Relevant bibliographies by topics / Galaxies: abundance / Dissertations / Theses
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Dissertations / Theses on the topic 'Galaxies: abundance'

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Published: 1 April 2023

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1

Hempel, Angela. "Classification and abundance of extremely red galaxies with R-J]= 5." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=973946733.

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2

SAMUROVIC, SRDJAN. "DARK MATTER IN EARLY-TYPE GALAXIES WITH X-RAY HALOES. A SPECTROSCOPIC STUDY OF DYNAMICS AND ABUNDANCE INDICES." Doctoral thesis, Università degli studi di Trieste, 2004. http://thesis2.sba.units.it/store/handle/item/12724.

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3

Sakr, Ziad. "Cosmology beyond ΛCDM model in the light of cluster abundance tension". Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30346.

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Le modèle ΛCDM permet de décrire avec une grande précision la plupart des présentes observations cosmologiques. Cependant, l'un de ses paramètres, σ 8, mesurant l'amplitude de fluctuations de la matière, présente une discordance entre sa valeur contrainte par le spectre de puissance angulaire du CMB de la mission Planck, les Cls, et celle déterminée à partir des amas SZ dans l'univers proche. Dans le présent travail on explore divers extensions du modèle ΛCDM comme origines possibles de cette anomalie. Pour tester les effets de ces extensions, nous avons effectué une analyse Monte Carlo on l'o
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Diaz, Beltran A. I. "Chemical abundances in spiral galaxies." Thesis, University of Sussex, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.372064.

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Guo, Yicheng, David C. Koo, Yu Lu, et al. "STELLAR MASS–GAS-PHASE METALLICITY RELATION AT 0.5 ≤ z ≤ 0.7: A POWER LAW WITH INCREASING SCATTER TOWARD THE LOW-MASS REGIME." IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/621237.

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We present the stellar mass (M-*)-gas-phase metallicity relation (MZR) and its scatter at intermediate redshifts (0.5 <= z <= 0.7) for 1381 field galaxies collected from deep spectroscopic surveys. The star formation rate (SFR) and color at a given M-* of this magnitude-limited (R less than or similar to 24 AB) sample are representative of normal star-forming galaxies. For masses below 10(9) M-circle dot, our sample of 237 galaxies is similar to 10 times larger than those in previous studies beyond the local universe. This huge gain in sample size enables superior constraints on the MZR and it
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Lipman, Keith. "Chemical abundances of primeval galaxies from QSO absorption lines." Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363292.

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7

Van, der Swaelmen Mathieu. "Évolution chimique du Grand Nuage de Magellan." Phd thesis, Université Nice Sophia Antipolis, 2013. http://tel.archives-ouvertes.fr/tel-00833887.

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Malgré des années de travaux théoriques et observationnels intensifs, nous sommes toujours loin d'une complète compréhension de l'univers proche, la Voie Lactée (MW) et ses galaxies voisines. Parmi les satellites de la MW, le Petit et le Grand Nuage de Magellan (LMC) sont particulièrement intéressants puisqu'ils forment le plus proche exemple de galaxies en interaction gravitationnelle et hydrodynamique, et partant, constituent un laboratoire unique pour étudier les effets des marées et l'échange de matière sur l'évolution chimique et l'histoire de la formation stellaire d'une galaxie. Le LMC
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Jeon, Myoungwon, Gurtina Besla, and Volker Bromm. "Connecting the First Galaxies with Ultrafaint Dwarfs in the Local Group: Chemical Signatures of Population III Stars." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/627108.

