Census of HII regions in NGC 6754 derived with MUSE: Constraints on the metal mixing scale

We present a study of the HII regions in the galaxy NGC 6754 from a two pointing mosaic comprising 197,637 individual spectra, using Integral Field Spectrocopy (IFS) recently acquired with the MUSE instrument during its Science Verification program. The data cover the entire galaxy out to ~2 effective radii (re ), sampling its morphological structures with unprecedented spatial resolution for a wide-field IFU. A complete census of the H ii regions limited by the atmospheric seeing conditions was derived, comprising 396 individual ionized sources. This is one of the largest and most complete catalogue of H ii regions with spectroscopic information in a single galaxy. We use this catalogue to derive the radial abundance gradient in this SBb galaxy, finding a negative gradient with a slope consistent with the characteristic value for disk galaxies recently reported. The large number of H ii regions allow us to estimate the typical mixing scale-length (rmix ~0.4 re ), which sets strong constraints on the proposed mechanisms for metal mixing in disk galaxies, like radial movements associated with bars and spiral arms, when comparing with simulations. We found evidence for an azimuthal variation of the oxygen abundance, that may be related with the radial migration. These results illustrate the unique capabilities of MUSE for the study of the enrichment mechanisms in Local Universe galaxies.Comment: 13 pages, 7 Figurs, accepted for publishing in A&

Reference normal values and design of a vision screening for 4 to 5 years old preschoolers

A vision screening program for preschool children of 4-5 years old was designed and analyzed. Information of the prevalence of ocular conditions among preschool children was obtained. The vision health of a group of 127 children was evaluated by a comprehensive examination in their own school. If a child failed one or more screening tests, he was referred to the ophthalmologist. Of the children screened in this study, 61% passed distance visual acuity and retinoscopy tests, 17% were referred to the ophthalmologist and 22% will be annually monitoring. Values of monocular/binocular acuity worse than 0.5/0.6 are too poor for 4 years old children, whereas these limits increase up to 0.6/0.8 for 5 years old children. In conclusion, the prevalence of undetected vision problems in preschool children has been clearly demonstrated. Vision screening programs in schools are highly recommended. Nevertheless, coordination among professionals conducting screening, school personnel and parents are needed to reach high levels of success. The results of this study validate an easy and fast battery of tests. The vision screening has been highly reliable because reference normal values have been defined by analyzing statistically the results of these tests. Se diseñó y analizó un screening visual en preescolares de 4-5 años de edad. Se obtuvo información de la prevalencia de las condiciones oculares entre estos preescolares. Se evaluó la salud visual de un grupo de 127 niños con un examen completo en su propia escuela. Si el niño fallaba uno o más test era referido al oftalmólogo. De los niños revisados en el estudio, el 61% superó los test de agudeza visual y retinoscopía, al 17% se le refirió al oftalmólogo y el 22% será controlado anualmente. Valores de agudeza monocular/binocular peores de 0.5/0.6 son demasiado bajos para niños de 4 años de edad, mientras que estos límites se incrementan a 0.6/0.8 para niños de 5 años. En conclusión, la prevalencia de problemas de visión sin detectar en niños preescolares ha sido claramente demostrada. Sin embargo, es necesaria la coordinación entre profesionales que realicen el screening, personal del colegio y padres para alcanzar niveles altos de éxito. Los resultados de este estudio validan una batería rápida de test. El screening visual ha sido altamente fiable porque los valores normales de referencia han sido definidos analizando estadísticamente los resultados de estos tests

SDSS IV MaNGA: Dependence of Global and Spatially Resolved SFR-M ∗ Relations on Galaxy Properties

