GALAXIES

Author: FERNÁNDEZ BARBA DAVID.
Year: 2004.
University: BARCELONA [More theses of this university] [www.ub.es].
Place of defense: UNIVERSIDAD DE BARCELONA.
Place of preparation: UNIVERSIDAD DE BARCELONA.

Summary: This paper has done a study of the spiral structure and kinematics of the young stellar component of the Galaxy in the solar environment on three different scales, which have made it possible spiral galactic structure, the Gould Belt and the young stellar component in the closest solar environment. We have built three samples of stars with data from the Hipparcos catalog. The first of these is formed by stars of spectral types is OyB, and contains information astrométrica, photometric, radial velocities and various physical parameters of stars, including age. The second sample contains all variable stars cefeidas the Hipparcos catalog, with information astrométrica, distances calculated from two calibrations periodo-luminosidad and radial velocities. Finally, we have compiled all the information available so far in the literature concerning local youth associations that have been discovered in the solar environment closest in recent years. From samples of stars that have been built has been studied, first, the spiral structure of the Galaxy. The most outstanding results in this section are that the Sun is located in the outer part of the spiral arm closest and outside the circle of corrotación. Both results may be of great significance in the history of recent training in the solar environment. It has also obtained a negative value (and significant) for the divergence of the velocity field (a term K). The results have been validated through some simulations, which have yielded an estimate of external errors and an evaluation of the biases that affect various parameters obtained. At one scale to 1 kpc of heliocentric distance, the dominant structure in the solar environment is the so-called Gould Belt, which contains most of the young stars and clouds of dust and gas from this region. In our work we have obtained targeting parameters Belt has been studied and its peculiar kinematics, after conducting some simulations with the same objectives as those mentioned above. It has been obtained that the stars of complex Scorpio-Centaurus (Sco-Cen) presents a cinematic does not fit into the envisaged by the various models that attempt to explain the evolution of kinematic belt. It has also been obtained that the movement of expansion of this structure does not appear to be an overall effect because it is restricted to the first -250 pc heliocentric distance. Finally, the study of the integration of the orbits backwards in time of the local youth associations and members of the complex Sco-Cen has not infer that the former is not formed within this complex, but in small molecular clouds in the surrounding area, and who had previously been expelled. Moreover, it appears that some of these supernova local youth associations was probably responsible for the overheating of the Local Bubble is a few million years. Finally, taking into account the results obtained in various paragraphs of this paper, we propose an arena for training stellar recent solar environment from the impact of a large molecular cloud with the internal spiral arm, which resulted in different stages complex Sco-Cen and local youth associations.

Author: Perucho i Pla Manuel.
Year: 2004.
University: VALENCIA [More theses of this university] [www.uv.es].
Place of defense: FACULTAD DE FÍSICA.
Place of preparation: UNIVERSITAT DE VALÈNCIA ESTUDI GENERAL.

Summary: This thesis is based on the study of fluid instabilities Kelvin-Helmholtz in relativists and their applications in astrophysical jets extragalactic. The methodology used is the analytical study of the development of instabilities of small amplitude, and the implementation of a numeric code that solves the equations of the relativistic hydrodynamics for the study of the transition to non-linear regime and its evolution in the long term. It has studied the influence of physical parameters (such as temperature and velocity) relativistic fluid in its stability. It also has included a study of the effect of stratification of the velocity of the fluid in the growth and development of this type nonlinear instabilities. Finally, we have made various numerical simulations based on observations of jets extraglácticos real with the purpose of establishing a method by combining linear analysis and numerical calculations, leading to the physical parameters governing such objects. This will allow us to eventually deepen our understanding of the physics of the extragalactic jets.

Author: CRISTOBAL HORNILLOS DAVID.
Year: 2004.
University: LA LAGUNA [More theses of this university] [www.ull.es].
Place of defense: FACULTAD DE FISICA UNIVERSIDAD DE LA LAGUNA.
Place of preparation: INSTITUTO DE ASTROFISICA DE CANARIAS, UNIVERSIDAD DE LA LAGUNA.

