Rubidium and zirconium abundances in massive Galactic asymptotic giant branch stars revisited

Luminous Galactic OH/IR stars have been identified as massive (>4-5 M_s) AGB stars experiencing HBB and Li production. Their Rb abundances and [Rb/Zr] ratios derived from hydrostatic model atmospheres, are significantly higher than predictions from AGB nucleosynthesis models, posing a problem to our understanding of AGB evolution and nucleosynthesis. We report new Rb and Zr abundances in the full sample of massive Galactic AGB stars, previously studied with hydrostatic models, by using more realistic extended model atmospheres. We use a modified version of the spectral synthesis code Turbospectrum and consider the presence of a circumstellar envelope and radial wind. The Rb and Zr abundances are determined from the 7800 A Rb I resonant line and the 6474 A ZrO bandhead, respectively, and we explore the sensitivity of the derived abundances to variations of the stellar (Teff) and wind (M_loss, beta and vexp) parameters in the extended models. The Rb and Zr abundances derived from the best spectral fits are compared with the most recent AGB nucleosynthesis theoretical models. The new Rb abundances are much lower (even 1-2 dex) than those derived with the hydrostatic models, while the Zr abundances are similar. The Rb I line profile and Rb abundance are very sensitive to the M_loss rate but much less sensitive to variations of the wind velocity-law and the vexp(OH). We confirm the earlier preliminary results based on a smaller sample of massive O-rich AGB stars, that the use of extended atmosphere models can solve the discrepancy between the AGB nucleosynthesis theoretical models and the observations of Galactic massive AGB stars. The Rb abundances, however, are still strongly dependent of the M_loss, which is unknown in these AGB stars. Accurate M_loss rates in these massive Galactic AGB stars are needed in order to break the models degeneracy and get reliable Rb abundances in these stars.Comment: Accepted for publication in A&A, 14 pages, 12 figures, 4 table

Analysis of the performance of a hybrid CPU/GPU 1D2D coupled model for real flood cases

Coupled 1D2D models emerged as an efficient solution for a two-dimensional (2D) representation of the floodplain combined with a fast one-dimensional (1D) schematization of the main channel. At the same time, high-performance computing (HPC) has appeared as an efficient tool for model acceleration. In this work, a previously validated 1D2D Central Processing Unit (CPU) model is combined with an HPC technique for fast and accurate flood simulation. Due to the speed of 1D schemes, a hybrid CPU/GPU model that runs the 1D main channel on CPU and accelerates the 2D floodplain with a Graphics Processing Unit (GPU) is presented. Since the data transfer between sub-domains and devices (CPU/GPU) may be the main potential drawback of this architecture, the test cases are selected to carry out a careful time analysis. The results reveal the speed-up dependency on the 2D mesh, the event to be solved and the 1D discretization of the main channel. Additionally, special attention must be paid to the time step size computation shared between sub-models. In spite of the use of a hybrid CPU/GPU implementation, high speed-ups are accomplished in some cases

Active galactic nuclei synapses: X-ray versus optical classifications using artificial neural networks

(Abridged) Many classes of active galactic nuclei (AGN) have been defined entirely throughout optical wavelengths while the X-ray spectra have been very useful to investigate their inner regions. However, optical and X-ray results show many discrepancies that have not been fully understood yet. The aim of this paper is to study the "synapses" between the X-ray and optical classifications. For the first time, the new EFLUXER task allowed us to analyse broad band X-ray spectra of emission line nuclei (ELN) without any prior spectral fitting using artificial neural networks (ANNs). Our sample comprises 162 XMM-Newton/pn spectra of 90 local ELN in the Palomar sample. It includes starbursts (SB), transition objects (T2), LINERs (L1.8 and L2), and Seyferts (S1, S1.8, and S2). The ANNs are 90% efficient at classifying the trained classes S1, S1.8, and SB. The S1 and S1.8 classes show a wide range of S1- and S1.8-like components. We suggest that this is related to a large degree of obscuration at X-rays. The S1, S1.8, S2, L1.8, L2/T2/SB-AGN (SB with indications of AGN), and SB classes have similar average X-ray spectra within each class, but these average spectra can be distinguished from class to class. The S2 (L1.8) class is linked to the S1.8 (S1) class with larger SB-like component than the S1.8 (S1) class. The L2, T2, and SB-AGN classes conform a class in the X-rays similar to the S2 class albeit with larger fractions of SB-like component. This SB-like component is the contribution of the star-formation in the host galaxy, which is large when the AGN is weak. An AGN-like component seems to be present in the vast majority of the ELN, attending to the non-negligible fraction of S1-like or S1.8-like component. This trained ANN could be used to infer optical properties from X-ray spectra in surveys like eRosita.Comment: 15 pages, 7 figures, accepted for publication in A&A. Appendix B only in the full version of the paper here: https://dl.dropboxusercontent.com/u/3484086/AGNSynapsis_OGM_online.pd

Hot bottom burning and s-process nucleosynthesis in massive AGB stars at the beginning of the thermally-pulsing phase

