Automatic selection of new Hα emission-line galaxies using MAMA

A full set of algorithms for the automatic analysis of low-resolution objective-prism spectra has been developed with the aim of finding new emission-line galaxies (ELGs) candidates from the Universidad Complutense de Madrid (UCM) survey prism plates. An objective-prism plate and a direct plate, used for pairing objects and to perform star-galaxy separation, have been scanned with the MAMA machine. The plates were taken in the red region of the spectrum, using the Hα+[NII] blend in emission as selection criterion. The procedure, applied to digitized spectra, is able to automatically select ELGs candidates. Density to intensity transformation has not been used in our method; the detection of the emission is performed applying three independent criteria over the one-dimensional spectra in raw data. The automatically selected sample is compared with that obtained after a careful visual scan. Spectroscopic observations at moderate spectral resolution are presented for the whole sample of candidates in order to study the drawbacks and the biases of both methods

Evaluación de un sistema de procesamiento del lenguaje natural de la banca

Actualmente existe mucha información referente en este caso al dominio de la banca. Por ello es necesario analizar como presentan la información a sus clientes, es decir, saber cómo está estructurada para poder organizarla correctamente, permitiendo a los usuarios realizar búsquedas posteriores más rápidas y eficaces. Debido al hecho de que esta información se crea con una alta frecuencia es necesario analizar cómo se presenta la información a los usuarios. A nivel de la estructura y con la ayuda de gráficos de algunos de los resultados que se pueden encontrar son: grupos de palabras que se utilizan (para determinar si proceden de un vocabulario específico), categorías gramaticales más comunes, palabras más repetidas en un dominio, los patrones encontrados, la frecuencia de los patrones encontrados. Este proyecto ha sido creado ayudar aquellas personas que se dedican a redactar la información que se muestra a los usuarios en las distintas páginas web de los bancos. Para el estudio se han obtenido más de doscientos archivos procedentes de diferentes bancos en formato pdf. Con la herramienta llamada Boilerplates; proporcionada para este proyecto creada por Eugenio Parra y reutilizada por el Grupo de Conocimiento de la Universidad en distintos proyectos. Se procesarán los documentos obtenidos permitiéndonos evaluar el sistema de procesamiento del lenguaje, estableciéndose patrones básicos y la frecuencia con las que aparecen las palabras basándonos en categorías gramaticales y la semántica financiera. Una vez obtenidos los patrones, analizaremos los resultados y podremos conocer aquellos patrones más comunes en banca y podremos facilitar a los clientes de los bancos y usuarios en general las búsquedas que realicen al tener una información organizada de la mejor forma posible.Ingeniería Técnica en Informática de Gestió

An automatic approach for selecting new Hα emission-line galaxies

The most unambiguous way to discover new emission-line galaxies (ELGs) is directly by the presence of their lines, using objective-prism plates of adequate resolution. The first survey using this technique was developed by Smith in 1975 with the 0.6 m CTIO Curtis Schmidt Telescope. The Universidad Complutense de Madrid (UCM) is carrying out a survey of ELGs with the Schmidt Telescope at Calar Alto (Almería, Spain) using the presence of Ha in emission in IIIa-F prism plates as selection criterion. The observational procedure and results are described in Rego et al. 1989; Zamorano et al. 1990; Zamorano et al. 1993. The standard procedure is to scan the plates by eye, with a low-power binocular microscope. The use of different subjective criteria in the visual inspection can produce biased samples. Moreover, the visual scan does not produce any quantitative measure but only a sample of candidates. Therefore, in order to obtain an observer-independent sample and to extract the largest amount of information from the original plates, 2 plates have been scanned with the MAMA machine 1 (Guibert & Moreau 1991; Moreau 1992) with the aim of developing an automatic procedure to detect ELGs spectra

Observations of a complete sample of Hα emission-line galaxies. Long-slit spectroscopy of galaxies in UCM lists 1 and 2

Spectroscopic observations for the full sample of Her emission-line galaxy candidates (ELGs) from the Universidad Complutense de Madrid objective-prism survey Lists 1 and 2 have been obtained in order to investigate fully the properties of the survey constituents as well as the selection characteristics and completeness limits of the survey itself. The spectroscopic data include redshifts, line fluxes, equivalent widths, emission-line ratios, optical reddening estimates and synthesized color indexes. We find that 74% of the objects in this sample do exhibit emission Lines. We compare our observational data, with parameters given in the published survey lists in order to assess the usefulness of the latter. The different emission-line galaxies have been classified according to their spectra in several groups. Gray-scale images of the CCD spectra near the main emission lines, spatial profiles at the continuum and the Line for [OIII] λ5007 and Hα lines, as well as plots of the coadded spectra of selected galaxies are presented, and a number of peculiar objects are described