Summary: This work is intended to calculate the stellar mass of a sample of galaxies bright blue compact (LBCGs) from photometry in optical filters and near infrared. We have also measured the masses to show stellar spiral galaxies and elliptical as a comparison. For the determination of stellar masses, we have developed a code which fits photometry synthetic modeling synthesis populations photometry multiband observed galaxies. These adjustments to divert, in addition to the stellar mass, other interesting properties of these galaxies: the time it makes a significant event occurred in stellar formation and strength of the same age and the existence of a population and its underlying stellar mass. Through simulations, we determine that, despite the different values of metallicity, dust extinction by the initial mass function and lead to solutions warped, the stellar mass recovers with uncertainties lower than a factor two. We have found that the stellar masses of the galaxies are bright blue compact around ten billion solar masses, which have suffered a recent outbreak of stellar formation that involves between 5 and 10% of the stellar mass. Comparing with the masses obtained for elliptical galaxies, stellar masses of LBCGs are, in middle, about 7 times lower. The spiral galaxies covering a wide range of masses, the rates have early stellar masses similar to those of the elliptical, while the spirals are more blue stellar masses similar to those of LBCGs.

Author: MELO MARTIN VERONICA PABLA.
Year: 2004.
University: LA LAGUNA [More theses of this university] [www.ull.es].
Place of defense: FACULTAD DE CIENCIAS FISICAS.
Place of preparation: FACULTAD FISICA.

Summary: The starbursts are events in that form over the 10e4 Msol stars to a high rate in a very small area. The end result of some starbursts is the expulsion of all material processed out of the galaxy by means of so-called supervientos galactic (SVG). This thesis explores three cases of candidates to develop SVG galaxies, M82, NGC 253 and NGC 4631. There have been the stellar superclusters (SSC) of starbursts of the three galaxies in Halfa. We conclude that only M82 is developing an SVG while in other cases the stellar outbursts are confined to the galaxy. We have also identified the SSC as the constituent elements of starbursts in galaxies and concluded that their properties are factors deerminantes to trigger supervientos galactic.

Author: GONZALEZ NUEVO GONZALEZ JOAQUIN.
Year: 2004.
University: OVIEDO [More theses of this university] [www.uniovi.es].
Place of defense: E.U. INGENIERIAS TECNICAS MIERES.
Place of preparation: FACULTAD DE CIENCIAS.

Author: CASTILLO MORALES ÁFRICA.
Year: 2004.
University: GRANADA [More theses of this university] [www.ugr.es].
Place of defense: UNIVERSIDAD DE GRANADA.
Place of preparation: UNIVERSIDAD DE GRANADA.