Indexación: Scopus.The galaxy integrated Hα star formation rate-stellar mass relation, or SFR(global)-M ∗(global) relation, is crucial for understanding star formation history and evolution of galaxies. However, many studies have dealt with SFR using unresolved measurements, which makes it difficult to separate out the contamination from other ionizing sources, such as active galactic nuclei and evolved stars. Using the integral field spectroscopic observations from SDSS-IV MaNGA, we spatially disentangle the contribution from different Hα powering sources for ∼1000 galaxies. We find that, when including regions dominated by all ionizing sources in galaxies, the spatially resolved relation between Hα surface density (ΣHα(all)) and stellar mass surface density (Σ∗(all)) progressively turns over at the high Σ∗(all) end for increasing M ∗(global) and/or bulge dominance (bulge-to-total light ratio, B/T). This in turn leads to the flattening of the integrated Hα(global)-M ∗(global) relation in the literature. By contrast, there is no noticeable flattening in both integrated Hα(H ii)-M ∗(H ii) and spatially resolved ΣHα(H ii)-Σ∗(H ii) relations when only regions where star formation dominates the ionization are considered. In other words, the flattening can be attributed to the increasing regions powered by non-star-formation sources, which generally have lower ionizing ability than star formation. An analysis of the fractional contribution of non-star-formation sources to total Hα luminosity of a galaxy suggests a decreasing role of star formation as an ionizing source toward high-mass, high-B/T galaxies and bulge regions. This result indicates that the appearance of the galaxy integrated SFR-M ∗ relation critically depends on their global properties (M ∗(global) and B/T) and relative abundances of various ionizing sources within the galaxies.http://iopscience.iop.org/article/10.3847/1538-4357/aaa9bc/met

Laparoscopic Video Analysis for Training and Image Guided Surgery

Automatic analysis of Minimally Invasive Surgical video has the potential to drive new solutions for alleviating needs of safe and reproducible training programs, objective and transparent evaluation systems and navigation tools to assist surgeons and improve patient safety. Surgical video is an always available source of information, which can be used without any additional intrusive hardware in the operating room. This paper is focused on surgical video analysis methods and techniques. It describes authors' contributions in two key aspects, the 3D reconstruction of the surgical field and the segmentation and tracking of tools and organs based on laparoscopic video images. Results are given to illustrate the potential of this field of research, like the calculi of the 3D position and orientation of a tool from its 2D image, or the translation of a preoperative resection plan into a hepatectomy surgical procedure using the shading information of the image. Research efforts are required to further develop these technologies in order to harness all the valuable information available in any video-based surgery

Spectrophotometric analysis of GRB afterglow extinction curves with X-shooter

In this work we use gamma-ray burst (GRB) afterglow spectra observed with the VLT/X-shooter spectrograph to measure rest-frame extinction in GRB lines-of-sight by modeling the broadband near-infrared (NIR) to X-ray afterglow spectral energy distributions (SEDs). Our sample consists of nine Swift GRBs, eight of them belonging to the long-duration and one to the short-duration class. Dust is modeled using the average extinction curves of the Milky Way and the two Magellanic Clouds. We derive the rest-frame extinction of the entire sample, which fall in the range $0 \lesssim {\it A}_{\rm V} \lesssim 1.2$. Moreover, the SMC extinction curve is the preferred extinction curve template for the majority of our sample, a result which is in agreement with those commonly observed in GRB lines-of-sights. In one analysed case (GRB 120119A), the common extinction curve templates fail to reproduce the observed extinction. To illustrate the advantage of using the high-quality X-shooter afterglow SEDs over the photometric SEDs, we repeat the modeling using the broadband SEDs with the NIR-to-UV photometric measurements instead of the spectra. The main result is that the spectroscopic data, thanks to a combination of excellent resolution and coverage of the blue part of the SED, are more successful in constraining the extinction curves and therefore the dust properties in GRB hosts with respect to photometric measurements. In all cases but one the extinction curve of one template is preferred over the others. We show that the modeled values of the extinction and the spectral slope, obtained through spectroscopic and photometric SED analysis, can differ significantly for individual events. Finally we stress that, regardless of the resolution of the optical-to-NIR data, the SED modeling gives reliable results only when the fit is performed on a SED covering a broader spectral region.Comment: 17 pages, 7 figures, 4 tables, accepted for publication in Astronomy & Astrophysic

GRB 140606B/iPTF14bfu: Detection of shock-breakout emission from a cosmological γ -ray burst?