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We investigate the star formation history (SFH) and chemical evolution of isolated analogs of Local Group (LG) ultrafaint dwarf galaxies (UFDs; stellar mass range of 10(2)M(circle dot) < M-*< 10(5) M-circle dot) and gas-rich, low-mass dwarfs (Leo P analogs; stellar mass range of 10(5)M(circle dot) < M-*< 10(6) M-circle dot). We perform a suite of cosmological hydrodynamic zoom-in simulations to follow their evolution from the era of the first generation of stars down to z=0. We confirm that reionization, combined with supernova (SN) feedback, is primarily responsible for the truncated star for
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9

Spencer, Meghin E., Mario Mateo, Matthew G. Walker, and Edward W. Olszewski. "A Multi-epoch Kinematic Study of the Remote Dwarf Spheroidal Galaxy Leo II." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/623237.

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We conducted a large spectroscopic survey of 336 red giants in the direction of the Leo II dwarf galaxy using Hectochelle on the Multiple Mirror Telescope, and we conclude that 175 of them are members based on their radial velocities and surface gravities. Of this set, 40 stars have never before been observed spectroscopically. The systemic velocity of the dwarf is 78.3 +/- 0.6 km s(-1) with a velocity dispersion of 7.4 +/- 0.4 km s(-1). We identify one star beyond the tidal radius of Leo II but find no signatures of uniform rotation, kinematic asymmetries, or streams. The stars show a strong
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10

Tinker, Jeremy L., Joel R. Brownstein, Hong Guo, et al. "The Correlation between Halo Mass and Stellar Mass for the Most Massive Galaxies in the Universe." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/624043.

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We present measurements of the clustering of galaxies as a function of their stellar mass in the Baryon Oscillation Spectroscopic Survey. We compare the clustering of samples using 12 different methods for estimating stellar mass, isolating the method that has the smallest scatter at fixed halo mass. In this test, the stellar mass estimate with the smallest errors yields the highest amplitude of clustering at fixed number density. We find that the PCA stellar masses of Chen et al. clearly have the tightest correlation with halo mass. The PCA masses use the full galaxy spectrum, differentiating
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11

Vidal-García, A., S. Charlot, G. Bruzual, and I. Hubeny. "Modelling ultraviolet-line diagnostics of stars, the ionized and the neutral interstellar medium in star-forming galaxies." OXFORD UNIV PRESS, 2017. http://hdl.handle.net/10150/625298.

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We combine state-of-the-art models for the production of stellar radiation and its transfer through the interstellar medium (ISM) to investigate ultraviolet-line diagnostics of stars, the ionized and the neutral ISM in star-forming galaxies. We start by assessing the reliability of our stellar population synthesis modelling by fitting absorption-line indices in the ISM-free ultraviolet spectra of 10 Large Magellanic Cloud clusters. In doing so, we find that neglecting stochastic sampling of the stellar initial mass function in these young (similar to 10-100 Myr), low-mass clusters affects negl
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Zahedy, Fakhri S., Hsiao-Wen Chen, Michael Rauch, and Ann Zabludoff. "HST Detection of Extended Neutral Hydrogen in a Massive Elliptical at z = 0.4." IOP PUBLISHING LTD, 2017. http://hdl.handle.net/10150/625809.

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We report the first detection of extended neutral hydrogen (H I) gas in the interstellar medium (ISM) of a massive elliptical galaxy beyond z similar to 0. The observations utilize the doubly lensed images of QSO HE 0047-1756 at z(QSO) = 1.676 as absorption-line probes of the ISM in the massive (M-star approximate to 10(11) M-circle dot) elliptical lens at z = 0.408, detecting gas at projected distances of d = 3.3 and 4.6 kpc on opposite sides of the lens. Using the Space Telescope Imaging Spectrograph, we obtain UV absorption spectra of the lensed QSO and identify a prominent flux discontinui
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13

van, Haaften Lennart M., Thomas J. Maccarone, Paul H. Sell, et al. "An Excess of Low-mass X-Ray Binaries in the Outer Halo of NGC 4472." IOP PUBLISHING LTD, 2018. http://hdl.handle.net/10150/626536.