Summary: The galaxy clusters are formed by several compoennetes observable, hundreds of galaxies, hot gas between galaxies and clusters for some, relativistic particles and coampo magnetic. These components esmiten radiation at different wavelengths, from radio hasata X-ray The combination of the observations made in this broad range of frequencies along with theoretical models, allows us to have a better knowledge of these objects. In this thesis we present an analysis of the distributions of gas and the matería dark in a sample of ten groups of galaxies nearby (0.03 higher z increased 0.09) where the temperatures are between 4.4 and 9.4 kev. These groups of galaxies have been studied in detail through their X-ray observations from which sehan deducted physical properties global com gas mass, the total mass of wealth, the mass fraction of gas and the extension on gas . We analyzed posiblesw correlations between these properties withthe results comparing gas (expressed as the ratio between the mass fractions of gas rays r500 and 0.5 xr500) and the total mass of the cluster. The extension of gas on the extension of dark matter tends to be higher in the less massive backlog. This unit can be ralacinada with intevención processing pre-calentamiento environmental intracumular during the formation of these structures. In addition presentmos new observations in X-ray obtenidad for two morphologically different galaxy clusters, CL0939 +4713 and RBS797. We analyzed the observation of accumulation CL0939 +4713 (z = 0.41) obtained with the XMM-Newton satellite, confirming that it is a young system dynamically. This conclusion is supported for the temperature distribution found in this cluster, is distinguished a region of higher temperature between the two subcúmulos major, indicating that they are at the beginning of a process of merger. The observation enhanced with the Chandra satellite show the presence of depressions in the X-ray emission from the pile RBS797, which clearly distinguishes minimum emission near the center of the pile. Problamente, gas environment intracumular has been shifted from the regions of less toward higher X-ray emission due to the pressure of relativistic particles contained in the radio lobes. RBS797 was the first cluster of galaxies distnte in which evidence has been found of this type of interaction. The comments in the wavelength radio muestrana presence deotros components interesentes in galaxy clusters, relativistic particles and the magnetic field. These are both important components dynamically com galaxies in galaxy clusters. However, the interaction between the magnetic field intra and extra-galáctico has received little attention so far, although his interconesxión of high interest. By studying in detail the dynamic estalar and gas from the central regions (r greater 1kpc) of the spiral galaxies with an inclination internal and with some kind of acitvidad nuclear, we can determine cuánatoo cmapo magnetic has been eyectado (or falling) from the region more internal galactic disk Middle intracumular. To undertake this terea, we have used this theory in the insturmento INTEGRAL based on a system of fiber optics, in combination with the spectrograph fiber WYFFOS located in the William Herschel telescope. We utilizdo spectroscopy bidimensinal to study regions cirucmnuclesaes emission has been studied and kinematics of issuers ionized comparadndo kinematics stellar and gaseous. The detailed study of the dynamics of the central region of a galaxy is a very useful tool for studying d 8 and the fl 49th ujos gas (and therefore the magnetic field) and the stars to or from the intergalactic environment . This is important for enternder interaction between the galaxy and the cluster of galaxies to which it belongs. In galaxies studied in this thesis does not appear to exist a significant gas flow, which are conducting further observations to be analyzed with the techniques developed earlier and thus studying the interconnection of the galaxy with the medium intracumular.

Author: GARCÍA GARCÍA MIRIAM.
Year: 2005.
University: LA LAGUNA [More theses of this university] [www.ull.es].
Place of defense: FACULTAD DE FÍSICA.
Place of preparation: DEPARTAMENTO DE ASTROFISICA (FACULTAD DE FISICA) E INSTITUTO DE ASTROFISICA DE CANARIAS.

Summary: The doctoral thesis is presented that is dedicated to the study of a group of massive hot stars with the telescope Far Ultraviolet spectra spectroscopy Exlorer (FUSE, 905-1187A), supplemented by data file telescope international Ultraviolet Explor (SUI) and the Hubble Space Telescope (HST) to the rank 1150-1800A. The data have been analyzed with synthetic spectra calculated with the code WM-Basic, which produces models unified spherical symmetry of the expanding atmospheres, with a precise treatment of the effects of non-local thermodynamic equilibrium and the blockade lines. As support for the analysis we build a network models WM-Basic that, compared with the observations, we can identify the values of the parameters stellar. The network also allows us to the development of diagnostic criteria spectral. The central part of the thesis is the quantitative spectroscopic analysis of a sample of stars in the Milky Way, with spectral types O and a half early. The double-IFO 1032A, content in the range FUSE, plays a decisive role in the characterization of shocks in the wind and, in particular, the quantification of radiation that areas cooling broadcast in the ranks UV-extremo and x-rays. Our main result is the production of a new scale of temperatures for spectral subtypes covering sample O3-O7. The temperature values derived for the stars analyzed are lower than those identified in previous work in all cases, and are also lower than those Calibrations existing spectrum allocated to these types. The review of the temperature scale toward lower values has implications in many fields of as trofísica. Finally, we present the first points in the UV-lejano of stars in M31 and M33, accessible thanks to the increased sensitivity of the telescope FUSE. While it was not feasible to a quantitative analysis of the spectra, they contain important information about the winds of the stars of M31 and M33 and their mentality. The qualitative analysis of the spectral morphology in UV-lejando in these galaxies is an essential first step for future work and for the quantitative analysis of observations of distant objects without spatial resolution.

Author: ROZAS AMADOR JOSÉ MARÍA.
Year: 2005.
University: BARCELONA [More theses of this university] [www.ub.es].
Place of defense: FACULTAT DE FISICA.
Place of preparation: UNVIERSIDAD DE BARCELONA.