We present optical and near-infrared photometry of GRB 140606B (z = 0.384), and optical photometry and spectroscopy of its associated supernova (SN). The results of our modelling indicate that the bolometric properties of the SN (MNi = 0.4 ± 0.2 M·, Mej = 5 ± 2 M·, and EK = 2 ± 1 × 1052 erg) are fully consistent with the statistical averages determined for other γ -ray burst (GRB)-SNe. However, in terms of its γ -ray emission, GRB 140606B is an outlier of the Amati relation, and occupies the same region as low luminosity (ll) and short GRBs. The γ -ray emission in llGRBs is thought to arise in some or all events from a shock breakout (SBO), rather than from a jet. The measured peak photon energy (Ep ≈ 800 keV) is close to that expected for γ -rays created by an SBO (≳ 1 MeV). Moreover, based on its position in theMV ,p-Liso,γ plane and the EK-Γβ plane, GRB 140606B has properties similar to both SBO-GRBs and jetted-GRBs. Additionally, we searched for correlations between the isotropic γ -ray emission and the bolometric properties of a sample of GRB-SNe, finding that no statistically significant correlation is present. The average kinetic energy of the sample is ĒK = 2.1 × 1052 erg. All of the GRB-SNe in our sample, with the exception of SN 2006aj, are within this range, which has implications for the total energy budget available to power both the relativistic and non-relativistic components in a GRB-SN event. © 2015 The Authors

Neutron capture measurements with high efficiency detectors and the Pulse Height Weighting Technique

Neutron capture cross section measurements in time-of-flight facilities are usually performed by detecting the prompt γ-rays emitted in the capture reactions. One of the difficulties to be addressed in these measurements is that the emitted γ-rays may change with the neutron energy, and therefore also the detection efficiency. To deal with this situation, many measurements use the so called Total Energy Detection (TED) technique, usually in combination with the Pulse Height Weighting Technique (PHWT). With it, it is sought that the detection efficiency depends only on the total energy of the γ-ray cascade, which does not vary much with the neutron energy. This technique was developed in the 1960s and has been used in many neutron capture experiments to date. One of the requirements of the technique is that γ-ray detectors have a low efficiency. This has meant that the PHWT has been used with experimental setups with low detection efficiencies. However, this condition does not have to be fulfilled by the experimental system as a whole. The main goal of this work is to show that it is possible to measure with a high efficiency detection system that uses the PHWT, and how to analyze the measured data.This work was supported in part by the I+D+i grant PGC2018- 096717-B-C21 funded by MCIN/AEI/10.13039/501100011033 and by the European Commission H2020 Framework Programme project SANDA (Grant agreement ID: 847552)

Arm and interarm abundance gradients in CALIFA spiral galaxies

Spiral arms are the most singular features in disc galaxies. These structures can exhibit different patterns, namely grand design and flocculent arms, with easily distinguishable characteristics. However, their origin and the mechanisms shaping them are unclear. The overall role of spirals in the chemical evolution of disc galaxies is another unsolved question. In particular, it has not been fully explored if the H ii regions of spiral arms present different properties from those located in the interarm regions. Here we analyse the radial oxygen abundance gradient of the arm and interarm star forming regions of 63 face-on spiral galaxies using CALIFA Integral Field Spectroscopy data. We focus the analysis on three characteristic parameters of the profile: slope, zero-point, and scatter. The sample is morphologically separated into flocculent versus grand design spirals and barred versus unbarred galaxies. We find subtle but statistically significant differences betweenthe arm and interarm distributions for flocculent galaxies, suggesting that the mechanisms generating the spiral structure in these galaxies may be different to those producing grand design systems, for which no significant differences are found. We also find small differences in barred galaxies, not observed in unbarred systems, hinting that bars may affect the chemical distribution of these galaxies but not strongly enough as to be reflected in the overall abundance distribution. In light of these results, we propose bars and flocculent structure as two distinct mechanisms inducing differences in the abundance distribution between arm and interarm star forming regions