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We present new Chandra observations of the outer halo of the giant elliptical galaxy NGC 4472 (M49) in the Virgo Cluster. The data extend to 130 kpc (28'), and have a combined exposure time of 150 ks. After identifying optical counterparts using the Next Generation Virgo Cluster Survey to remove background active galactic nuclei and globular cluster (GC) sources, and correcting for completeness, we find that the number of field low-mass X-ray binaries (LMXBs) per unit stellar V-band light increases significantly with the galactocentric radius. Because the flux limit of the complete sample corr
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Rosales, Ortega Fernando Fabián. "Multi-dimensional analysis of the chemical and physical properties of spiral galaxies." Thesis, University of Cambridge, 2010. https://www.repository.cam.ac.uk/handle/1810/224843.

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The PPAK Integral Field Spectroscopy (IFS) Nearby Galaxies Survey: PINGS, a 2-dimensional spectroscopic mosaicking of 17 nearby disk galaxies in the optical wavelength range. This project represents the first attempt to obtain continuous coverage spectra of the whole surface of a galaxy in the nearby universe. The final data set comprises more than 50000 individual spectra, covering in total an observed area of nearly 80 arcmin square. The powerful capabilities of wide-field 2D spectroscopic studies areproven. The chemical composition of the whole surface of a spiral galaxy ischaracterised for
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15

Constantin, Anca. "Linking the Power Sources of Emission-Line Galaxy Nuclei from the Highest to the Lowest Redshifts." Ohio University / OhioLINK, 2004. http://www.ohiolink.edu/etd/view.cgi?ohiou1097611827.

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16

Saro, A., S. Bocquet, J. Mohr, et al. "Optical-SZE scaling relations for DES optically selected clusters within the SPT-SZ Survey." OXFORD UNIV PRESS, 2017. http://hdl.handle.net/10150/624426.

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We study the Sunyaev-Zel'dovich effect (SZE) signature in South Pole Telescope (SPT) data for an ensemble of 719 optically identified galaxy clusters selected from 124.6 deg(2) of the Dark Energy Survey (DES) science verification data, detecting a clear stacked SZE signal down to richness lambda similar to 20. The SZE signature is measured using matched-filtered maps of the 2500 deg(2) SPT-SZ survey at the positions of the DES clusters, and the degeneracy between SZE observable and matched-filter size is broken by adopting as priors SZE and optical mass-observable relations that are either cal
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17

Belfiore, Francesco M. C. "Star formation, quenching and chemical enrichment in local galaxies from integral field spectroscopy." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/266684.

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Within the currently well-established ΛCDM cosmological framework we still lack a satisfactory un- derstanding of the processes that trigger, regulate and eventually quench star formation on galactic scales. Gas flows (including inflows from the cosmic web and supernovae-driven outflows) are con- sidered to act as self-regulatory mechanisms, generating the scaling relations between stellar mass, star formation rate and metallicity observed in the local Universe by large spectroscopic surveys. These surveys, however, have so far been limited by the availability of only one spectrum per galaxy.
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18

Fields, Dale L. "Absorption-line measurements of AGN outflows." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1155913695.

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19

Gutkin, Julia. "Constraints on the physical properties and chemical evolution of star-forming gas in primeval galaxies." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066255/document.

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Je présente un nouveau modèle d'émission nébulaire de galaxies à formation d'étoiles, que j'ai développé en combinant un modèle récent de synthèse de populations stellaires avec un code classique de photoionisation. Je détaille les principales caractéristiques de ce nouveau modèle, comme le traitement sophistiqué des abondances individuelles et des déplétions sur les grains de poussière qui permet d'explorer de façon appropriée les signatures des rapports non solaires d'abondances de métaux, et donc les propriétés des galaxies chimiquement jeunes à l'époque de la réionisation. Je présente la g
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Ballero, Silvia Kuna. "Evolution of chemical abundances in active and quiescent spiral bulges." Doctoral thesis, Università degli studi di Trieste, 2008. http://hdl.handle.net/10077/2560.