Summary: This thesis has mainly consisted of the implementation of the formation of the first stars (Pob.III) in a semi model of galaxy formation. This model, called AMIGA, introduced the feature to allow a study of the universe in a very broad range of time and masses of dark matter halos. Thus, the formation of the first stars and the intergalactic environment (IGM) has been able to follow so attached and autoconsistente. Utilizing these features, the present thesis work has dealt with the study of various aspects of the stars of Pob.III restricting their properties by those of the IGM at high redshift. As a result, obtained a series of typical values for the initial mass function, the mass stellar formed and the metallicity threshold to form objects Pob.III. In parallel, justify approaches undertaken so far into models semianalíticos not considered the effect of this type of object.

Author: HIDALGO RODRIGUEZ SEBASTIAN LUIS.
Year: 2005.
University: LA LAGUNA [More theses of this university] [www.ull.es].
Place of defense: FACULTAD DE FISICAS.
Place of preparation: INSTITUTO DE ASTROFISICA DE CANARIAS.

Summary: The structures of low surface brightness detected in the Local Group dwarf galaxy and its vicinity are extended structures that represent a record fssil the evolutionary past of galaxies. His composicisn stellar analysis is the object of this thesis. It had considered two galaxies of different morfologma. The first, NGC3109, a galaxy is shown in profile, it is idsnea to study stellar populations in the extended structure, avoiding the presence of stars on your disk. Defining two main focuses for the galaxy, it has been found that the scaling factors of poblacisn stellar young in both directions are compatible with a disc deproyectado. However, the scale factor of poblacisn stellar age vieja-intermedia presents a change of slope in the minor axis, which does not appear in the major axis or disk of NGC 3109. The fotometrma large field diameter, distribucisn population stellar content in gas and rotacisn we deduce that NGC3109 is a spiral galaxy of type M33. The seguna galaxy studied is Phoenix, a galaxy-type dSph / dIrr located at a distance of about 400 kpc from the Vma Láctea. This is close enough to observe the turn-offs age old using HST, but far enough to not be significantly affected by it the Vma Láctea potential. It has resolved its history Formacisn Primetime using an algorithm genitico to compare a DCM sintitico with DCM observed. From the evidence of internal consistency of IAC-pop show that the solutions that are obtained are stable and that IAC-pop applies to a observacisn real resolved, while the distribucisn age and metalicidades of the stars of a galaxy . Following evaluation of the distribucisn of stocks with stellar radius galactocintrico Phoenix, it is clear that there is a gentle gradient in the stellar populations, increasing the age of the stars evenly with the radio. Therefore, we could not find a stellar halo in Phoenix similar to the Vma Láctea. From analysis of the factors of scale in funcisn time, it has been deduced that Phoenix was more extensive at the time of his formacisn now. The result has been obtained from a parameter declined to 26.6 Ga realizes that the disminucisn of tamaqo the regions of formacisn stellar Galaxy over time. These results favor the scenario that we have called for shrinking the formacisn of dwarf galaxies, segzn which, as the gas is consumed to form stars, formacisn stellar will focus increasingly toward the center of the galaxy.

Author: PEDRAZ MARCOS SANTOS.
Year: 2005.
University: COMPLUTENSE DE MADRID [More theses of this university] [www.ucm.es].
Place of defense: FACULTAD DE CIENCIAS FÍSICAS.
Place of preparation: FACULTAD DE CIENCIAS FÍSICA.