We report the first spectroscopic identification of massive Galactic asymptotic giant branch (AGB) stars at the beginning of the thermal pulse (TP) phase. These stars are the most Li-rich massive AGBs found to date, super Li-rich AGBs with logE(Li)~3-4. The high Li overabundances are accompanied by weak or no s-process element (i.e. Rb and Zr) enhancements. A comparison of our observations with the most recent hot bottom burning (HBB) and s-process nucleosynthesis models confirms that HBB is strongly activated during the first TPs but the 22Ne neutron source needs many more TP and third dredge-up episodes to produce enough Rb at the stellar surface. We also show that the short-lived element Tc, usually used as an indicator of AGB genuineness, is not detected in massive AGBs which is in agreement with the theoretical predictions when the 22Ne neutron source dominates the s-process nucleosynthesis.Comment: Accepted for publication in Astronomy & Astrophysics Letters (7 pages, 5 figures and 1 table); final version (language corrected

A deterministic detector for vector vortex states

Encoding information in high-dimensional degrees of freedom of photons has led to new avenues in various quantum protocols such as communication and information processing. Yet to fully benefit from the increase in dimension requires a deterministic detection system, e.g., to reduce dimension dependent photon loss in quantum key distribution. Recently, there has been a growing interest in using vector vortex modes, spatial modes of light with entangled degrees of freedom, as a basis for encoding information. However, there is at present no method to detect these non-separable states in a deterministic manner, negating the benefit of the larger state space. Here we present a method to deterministically detect single photon states in a four dimensional space spanned by vector vortex modes with entangled polarisation and orbital angular momentum degrees of freedom. We demonstrate our detection system with vector vortex modes from the |[Formula: see text]| = 1 and |[Formula: see text]| = 10 subspaces using classical and weak coherent states and find excellent detection fidelities for both pure and superposition vector states. This work opens the possibility to increase the dimensionality of the state-space used for encoding information while maintaining deterministic detection and will be invaluable for long distance classical and quantum communication

Evaluación de la información sanitaria disponible en Internet sobre las recomendaciones de vacunación frente al Meningococo B

Fundamentos. La calidad de la información sanitaria en internet preocupa a gobiernos y usuarios. Nuestro objetivo fue determinar en qué medida la información disponible en la red sobre las recomendaciones de vacunación frente al meningococo B se adhiere a lo indicado por el Ministerio de Sanidad español. Métodos. Estudio transversal realizado en abril de 2017. Se evaluó la adhesión de la información sobre recomendaciones de recibir la vacuna. La información se obtuvo a través de Google utilizando veinte palabras clave. Se utilizó la prueba chi-cuadrado para estudiar la asociación entre obtener información adherida y el tipo de origen de la misma. Resultados. Se analizaron 186 enlaces web. Se detectaron recomendaciones adheridas entre el 52, 2% (97/186) de los enlaces para la indicación en personas con deficiencia de properdina/factores terminales del complemento, y el 79, 6% para las situaciones de brotes. Vacunar a niños a partir de los dos meses de edad fue una recomendación no elaborada por el Ministerio que se detectó en el 72, 6% de los enlaces. Para cada una de las recomendaciones del Ministerio, los organismos oficiales de salud pública siempre proporcionaron información adherida. Medios de comunicación digitales aportaron con una frecuencia significativamente mayor, que las Sociedades Científicas, información adherida sobre vacunar a personas con deficiencia de properdina/factores terminales del complemento (OR: 2, 72; IC95%: 1, 18-6, 28) y asplenia (OR: 3, 83; IC95%: 1, 66-8, 86). Conclusiones. Se evidencia una dificultad para obtener información adherida a lo indicado por la ponencia de vacunación del Ministerio de Sanidad, Servicios Sociales e Igualdad. Se debe promocionar en los usuarios la consulta de páginas web de organismos oficiales de salud pública cuando busquen información sobre esta vacuna. Background. The quality of health information online is a concern to governments and users. Our objective was to determine the extent to which the information available online regarding meningococcal B vaccine recommendations adhere to the guidelines of the Spanish Ministry of Health. Methods. Cross-sectional study carried out in April 2017. The study assessed adherence of information regarding vaccine recommendations to official guidelines. The information was collected via Google with 20 keywords. The Chi-squared test was used to analyze the association between the adhered information and its origin. Results. In total, 186 web links were analyzed. Adhered recommendations were found in a range of links, from 52.2% (97/186) with an indication for people with properdin deficiency/termial component pathway deficiency, to 79.6% for outbreak situations. Vaccinating children from two months of age was a recommendation not issued by the Ministry that was found in 72.6% of the links. For each of the Ministry recommendations, official public health institutions always provide information adhering to them. Digital media provided information about vaccination adhering to official guidelines with a significantly higher frequency than scientific societies in cases of people with . properdin deficiency/terminal component pathway deficiency (OR: 2.72; 95%CI: 1.186.28) and asplenia (OR: 3.83; 95%CI: 1.66-8.86). Conclusions. We have observed a difficulty to obtain adhered information. Users must be encouraged to access websites of official public health institutions when looking for information about this vaccine