NGC 6705 a young α\alpha-enhanced Open Cluster from OCCASO data

The stellar [$\alpha$/Fe] abundance is sometimes used as a proxy for stellar age, following standard chemical evolution models for the Galaxy, as seen by different observational results. In this work we show that the Open Cluster NGC6705/M11 has a significant $\alpha$-enhancement [$\alpha$/Fe]$>0.1$ dex, despite its young age ($\sim$300 Myr), challenging the current paradigm. We use high resolution (R$>65,000$) high signal-to-noise ($\sim$70) spectra of 8 Red Clump stars, acquired within the OCCASO survey. We determine very accurate chemical abundances of several $\alpha$ elements, using an equivalent width methodology (Si, Ca and Ti), and spectral synthesis fits (Mg and O). We obtain [Si/Fe]=$0.13\pm0.05$, [Mg/Fe]=$0.14\pm0.07$, [O/Fe]=$0.17\pm0.07$, [Ca/Fe]=$0.06\pm0.05$ and [Ti/Fe]=$0.03\pm0.03$. Our results place these cluster within the group of young [$\alpha$/Fe]-enhanced field stars recently found by several authors in the literature. The ages of our stars have an uncertainty of around 50 Myr, much more precise than for field stars. By integrating the cluster's orbit in several non-axisymmetric Galactic potentials, we establish the M11's most likely birth radius to lie between 6.8-7.5 kpc from the Galactic center, not far from its current position. With the robust Open Cluster age scale, our results prove that a moderate [$\alpha$/Fe]-enhancement is no guarantee for a star to be old, and that not all $\alpha$-enhanced stars can be explained with an evolved blue straggler scenario. Based on our orbit calculations, we further argue against a Galactic bar origin of M11.Comment: 10 pages, 6 figures, accepted in A&

Médano La Enriqueta: un lugar de entierro de cazadores tardíos sobre el río Colorado (Dpto. Caleu Caleu, provincia de La Pampa)

This paper presents the first results obtained on bioarchaeological and cultural evidence recovered at Médano La Enriqueta I site (MLE-I). This site is a case of human prehispanic settlement in the southern area of Caleu-Caleu Department. MLE-I is located on an active dune, in which three hollows, were found, probably related with the differential use of space by prehispanic hunter-gatherers societies, were found. human remains were recovered from one of these hollows, while in another the cultural record is a consequence of other human activities. From the archaeological analysis it was possible to estimate a MNI of nine. Two skulls with intentional deformation (tabular erect type, planolambdic variant) were recovered, whose radiocarbon chronology, assigned to the final late holocene (1005±25 years bp), agrees with other cases known in the area. Finally, a remarkable variability of cultural remains, mainly represented by lithic artifacts, pottery fragments and malacological beads (chaquiras), were recovered. The data obtained by applying different lines of analysis are discussed and integrated with previous research developed in northern Patagonia and southern La Pampa Province.En este trabajo se presentan los primeros resultados obtenidos sobre las evidencias bioarqueológicas y culturales recuperadas en el sitio Médano La Enriqueta I (MLE-I). Este sitio constituye una manifestación de asentamiento prehispánico del sector sur del departamento Caleu-Caleu. MLE-I se localiza sobre un médano activo, en el cual se identificaron tres hoyadas que se corresponden con sectores de uso diferencial del espacio por parte de las poblaciones prehispánicas. En una de ellas se detectaron inhumaciones de restos humanos, mientras que en otra el registro recuperado sugiere actividades diversas. A partir del análisis del conjunto esqueletal, fue posible identificar un NMI de 9. Se destacan dos cráneos con deformación intencional de tipo tabular erecta, variante planolámbdica, cuya cronología radiocarbónica, asignada al Holoceno tardío final (1005±25 años ap), concuerda con otros casos identificados. Se recuperó también una destacada variabilidad de restos culturales principalmente representados por artefactos líticos, fragmentos cerámicos y restos malacológicos. Los datos obtenidos a partir de la implementación de diferentes líneas de análisis son discutidos e integrados con los antecedentes del norte de Patagonia y sur de la provincia de La Pampa

How are the ancient cystic fibrosis patients?: Cystic fibrosis diagnosed over 60 years-old

Background and aims To specify the prevalence of patients diagnosed with CF at age of ≥60 year-old and to analyze their characteristics. Patients and methods Observational study of CF patients which were diagnosed at age ≥60 year-old. The analyzed variables were: age, sex, nationality, lung function parameters, conditions present at diagnosis, microbiological characteristics and genetic findings. Results eight patients were included. 7 patients were female (87.5%) with a mean age of 70.6 years (median 71.5 years, range 60–78 years). The most important findings were: sweat test > 60 mEq/l; heterozygotes F508del; bronchiectasis in CT; methicillin-sensitive Staphylococcus aureus (50%) in sputum. The most patients presented a normal or mild obstructive lung function. Conclusions CF must also be considered a disease diagnosed in adulthood, incorporating the sweat test within the usual techniques of differential diagnosis in patients with different diseases associated with CF, because genetic counselling is esencial