Summary: We have studied the stellar populations of 42 galaxies dwarf elliptical (dEs) of the Virgo cluster spectroscopic observations by telescopes from 2.5my 4.2m in diameter. Analysis of the spectra have yielded kinematic parameters such as velocity dispersion and radial velocity at the center of all galaxies dwarfs the samples, as well as other 8 elliptical and 7 compact giants who have served as a reference. For the first time have been measured gradients of these parameters on a significant sample of dwarf elliptical, finding that, unlike those seen so far, not all dEs are supported by the anisotropy in the distribution of velocities. A significant fraction of them show a high speed rotation. By measuring the intensity of the absorption lines in the spectra were obtained dEs rates Lick, compared with prediciones of you synthesis models of populations, have allowed estimating the age and metallicity of the stellar populations these galaxies. The values of the indices measured in the central regions of the dEs while showing greater dispersion, are coincident with the extension of the relationship found with the dispersal of central speeds toward lower values of this for the giant elliptical. Only significant differences are (higher values) for the indices magnesium. The area occupied by these indices capitals in prediciones of synthesis models, unlike what happens to the giant elliptical, not dependent on the cash index used. Where it appears that on the abundances of elements in the stellar populations of dwarf elliptical is similar to that of the stars in the solar neighborhood, whose spectra have been developed models. As a result, ages and metalicidades obtained for dEs show less dependence on the indexes elected to the giant elliptical. On average, dwarf elliptical galaxies are significantly younger and less metal giant. While the dispersion of the values of age and metallicity respect of the measure are clearly greater than those expected from the errors in measurements. Although the dwarf elliptical do not conform to the relationship edad-metalicidad found for the Giants, if they show a similar trend, in the sense of being the younger more metal but with a greater slope. However, if coincide with the plane on which the giants are located in the space defined by age, and metallicity central velocity dispersion. The gradients rates Mg2 and Mg1 are significantly more planes in dEs that the giants. By contrast, there are differences to the other indices measured. The odds of correlation between these indices gradients and their core values increase to include in the elliptical galaxies dEs of this work, but only for the Mg2 the correlation is really significant. In interpreting changes in the indices over the radio as the dEs gradients Jan dad and metallicity is that, generally speaking the dwarf elliptical stellar populations are somewhat younger and clearly more metal in the central regions. In a larger proportion gradients are consistent with duties exclusively in metallicity variations, but there are also clear examples of gradients of age.

Author: LOPEZ SANCHEZ ANGEL RAFAEL.
Year: 2006.
University: LA LAGUNA [More theses of this university] [www.ull.es].
Place of defense: AULA MAGNA FACULTAD DE FISICA Y MATEMATICAS.
Place of preparation: INSTITUTO DE ASTROFISICA DE CANARIAS.

Summary: In this thesis we present a morphological study, photometric and spectroscopic details of a sample of 20 galaxies Wolf-Rayet (WR). The WR galaxies are a subtype of the H II galaxies whose integrated spectrum shows emission lines WR own rating, indicating the presence of a large population of massive stars and the extreme youth of the outbreak of stellar formation. The main objective is to study the formation and stellar populations Oy WR stars in these objects, as well as to understand the role they have interactions between objects fellow low surface brightness in the firing of outbreaks of stellar formation. We employ deep images with spatial resolution in optical filters and near infrared (NIR) broadband interferenciales (H alpha and continuous adjacent) to study the morphology and stellar ionized gas in each galaxy, analyzing the contents of ionizing stars, age for outbreaks and the underlying population of older stars. It has also been used spectroscopy rendija long or echelle to study the physical conditions (temperatures and densities electronic redness, nature of the ionization), the chemical abundances and kinematics of ionized gas, as well as to determine the content of massive stars and their locating space in each object. This analysis has made it possible to distinguish between the pre-existing or tidal nature of the objects found around the dwarf galaxies studied. Of particular interest is the study of clusters of galaxies HCG 31 and Mkn 1087, which required several body interactions to explain the queues, bridges, mergers and dwarf galaxies tide found. We also include the detailed analysis of the history of stellar formation and stellar populations in the galaxy IRAS 08339 +6517, where we see for the first time the trait WR and that is also interacting with an object nearby dwarf independent. However, one of the major achievements of this thesis is the detection of weak lines II recombination of O and C in our profound VLT spectra of the dwarf galaxy NGC 5253, found for the first time in a starburst. In addition, we found a localized enrichment of nitrogen and helium that is consistent with the expected by contamination of WR stars detected. We completed our observations in the optical and NIR data on X-ray, far infrared (FIR) and radio (HIy continuous) extracted from the literature to obtain a more complete picture of the stellar formation and evolution of each object. Finally, we present some general results of the entire sample of galaxies, looking for relationships between quantities photometric, spectroscopic and those found in other wavelengths. We conclude that the vast majority of the galaxies studied (16 of 20, ~ 80% of the systems studied) show traces of interaction, (and cinematic disturbed morphologies, differences in abundances, loss of neutral gas, etc.), confirming the hypothesis that the interactions between objects or dwarves is the primary mechanism that triggers the formation of galaxies in stellar type Wolf-Rayet.

