The Spitzer Atlas of Stellar Spectra

We present the Spitzer Atlas of Stellar Spectra (SASS), which includes 159 stellar spectra (5 to 32 mic; R~100) taken with the Infrared Spectrograph on the Spitzer Space Telescope. This Atlas gathers representative spectra of a broad section of the Hertzsprung-Russell diagram, intended to serve as a general stellar spectral reference in the mid-infrared. It includes stars from all luminosity classes, as well as Wolf-Rayet (WR) objects. Furthermore, it includes some objects of intrinsic interest, like blue stragglers and certain pulsating variables. All the spectra have been uniformly reduced, and all are available online. For dwarfs and giants, the spectra of early-type objects are relatively featureless, dominated by Hydrogen lines around A spectral types. Besides these, the most noticeable photospheric features correspond to water vapor and silicon monoxide in late-type objects and methane and ammonia features at the latest spectral types. Most supergiant spectra in the Atlas present evidence of circumstellar gas. The sample includes five M supergiant spectra, which show strong dust excesses and in some cases PAH features. Sequences of WR stars present the well-known pattern of lines of HeI and HeII, as well as forbidden lines of ionized metals. The characteristic flat-top shape of the [Ne III] line is evident even at these low spectral resolutions. Several Luminous Blue Variables and other transition stars are present in the Atlas and show very diverse spectra, dominated by circumstellar gas and dust features. We show that the [8]-[24] Spitzer colors (IRAC and MIPS) are poor predictors of spectral type for most luminosity classes.Comment: Accepted by ApJS; Atlas contents available from: http://web.ipac.caltech.edu/staff/ardila/Atlas/index.html; http://irsa.ipac.caltech.edu/data/SPITZER/SASS/; 70 PDF pages, including figure

Herschel Observations of Debris Disks from WISE

The \Vide Field Infrared Survey Explorer (WISE) has just completed a sensitive all-sky survey in photometric bands at 3.4, 4.6,12 and 22 microns. We report on a study of main sequence Hipparcos and Tycho catalog stars within 120 pc with WISE 22 micron emission in excess of photospheric levels. This warm excess emission traces material in the circumstellar region likely to host terrestrial planets and is preferentially found in young systems with ages < 1 Gyr. Nearly a hundred of the WISE new warm debris disk candidates detected among FGK stars are being observed by Herschel/PACS to characterize circumstellar dust. Preliminary results indicate 70 micron detection rates in excess of 80% for these targets, suggesting that most of these systems have both warm and cool dust in analogy to our asteroid and Kuiper belts. In this contribution, we will discuss the WISE debris disk survey and latest results from Herschel observations of these sources

Configuración Software de la directividad de arrays lineales

A line array can be defined as a column of loudspeakers that is designed so that these work together to achieve a higher directivity. This paper presents an application that enables a user to rotate the wavefront of uniform line arrays. Theoretical background and details of the implementation are provided. The validity of the application is tested with measurements of the directivity that are also compared with simulations.Este trabajo ha sido financiado Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech y el grupo de investigación Aplicación de las Tecnologías de la Información y Comunicaciones (PAI TIC-208)

Hacia el análisis de oportunidades energéticas con fuentes alternativas en el departamento de Nariño

Los proyectos sostenibles con fuentes no convencionales de energía han probado ser una solución técnica y económicamente factible para la energización de las regiones apartadas. Partiendo de la situación generalizada del país y, en particular de Nariño, el planteamiento de proyectos de investigación que analicen los recursos locales permitirá contribuir al desarrollo de un modelo que tenga en cuenta la inclusión de fuentes renovables y su gestión por medio de tecnologías de redes inteligentes que faciliten programas de eficiencia energética y uso racional de la energía. En este sentido, el proyecto Análisis de Oportunidades Energéticas con Fuentes Alternativas en el departamento de Nariño (ALTERNAR) plantea la caracterización de los recursos a nivel local y la investigación en sistemas completos de suministro de energía en zonas no interconectadas para incentivar el desarrollo económico y social de estas regiones rurales del departamento