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2006/2007<br>In this thesis I develop a chemical evolution model which takes advantage of the most recent high-quality abundance observations in the Galactic bulge to put constraints on its formation and evolution and to obtain a baseline model for bulges in general. I adopt updated massive star nucleosynthesis and follow the evolution of several alpha-elements and Fe by varying the evolutionary parameters. The [alpha/Fe] ratios in the bulge are correctly predicted to be supersolar for a wide range in [Fe/H], and the stellar metallicity distribution is reproduced assuming a short formation tim
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Rémy-Ruyer, Aurélie. "Probing the impact of metallicity on the dust properties in galaxies." Thesis, Paris 11, 2013. http://www.theses.fr/2013PA112340/document.

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Alors que les galaxies évoluent, leur milieu interstellaire (MIS) s’enrichit continuellement en métaux, et cet enrichissement influence la formation d’étoiles. Les galaxies naines de faible métallicité de l’Univers Local sont les candidates idéales pour étudier l’influence de cet enrichissement en métaux sur les propriétés du MIS des galaxies et nous donne un aperçu des processus d’enrichissement et de formation stellaire dans des conditions proches de celles trouvées dans les systèmes pauvres en métaux de l’Univers primordial. Des études précédentes ont montré que le MIS des galaxies naines p
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Spitoni, Emanuele. "The effects of galactic fountains on the chemical evolution of galaxies." Doctoral thesis, Università degli studi di Trieste, 2010. http://hdl.handle.net/10077/3435.

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2008/2009<br>In this thesis we study the effect of galactic fountains, namely gas and flows from the disk of galaxies produced by multiple supernova explosions, on the chemical evolution of galaxies. Sequential supernova explosions create a superbubble, whereas the swept up interstellar medium is concentrated in a supershell which can break out a stratified medium, producing bipolar outflows. The gas of the supershells can fragment into clouds which eventually fall toward the disk producing so-called galactic fountains. Many works in literature have dealt with superbubble expansion in strati
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Trevisan, Marina. "Formação e evolução de galáxias: populações estelares na Via Láctea, galáxias elípticas e propriedades de galáxias em grupos." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/14/14131/tde-18042012-162353/.

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Entender como as galáxias se formam e evoluem ao longo do tempo é um dos maiores desafio da cosmologia moderna. Vários processos estão presentes na formação de galáxias, tais como o feedback de supernovas e núcleos galácticos ativos, evolução química e dinâmica, e também efeitos ambientais. Esta tese abrange estes processos, a partir de um ponto de vista observacional. A Via Láctea tem um papel fundamental na compreensão dos vários processos envolvidos na formação de uma galáxia, e começamos nosso projeto estudando nossa própria galáxia. Diferentes processos deixam assinaturas típicas na distr
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Rojas-Arriagada, Álvaro. "Étude du bulbe galactique avec le Gaia-ESO survey." Thesis, Université Côte d'Azur (ComUE), 2016. http://www.theses.fr/2016AZUR4056/document.

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Le bulbe Galactique, est cruciale pour comprendre les processus physiques responsables de la formationde la galaxie. L'étude spectroscopique des étoiles vieilles de faible masse permettre de caractériser endétail la chimie et la cinématique du bulbe. Dans cette thèse, nous avons utilisé des données provenantdu Gaia-ESO survey pour mener une étude détaillée du système du disque ainsi que du bulbeGalactique. La distribution de métallicité du bulbe est bimodale. La population riche en métaux montreune cinématique typique de la barre. Elle présente une caractéristique de double RC et recouvre lasé
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Titarenko, Anastasia. "Indicateurs chimiques d’âge stellaire à l’ère de Gaia." Thesis, Université Côte d'Azur (ComUE), 2018. http://www.theses.fr/2018AZUR4065/document.