Author: ROMERO GOMEZ MERCE.
Year: 2006.
University: POLITÉCNICA DE CATALUÑA [More theses of this university] [www.upc.edu].
Place of defense: UNIVERSITAT POLITÈCNICA DE CATALUNYA.
Place of preparation: EPSC, EDIFICI C1 Campus BAIX LLOBREGAT.

Author: CASTRO RODRIGUEZ NIEVES D..
Year: 2006.
University: LA LAGUNA [More theses of this university] [www.ull.es].
Place of defense: INSTITUTO DE ASTROFISICA DE CANARIAS.
Place of preparation: DEPARTAMENTO DE ASTROFISICA E INSTITUTO DE ASTROFISICA DE CANARIAS.

Summary: In this paper we studied the diffused light in clusters and clusters of galaxies. The diffused light is made up of stars divorced from the cluster of galaxies and move under the action of potential global wealth. This component cúmular corresponds to a 5-15% of the total mass of the cluster. It was discovered for the first time in the accumulation of Coma by Zwicki in 1951 that found a contribution to the total luminosity of that wealth came from the area between galaxies. In past decades the study of this component has a number of problems, the most important being its low surface brightness. In this paper we used the Planetary Nebulae (PN) as a tracer of this component of the medium intracumular (or intra). By detecting the PN can infer the amount of diffused light that we are going to take each of the zones. In this paper we studied the proportion of diffused light in several clusters of galaxies (Leo and HCG44) and the Virgo cluster, as well as developed a robust method for the detection and classification of the PN. We have concluded that the diffused light this correlada with the amount of E SO galaxies in compact groups of galaxies, and the origin of that light will be related to the formation of the elliptical galaxies in the clusters of galaxies. Likewise, for the Virgo cluster, we have obtained that the contribution of diffused light correlates with the position of giant galaxies in the Virgo, so concluímos that component cumular had formed through the processes that have led to big E galaxies in the Virgo. In addition, this component is very young, as they form structures inomogéneas that had already been diluted from being created in times of the early accumulation.

Author: ELICHE MORAL MARIA DEL CARMEN.
Year: 2006.
University: LA LAGUNA [More theses of this university] [www.ull.es].
Place of defense: FACULTAD DE FISICA DE LA UNIVERSIDAD DE LA LAGUNA.
Place of preparation: INSTITUTO DE ASTROFISICA DE CANARIAS.