Anisotropic lattice changes in femtosecond laser inscribed Nd3+:MgO:LiNbO3 optical waveguides

We report on the fabrication and microspectroscopy imaging of femtosecond laser written double-filament based Nd3+ :MgO:LiNbO3 optical waveguides. The waveguiding high refractive-index regions are identified by blueshifts of the Nd3+ ion fluorescence lines with no deterioration in the fluorescence efficiency, whereas filamentary low-index regions are identified by both a Nd3+ line redshift and a fluorescence efficiency reduction. The lattice structural micromodifications at the origin of both waveguide formation and Nd3+ fluorescence changes have been investigated by means of confocal micro-Raman experiments. We have found that the direct laser written filaments are mainly constituted by a large density of defects, together with a marked axial compression perpendicular to the filaments �along the optical c-axis�. Conversely, the high-index waveguiding regions are characterized by a pronounced anisotropic dilatation of the LiNbO3 lattice xy-planes

Quantum spin fluctuations in the dipolar Heisenberg-like rare earth pyrochlores

The magnetic pyrochlore oxide materials of general chemical formula R2Ti2O7 and R2Sn2O7 (R = rare earth) display a host of interesting physical behaviours depending on the flavour of rare earth ion. These properties depend on the value of the total magnetic moment, the crystal field interactions at each rare earth site and the complex interplay between magnetic exchange and long-range dipole-dipole interactions. This work focuses on the low temperature physics of the dipolar isotropic frustrated antiferromagnetic pyrochlore materials. Candidate magnetic ground states are numerically determined at zero temperature and the role of quantum spin fluctuations around these states are studied using a Holstein-Primakoff spin wave expansion to order 1/S. The results indicate the strong stability of the proposed classical ground states against quantum fluctuations. The inclusion of long range dipole interactions causes a restoration of symmetry and a suppression of the observed anisotropy gap leading to an increase in quantum fluctuations in the ground state when compared to a model with truncated dipole interactions. The system retains most of its classical character and there is little deviation from the fully ordered moment at zero temperature.Comment: Latex2e, 18 pages, 4 figures, IOP forma

Paleomagnetism from Deception Island (South Shetlands archipelago, Antarctica), new insights into the interpretation of the volcanic evolution using a geomagnetic model

Deception Island shows the most recent exposed active volcanism in the northern boundary of the Bransfield Trough. The succession of the volcanic sequence in the island is broadly divided into pre- and post-caldera collapse units although a well-constrained chronological identification of the well-defined successive volcanic episodes is still needed. A new paleomagnetic investigation was carried out on 157 samples grouped in 20 sites from the volcanic deposits of Deception Island (South Shetlands archipelago, Antarctic Peninsula region) distributed in: (1) volcanic breccia (3 sites) and lavas (2 sites) prior to the caldera collapse; (2) lavas emplaced after the caldera collapse (10 sites); and (3) dikes cutting pre- and the lower- most post-caldera collapse units (5 sites). The information revealed by paleomagnetism provides new data about the evolution of the multi-episodic volcanic edifice of this Quaternary volcano, suggesting that the present-day position of the volcanic materials is close to their original emplace- ment position. The new data have been combined with previous paleomagnetic results in order to tentatively propose an age when comparing the paleomagnetic data with a global geomagnetic model. Despite the uncertainties in the use of averaged paleomagnetic data per volcanic units, the new data in combination with tephra occurrences noted elsewhere in the region suggest that the pre-caldera units (F1 and F2) erupted before 12,000 year BC, the caldera collapse took place at about 8300 year BC, and post-cal- dera units S1 and S2 are younger than 2000 year BC

Difusió virtual d'itineraris de camp en ciències de la terra

El portal d'internet GEOCAMP (http://einstein.uab.es/_c_gr_geocamp/geocamp/), d'activitats de camp en Ciències de la Terra permet optimitzar el treball abans, després i durant una excursió. Fins ara aquest ha estat el contingut del recurs virtual. La gran acceptació que ha anat tenint entre els alumnes de la universitat (sobretot dels primers cursos) com en altres entorns (professorat de secundària etc.) ens ha portat a ampliar-ne el seu abast. Així doncs, ens hem plantejat dos objectius. Un primer objectiu ha estat la traducció de la web al castellà i l'anglès. Un segon objectiu ha estat desenvolupar un apartat de propostes d'itineraris de camp concrets. Aquest segon objectiu ha de contribuir a omplir de contingut el recurs web a partir de l'aportació d'itineraris que estem desenvolupant des de dins el projecte però també a partir d'aportacions externes