepted for publication in Ap

Vela X-1 as a laboratory for accretion in High-Mass X-ray Binaries

Vela X-1 is an eclipsing high mass X-ray binary (HMXB) consisting of a 283s accreting X-ray pulsar in a close orbit of 8.964 days around the B0.5Ib supergiant HD77581 at a distance of just 2.4 kpc. The system is considered a prototype of wind-accreting HMXB and it has been used as a baseline in different theoretical or modelling studies. We discuss the observational properties of the system and the use of the observational data as laboratory to test recent developments in modelling the accretion process in High-Mass X-ray Binaries (e.g., Sander et al. 2018; El Mellah et al. 2018), which range from detailed descriptions of the wind acceleration to modelling of the structure of the flow of matter close to the neutron star and its variations.Comment: 4 pages, 2 figures, proceedings of the 12th INTEGRAL conference "INTEGRAL looks AHEAD to Multimessenger astronomy" in Geneva (Switzerland) on 11-15 February 201

Avaliação do comportamento de estacas de Thitonia diversifolia (Hemsley) Gray em sistema agroflorestal na Encosta da Serra do Sudeste, RS.

O objetivo deste trabalho foi avaliar a sobrevivência e produção de biomassa de estacas com diferentes diâmetros de Thitonia diversifolia em condições de campo, fornecendo dados capazes de orientarem a utilização desta planta em sistemas Agroflorestais na região da Encosta da Serra do Sudeste, Rio Grande do Sul

Espécies com potencial para cercas-vicas em SAF's da Região Sul do RS: estudo preliminar.

O presente trabalho tem como objetivo elencar espécies com potencial para cercas-vivas em Sistemas Agroflorestais da região Sul do RS, buscando contribuir para proteção de agroecossistemas. Com base em revisão bibliográfica realizada foram elencadas 81 espécies, das quais 10 foram selecionadas para maior aprofundamento e serão apresentadas neste estudo. Posteriormente estas espécies serão testadas e analisadas em campo. Abstract: The present study aims to list species with potential for living fences in agroforestry systems in southern RS, seeking to contribute to protection of agroecosystems. Based on the literature review were listed 81 species, of which 10 were selected for further deepening and will be presented in this study. Later these species will be tested and evaluated in the ground

Avaliação da superação de dormência de sementes de Cupania vernalis Cambess.

Cupania vernalis pertence à família Sapindaceae e é conhecida popularmente como camboatá. Suas sementes apresentam alto teor de umidade e são classificadas como recalcitrantes. Frente à dificuldade de armazenagem e na busca por métodos que acelerem a germinação e emergência, submeteu-se as sementes a diferentes tratamentos de superação de dormência. Foram testados os processos de escarificação, aquecimento em água quente a 50ºC por 5 minutos, desidratação a 40% e testemunha sem tratamento. As sementes tiveram o arilo removido antes da aplicação dos tratamentos. Para cada um dos tratamentos avaliou-se a emergência durante 30, 60 e 90 dias. O aquecimento em água quente a 50ºC por 5 minutos acelerou o processo de germinação, enquanto que o tratamento desidratação apresentou a menor emergência absoluta, ainda que não tenha provocado a total inviabilidade das sementes. Abstract: Cupania vernalis belongs to the family Sapindaceae and it is known than camboatá. Their seeds have high moisture content and are classified as recalcitrant. Facing the difficulty of storing and for methods to speed up germination and emergence, underwent the seeds to different treatments. Scarification, heating in hot water at 50ºc for 5 minutes, dehydration to 40% and control without treatment where tested. The seeds had the aril removed before application the treatments. For each one of the treatments was evaluated at 30, 60 and emergencies during 90 days. Heating in hot water at 50ºc for 5 minutes accelerated the process of germination, while treating dehydration presented the lowest absolute emergency, even though it has not caused the total impracticality of the seeds

Licenciamento de espécies florestais nativas em sistemas agroflorestais no contexto da agricultura familiar.

O estudo está sendo realizado em três agroecossistemas que participam do projeto de pesquisa ?Construção participativa de sistemas agroflorestais no território sul do Rio Grande do Sul ? Encosta da Serra do Sudeste?, onde foram implantadas unidades pedagógicas de sistemas agroflorestais (SAFs). O presente trabalho consiste em exercitar o processo de licenciamento de plantios florestais com espécies nativas. Para tanto, tem-se realizado revisão bibliográfica e de fontes secundárias, entrevistas com os agentes licenciadores e famílias agricultoras, com o intuito de esclarecer, problematizar e qualificar os procedimentos administrativos e legais para que um agricultor possa plantar, manejar e colher produtos madeireiros e não-madeireiros, oriundos de espécies florestais nativas, atendendo as exigências da legislação ambiental. Abstract The study was conducted in three agroecosystems that participate in the research project "construction development of agroforestry systems in the territory south of the Rio Grande do Sul - South East Side of the Sierra," where units were deployed teaching agroforestry systems (AFS). The present work consists in exercising the licensing process forest plantations with native species. For both, we have performed bibliographic review and secondary sources, interviews with the licensors and farming families, with the intention of clarify, problematize and qualify the administrative and legal procedures necessary for that a farmer to plant, manage and harvest timber and non-wood from native forest species, meeting the requirement of environmental legislation

Sustainability in astroparticle physics

The topic of sustainability is becoming increasingly important in research activities in astroparticle physics, both in existing and also in future instrument. At this year\u27s International cosmic ray conference (ICRC 2021) one session was dedicated to this topic. This publication will summarise the findings of this well-attended online session