Summary: Both comments as cosmological simulations indicate that the mergers of galaxies processes are quite common in the universe. But still unknown relevance of mergers in the galactic evolution and the formation of the current bulbs over other possible formation processes. The basic objective of this thesis is to study the role of mergers in the emergence of the type of early galactic population, as in the evolution of galactic bulbs, both observational and computational. We analyzed the significance of the pace of merger by studying the accounts differentials galaxies in UyB obtained on a field of ~ 900 arcmin ^ 2 probe GOYA covering strip Groth-Westphal. The magnitude limits have reached matched U = 24.8 mag and B = 25.5 mag in the system of Vega (at 50% detection efficiency for point sources). Introducing model that accounts for the first time reproduced simultaneously accounts observational in UyB in a range of 15 sizes and the Ks in a range of 10 sizes, using only measured parameters observacionalmente and without introducing alien populations of unknown origin, nor different rhythms of merger for each band. Only by imposing a redshift training for the relatively recent elliptical galaxies (zf ~ 1.5), we can reproduce the change of the slope is found in the accounts infrared Ks = 17.5 mag. A moderate optical depth galactic for all types (including early galaxies) assures us that the accounts UyB there is no sudden increase associated with the recent formation that has been imposed on the elliptical. Our models explaining the origin and evolution of galaxies weak blue until z ~ 1.5-2, from the natural evolution of the local mix, which is induced by the formation inherent in a hierarchical universe LambdaCDM. We have also studied the influence of mergers in the growth of the central structure of galaxies, through simulations not colisionales of N-cuerpos from increases on satellite galaxies disk. To ensure that the density ratios between the main and satellite galaxy in each experiment (critical in the final outcome of the merger) are realistic, we have employed a scaling based on the observational relationship of Tully-Fisher (M ~ V_ rot ^ alpha_TF ). The remnants of experiments accretion show a clear structure bulbo-disco with normal rotation curves. The reason bulbo-disco as the index n Sérsic grow as a result of the increase in all models, showing moderate values at the end of the simulation (n = 1.0-1.9). The bulb grows regardless of whether the satellite, which was completely destroyed in all experiments, reaches the center of the remnant (cases alphaTF = 3.5 or 4) or not (cases alphaTF = 3 and reasons masses bright 1:6) . The overall structural parameters evolve in a systematic way following similar trends to those comments. The dominant mechanism in the growth of the bulb is the flow toward the center of material from primary disk during the decay of the satellite. Our models are the first to confirm that the growth of bulbs from the disk material, one of the central ingredients of the secular evolution models, can be induced from outside the galaxy increases through satellite.

Author: CARRERA JIMENEZ RICARDO J..
Year: 2006.
University: LA LAGUNA [More theses of this university] [www.ull.es].
Place of defense: FACULTAD DE CIENCIAS FÍSICA.
Place of preparation: FACULTAD DE FISICA.

Summary: Â How are galaxies?, Â How evolve?. These are fundamental questions that mapped deep galaxies at high redshift address. A second approach is to reconstruct the history of the stellar formation through their stellar populations resolved. The History of stellar formation of a galaxy can be characterized by four features: the stellar formation rate, the law of chemical enrichment, the initial mass function and the fraction of binary. The differences between the different stories of stellar formation observed are determined largely by the rate of stellar formation and chemical enrichment of the law. The first of these is obtained from diagrams color-magnitud, while the law of chemical enrichment has been characterized from the color distribution of stars in the Red Giant Branch, despite the difficulty of degeneration edad-metalicidad present in it. The main objective of this work is to break this degeneracy, gaining metallicity by an alternative method. The most accurate way to measure chemical abundances are high-resolution spectroscopy. However, this technique requires an inordinate time telescope. The alternative is the low-resolution spectroscopy, which along with the modern espectroscopios multiobjeto, reveals a large number of stars in a reasonable time. In galaxies, we can only observe espectroscópicamente the brightest stars, which in many cases are the stars Giants Rojas. The appropriate index to measure the metallicity of these stars is the hat-trick of infrared Call, which is the most important feature in the infrared part of its spectrum. The relationship between the width equivalent lines triplete Call and metallicity has been studied mainly in older systems and poor in metals. However, the galaxies presented, in general, broad ranges of ages and metalicidades. The first objective of this work was to study the behavior of lines triplete Call stars open and globular clusters covering wider range of age and metallicity, 0.25 lower (Age / Ga) lower 13 and -2.2 lower [Fe / H] lesser + 0.47, which has investigated the behavior of lines Call hat trick so far. The next step has been to use this index to measure abundances stellar pair in the Magellanic Clouds and thus studying their chemical evolution. By their proximity, these galaxies are an excellent laboratory for testing the power of this method. They are easily observable from the ground and had stellar populations with a wide range of age and metallicity stars we have seen in different positions of the two galaxies. The main result is that while the Great Cloud has a metallicity similar to a radius of 6 degrees, decreasing to regions outside the Little Cloud presents a gradient of populations, in the sense that the stars are also more metallic younger , and are concentrated mainly in the central regions. On average the Large Magellanic Cloud is more metallic Small Cloud. In the case of Little Cloud, we found that older stellar populations of 1 Ga no irregular appearance now being witnessed in this galaxy.