EVALUACIÓN DEL NICHO ECOLÓGICO EN UN GREMIO DE CARNÍVOROS DEL PARQUE NATURAL SIERRA NANCHITITLA, MÉXICO

La evaluación de las relaciones entre depredadores, sus presas, el ambiente y los recursos usados es importante para entender los mecanismos que influyen en la estructura de la comunidad. Es común realizar éstos análisis congregando especies dentro de grupos que explotan el mismo tipo de recursos de forma similar, conocidos como gremios. De esta manera, los organismos sobreviven a través del tiempo tanto como puedan competir exitosamente por recursos y lleven a cabo estrategias de repartición. De acuerdo a la estrategia de repartición de recursos entre especies para coexistir y al tamaño corporal como un factor importante en el uso de recursos, en este estudio se prueba la hipótesis de que existirá una mayor sobreposición de los recursos utilizados, entre especies de tamaño y hábitos similares, manteniendo 3 subgrupos: depredadores tope (Puma concolor y Panthera onca), mesodepredadores carnívoros (Leopardus pardalis, Leopardus wiedii y Puma yagouaroundi) y mesodepredadores omnívoros (Nasua narica y Urocyon cinereoargenteus). En este estudio, se analizaron las tres dimensiones del nicho ecológico (trófica, espacial y temporal), para lo cual, se colectaron excrementos de manera oportuna a lo largo de diferentes trayectos (30 km), y fueron identificados a través de perfiles de ácidos biliares. Se ubicaron trampas cámara para registrar la actividad de las especies y determinar su asociación con diferentes eco-variables (vegetación, pendiente, distancia a ríos, caminos, poblados etc.) que explican el hábitat usado. Los resultados demuestran la existencia de tres grupos de depredadores. Lo cual indica una repartición estratégica de los recursos usados que disminuye la competencia y favorece la coexistencia de estos depredadores. El análisis en conjunto de las dimensiones del nicho permite obtener una evaluación más completa del nicho ecológico, más aún cuando se aborda a nivel de gremios

Observations of 51 Ophiuchi with MIDI at the VLTI

We present interferometric observations of the Be star 51 Ophiuchi. These observations were obtained during the science demonstration phase of the MIDI instrument at the Very Large Telescope Interferometer (VLTI). Using MIDI, a Michelson 2 beam combiner that operates at the N band (8 to 13 microns), we obtained for the first time observations of 51 Oph in the mid-infrared at high-angular resolution. It is currently known that this object presents a circumstellar dust and gas disk that shows a very different composition from other Herbig Ae disks. The nature of the 51 Oph system is still a mystery to be solved. Does it have a companion? Is it a protoplanetary system? We still don't know. Observations with MIDI at the VLTI allowed us to reach high-angular resolution (20 mas).We have several uv points that allowed us to constrain the disk model. We have modeled 51 Oph visibilities and were able to constrain the size and geometry of the 51 Oph circumstellar disk.Comment: 5 pages, 3 figures, 2 tables, to be published in the proceedings of "The Power of Optical / IR Interferometry: Recent Scientific Results and 2nd Generation VLTI Instrumentation", Garching, April 4-8, 200

Observations of Ultraluminous Infrared Galaxies with the Infrared Spectrograph on the Spitzer Space Telescope: Early Results on Mrk 1014, Mrk 463, and UGC 5101

We present spectra taken with the Infrared Spectrograph on Spitzer covering the 5-38micron region of three Ultraluminous Infrared Galaxies (ULIRGs): Mrk 1014 (z=0.163), and Mrk 463 (z=0.051), and UGC 5101 (z=0.039). The continua of UGC 5101 and Mrk 463 show strong silicate absorption suggesting significant optical depths to the nuclei at 10microns. UGC 5101 also shows the clear presence of water ice in absorption. PAH emission features are seen in both Mrk 1014 and UGC 5101, including the 16.4micron line in UGC 5101. The fine structure lines are consistent with dominant AGN power sources in both Mrk 1014 and Mrk 463. In UGC 5101 we detect the [NeV] 14.3micron emission line providing the first direct evidence for a buried AGN in the mid-infrared. The detection of the 9.66micron and 17.03micron H$_{2}$ emission lines in both UGC 5101 and Mrk 463 suggest that the warm molecular gas accounts for 22% and 48% of the total molecular gas masses in these galaxies.Comment: Accepted in ApJ Sup. Spitzer Special Issue, 4 pages, 3 figure

Variáveis agronômicas e variabilidade viral entre videiras sintomáticas e assintomáticas para viroses.

Os objetivos deste trabalho foram avaliar variáveis agronômicas em videiras com e sem sintomas de virose e caracterizar isolados virais destas plantas