Probabilistic multi-catalogue positional cross-match

[Context]: Catalogue cross-correlation is essential to building large sets of multi-wavelength data, whether it be to study the properties of populations of astrophysical objects or to build reference catalogues (or timeseries) from survey observations. Nevertheless, resorting to automated processes with limited sets of information available on large numbers of sources detected at different epochs with various filters and instruments inevitably leads to spurious associations. We need both statistical criteria to select detections to be merged as unique sources, and statistical indicators helping in achieving compromises between completeness and reliability of selected associations. [Aims]: We lay the foundations of a statistical framework for multi-catalogue cross-correlation and cross-identification based on explicit simplified catalogue models. A proper identification process should rely on both astrometric and photometric data. Under some conditions, the astrometric part and the photometric part can be processed separately and merged a posteriori to provide a single global probability of identification. The present paper addresses almost exclusively the astrometrical part and specifies the proper probabilities to be merged with photometric likelihoods. [Methods]: To select matching candidates in n catalogues, we used the Chi (or, indifferently, the Chi-square) test with 2(n-1) degrees of freedom. We thus call this cross-match a χ-match. In order to use Bayes' formula, we considered exhaustive sets of hypotheses based on combinatorial analysis. The volume of the χ-test domain of acceptance-a 2(n-1)-dimensional acceptance ellipsoid-is used to estimate the expected numbers of spurious associations. We derived priors for those numbers using a frequentist approach relying on simple geometrical considerations. Likelihoods are based on standard Rayleigh, χ and Poisson distributions that we normalized over the χ-test acceptance domain. We validated our theoretical results by generating and cross-matching synthetic catalogues. [Results]: The results we obtain do not depend on the order used to cross-correlate the catalogues. We applied the formalism described in the present paper to build the multi-wavelength catalogues used for the science cases of the Astronomical Resource Cross-matching for High Energy Studies (ARCHES) project. Our cross-matching engine is publicly available through a multi-purpose web interface. In a longer term, we plan to integrate this tool into the CDS XMatch Service.A large part of this work was supported by the ARCHES project. ARCHES (No. 313146) was funded by the 7th Framework of the European Union and coordinated by the University of Strasbourg. . F. J. Carrera also acknowledges financial support through grant AYA2015-64346-C2-1-P (MINECO/FEDER).Peer Reviewe

An 8-mm diameter fibre robot positioner for massive spectroscopy surveys

This article has been accepted for publication in Monthly Notices of Royal Astronomical Society © 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reservedMassive spectroscopic survey are becoming trendy in astrophysics and cosmology, as they can address new fundamental knowledge such as understanding the formation of the Milky Way and probing the nature of the mysterious dark energy. To enable massive spectroscopic surveys, new technology has been developed to place thousands of optical fibres at a given position on a focal plane. This technology needs to be: (1) accurate, with micrometer positional accuracy; (2) fast to minimize overhead; (3) robust to minimize failure; and (4) low cost. In this paper, we present the development, properties, and performance of a new single 8-mm in diameter fibre positioner robot, using two 4-mm DC-brushless gearmotors, that allows us to achieve accuracies up to 0.07 arcsec (5 μm). This device has been developed in the context of the Dark Energy Spectroscopic InstrumentWe acknowledge support from the Spanish MICINNs Consolider-Ingenio 2010 Program me under grant MultiDark CSD2009-00064, HEPHACOS S2009/ESP-1473, and MINECO Centro de Excelencia Severo Ochoa Programme under grant SEV-2012-0249. We also thank the support from a CSIC-AVS contract through MICINN grant AYA2010-21231-C02- 01, and CDTI grant IDC-20101033; and support from the Spanish MINECO research grants AYA2012-31101 and FPA2012-34694. JPK, PH and LM acknowledge support from the ERC advanced grant LIDA and from an SNF Interdisciplinary grant

Search for dark photons from supersymmetric hidden valleys

We search for a new light gauge boson, a dark photon, with the D0 experiment. In the model we consider, supersymmetric partners are pair produced and cascade to lightest neutralinos that can decay into the hidden sector state plus either a photon or a dark photon. The dark photon decays through its mixing with a photon into fermion pairs. We therefore investigate a previously unexplored final state that contains a photon, two spatially close leptons, and large missing transverse energy. We do not observe any evidence for dark photons and set a limit on their production.Comment: submitted to PR

Measurement of Z/gamma*+jet+X angular distributions in ppbar collisions at sqrt{s}=1.96 TeV

We present the first measurements at a hadron collider of differential cross sections for Z+jet+X production in delta phi(Z, jet), |delta y(Z, jet)| and |y_boost(Z, jet)|. Vector boson production in association with jets is an excellent probe of QCD and constitutes the main background to many small cross section processes, such as associated Higgs production. These measurements are crucial tests of the predictions of perturbative QCD and current event generators, which have varied success in describing the data. Using these measurements as inputs in tuning event generators will increase the experimental sensitivity to rare signals.Comment: Published in Physics Letters B 682 (2010), pp. 370-380. 15 pages, 6 figure