Pipe3d, a pipeline to analyze integral field spectroscopy data: II Analysis sequence and califa dataproducts

Presentamos una version mejorada de FIT3D, una herramienta de ajuste para el analisis de las poblaciones estelares y el gas ionizado en espectros de galaxias de resolucion intermedia. La misma se desarrollo para el análisis de datos de espectroscopía de campo integral y es la base de Pipe3D, un dataducto usado en el analisis de datos de los muestreos CALIFA, MaNGA y SAMI. Describimos la filosof´ıa y los pasos seguidos en el ajuste, presentando un conjunto amplio de simulaciones con el fin de estimar la precisión de los parametros derivados, mostrando el resultado de dichas simulaciones. Finalmente, comparamos el resultado del analisis con FIT3D y el obtenido mediante otros paquetes de uso frecuente, encontrando que los parametros derivados son totalmente compatibles.We present Pipe3D, an analysis pipeline based on the FIT3D fitting tool, developed to explore the properties of the stellar populations and ionized gas of integral field spectroscopy (IFS) data. Pipe3D was created to provide coherent, simple to distribute, and comparable dataproducts, independently of the origin of the data, focused on the data of the most recent IFU surveys (e.g., CALIFA, MaNGA, and SAMI), and the last generation IFS instruments (e.g., MUSE). In this article we describe the di fferent steps involved in the analysis of the data, illustrating them by showing the dataproducts derived for NGC 2916, observed by CALIFA and P-MaNGA. As a practical example of the pipeline we present the complete set of dataproducts derived for the 200 datacubes that comprises the V500 setup of the CALIFA Data Release 2 (DR2), making them freely available through the network. Finally, we explore the hypothesis that the properties of the stellar populations and ionized gas of galaxies at the e ffective radius are representative of the overall average ones, finding that this is indeed the case.Fil: Sánchez, S. F.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Pérez, E.. Instituto de Astrofísica de Andalucía; España. Consejo Superior de Investigaciones Científicas; EspañaFil: Sanchez Blazquez, P.. Departamento de Fisica Teorica ; Facultad de Ciencias ; Universidad Autonoma de Madrid;Fil: García Benito, Rubén. Instituto de Astrofísica de Andalucía; España. Consejo Superior de Investigaciones Científicas; EspañaFil: Ibarra Mede, H. J.. Space Telescope Science Institute; Estados UnidosFil: González, J. J.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Rosales Ortega, F. F.. Instituto Nacional de Astrofísica, Optica y Electrónica ; MéxicoFil: Sánchez Menguiano, L.. Instituto de Astrofísica de Andalucía; España. Consejo Superior de Investigaciones Científicas; EspañaFil: Ascasibar, Y.. Universidad Autónoma de Barcelona. Facultad de Física. Departamento Astronomía y Meteorología; EspañaFil: Bitsakis, T.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Law, D.. Space Telescope Science Institute; Estados UnidosFil: Cano Díaz, M.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: López Cobá, C.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Marino, R. A.. Universidad Complutense de Madrid; EspañaFil: Gil de Paz, A.. Australian Astronomical Observatory; AustraliaFil: López Sánchez, A.. Instituto de Astrofísica de Canarias (iac); EspañaFil: Barrera Ballesteros, Jorge K.. Instituto de Astrofísica de Canarias; EspañaFil: Galbany, Lluís. Millennium Institute Of Astrophysics; Chile. Universidad de Chile; ChileFil: Mast, Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Abril Malgarejo, V.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Roman Lopes, A.. Universidad de La Serena; Chil