Validation of the data received from the Gaia satellite

Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Any: 2015, Tutor: Jordi TorraThe main goal is to develop efficient tools to help validating the data received daily from the Gaia satellite. In order to do so, we study the main data processes and their outputs and build three different tools called ExtendedStats, FlIdtValidation and AutoAlarms

Formation and evolution of globular clusters in a cosmological context

Stellar clusters are observed in a variety of galactic environments, from their current formation sites like the disks of the Antennae galaxies to the old globular cluster populations which in the Milky Way mostly reside in the halo. This suggests that the evolution of these puzzling objects may be linked to that of their host galaxy. This thesis explores the formation and evolution of stellar clusters in a cosmological context. For that, analytical models are developed to describe the role of the galactic environment in shaping their demographics. A suite of cosmological, hydrodynamical simulations of Milky Way-mass galaxies from the E-MOSAICS project are used to study when stellar clusters form and how they evolve over cosmic history. These simulations are also employed to estimate the contribution of stellar clusters to the build-up of stellar haloes. Finally, the EMP-Pathfinder simulations are presented, which represent the next generation of simulations of the co-formation and evolution of stellar clusters alongside their host galaxies in a cold, dense cosmic environment. The conclusion drawn from these studies is that stellar clusters are tightly linked to their host cosmic environments. This leads to exciting new future directions that are briefly discussed

Can the Tremaine - Weinberg method be used to determine the pattern speed of the bar and the spiral arms of the Milky Way?

Màster Oficial d'Astrofísica, Física de Partícules i Cosmologia, Facultat de Física, Universitat de Barcelona, Curs: 2015-2016, Tutors: Francesca Figueras, Teresa Antoja, Mercè Romero-Gómez, Santi Roca-FàbregaThe pattern speed of the non-axisymmetric structures of the galactic disc is a key parameter to understand the dynamics in the MilkyWay. For neither the Galactic bar nor the spiral arms it is well determined. All previous determinations have large uncertainties associated avoiding to shed some light on the nature of these structures

JWST Photometry of Globular Cluster Populations in Abell 2744 at z=0.3z=0.3

JWST imaging of the rich galaxy cluster Abell 2744 at $z=0.308$ has been used by the UNCOVER team (Bezanson et al. 2022) to construct mosaic images in the NIRCAM filters. The exceptionally deep images in the ($F115W$, $F150W$, $F200W$) bands reveal a large population of unresolved pointlike sources across the field, the vast majority of which are globular clusters (GCs). To the limits of our photometry, more than 10,000 such objects were measured, most of which are in the halos of the five largest A2744 galaxies but which also include GCs around some satellite galaxies and throughout the IntraCluster Medium. Their luminosity function follows a lognormal shape, with the data reaching to within one magnitude of the classic GCLF turnover point. The colour index ($F115W-F200W$) in particular covers a range of $0.5$ mag, clearly resolving the expected internal spread of GC metallicities. The estimated GC masses are systematically higher than in present-day galaxies, consistent with a large, normal GC population seen at a $3.5~$Gyr earlier stage of dynamical evolution. Lastly, the spatial distribution of the bluer (more metal-poor) GCs resembles the gravitational lensing map of the cluster, consistent with recent theoretical suggestions.Comment: 13 pages and 13 figures. Accepted by MNRAS (September 18th 2023

El lugar de la metáfora en la teoría de los actos de habla: Searle

Nos parece sumamente difícil solucionar el problema de los usos no-literales/figurados del lenguaje desde un ámbito meramente semántico. De hecho el mismo enunciado puede ser interpretado de forma literal, metafórica o irónica, dependiendo del contexto de uso. Creemos que la teoría searliana,( la metáfora es un ejemplo de cómo divergen el significado del hablante y el significado oracional o léxico), supone un punto de partida imprescindible para los posteriores estudios pragmáticos

Inteligencia general y conducta delictiva en adolescentes sentenciados por delito de homicidio

Este estudio tiene como objeto principal determinar la relación entre la inteligencia general y la conducta delictiva, en una muestra integrada por 26 adolescentes sentenciados penalmente por el delito de homicidio, en el año 2016, que cumplen sentencia que van desde los 2 ½ años hasta los 12 años de privación de libertad, bajo la supervisión del Juzgado de Cumplimiento, de la Jurisdicción de Niñez y Adolescencia de la República de Panamá. El diseño metodológico investigativo, es de tipo correlacional de corte trasversal, se ha estudiado en un solo momento y lugar. Para la recolección de datos se examinaron 26 expedientes judiciales sobre el delito de homicidio en diversas modalidades; los puntajes de inteligencia general se lograron mediante el Test de Matrices Progresivas de Raven, forma general y para los puntajes de conducta delictiva, se utilizó la Escala Conducta Delictiva del Cuestionario de conducta Antisocial y Delictiva. Los resultados obtenidos sugieren que existe una relación entre la inteligencia y la conducta delictiva. También se identificaron una serie de factores psicológicos y sociales presentes en los adolescentes, tales como disfuncionalidad familiar, ausencia de figura paterna en la crianza de los hijos, bajos niveles educativos, problemas socioeconómicos (pobreza, desempleo), abandono o deserción del sistema educativo en el nivel primario, residencia en comunidades de alta incidencia delictiva, exposición a experiencias de violencia, alcoholismo, consumo de drogas licitas e ilícitas con inicio desde los 10 a 12 años de edad, disponibilidad de armas de fuego, pertenencia a pandillas o interaccionar con otros delincuentes. Los motivos para la ejecución de actos homicidas son principalmente la obtención de dinero fácil (robo), actos de venganza, rencillas o rivalidad entre pandillas

Galactic properties that favour star cluster formation: a statistical view

The presence or absence of star clusters in galaxies, and the properties of star cluster populations compared to their host galaxy properties, are important observables for validating models of cluster formation, galaxy formation, and galaxy assembly. In this work, we apply a Bayesian approach to fit two models to data from surveys of young clusters in star forming galaxies. The first model is a logistic regression, which allows us to include galaxies which do not have any young clusters. The second model is a hurdle model, which includes galaxies with zero clusters and also incorporates information about the total mass in the cluster system. We investigate two predictors (star formation rate and total stellar mass in the galaxy) and look at clusters younger than 10 or 100 Myr. We find that in all cases, star formation rate is the better predictor for both the probability of hosting clusters and the total mass in the cluster system. We compare our results to similar models for old globular clusters, and conclude that star cluster formation was more abundant and more efficient at higher redshifts, likely because of the high gas content of galaxies at that time.Comment: 10 pages, 5 figures, accepted by MNRA