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Les étoiles enregistrent le passé dans leurs âges, leurs compositions chimiques et leur cinématique. Elles peuvent fournir des contraintes détaillées sur les premières époques de la formation des galaxies, jusqu’aux redshifts supérieurs à deux (un recul d’environ 10 milliards d’années). En particulier, les âges stellaires sont essentiels pour la compréhension de l’histoire de la Voie Lactée et pour la comparaison avec les modèles d’évolution galactique.L’avènement de la mission spatiale Gaia ouvre la voie à l’estimation de l’âge pour de grands échantillons d’étoiles. En particulier, les méthod
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Cesetti, Mary. "Observational constraints to the stellar populations in the center of galactic spheroids." Doctoral thesis, Università degli studi di Padova, 2009. http://hdl.handle.net/11577/3426046.

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Galactic spheroids represent one of the key challenges to our understanding of galaxies formation and evolution as far as their star-formation history is concerned. The knowledge of the stellar content of early-type galaxies is fundamental to understand their star formation and chemical evolution. The thesis is focused on two main topics, both concerned with the study of unresolved stellar populations in the centers of galaxies. The first one is a comprehensive study of the photometrical properties of three galaxies that belong to the Virgo Cluster and host Nuclear Stellar Disks (NSD) in thei
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Boeche, Corrado. "Chemical gradients in the Milky Way from unsupervised chemical abundances measurements of the RAVE spectroscopic data set." Phd thesis, Universität Potsdam, 2011. http://opus.kobv.de/ubp/volltexte/2011/5247/.

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The present thesis was born and evolved within the RAdial Velocity Experiment (RAVE) with the goal of measuring chemical abundances from the RAVE spectra and exploit them to investigate the chemical gradients along the plane of the Galaxy to provide constraints on possible Galactic formation scenarios. RAVE is a large spectroscopic survey which aims to observe spectroscopically ~10^6 stars by the end of 2012 and measures their radial velocities, atmospheric parameters and chemical abundances. The project makes use of the UK Schmidt telescope at Australian Astronomical Observatory (AAO) in Si
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Blanco-Cuaresma, Sergi. "Test de la technique de marquage chimique avec des amas ouverts." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0079/document.

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Contexte. Les étoiles naissent ensemble dans des nuages moléculaires géants. Si nous faisons l’hypothèse qu’ils étaient à l’origine chimiquement homogènes et bien mélangés, nous nous attendrions à ce que les étoiles issues d’un même nuage aient la même composition chimique. La plupart des groupes d’étoiles sont perturbés lors de leur évolution dans la galaxie et l’information dynamique est perdue. Ainsi la seule possibilité que nous ayons de reconstruire l’histoire de la formation stellaire est d’analyser les abondances chimiques que l’on observe aujourd’hui.But. La technique de marquage chimi
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Thévenin, Frédéric. "Contribution a l'etude des abondances des populations stellaires." Paris 7, 1987. http://www.theses.fr/1987PA077294.

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Presentation des resultats et difficultes rencontres en abordant les problemes d'evolution des galaxies et plus precisement de la galaxie. Un exemple d'application sur les etoiles naines f montre qu'elles ne subissent aucune anomalie d'abondances en elements lourds par la physique particuliere de leurs atmospheres. La spectrometrie a basse resolution ( equiv. A 2a) est abordee. Une application a la structure galactique et a la photometrie rgu de bale est presentee. Le spectrometre multifentes essefem qui repond au besoin de spectrographie statistique est presente et discut
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Guiglion, Guillaume. "Étude du disque galactique par marquage chimique de ses populations stellaires." Thesis, Nice, 2015. http://www.theses.fr/2015NICE4114/document.

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L'étude de la composition chimique et de la cinématique des étoiles de la Voie Lactée est essentielle afin de comprendre comment les grandes structures de notre Galaxie se sont formées. Les étoiles de faible masse gardent en mémoire dans leur atmosphère la composition chimique du milieu interstellaire dans lequel elles sont nées, et leur cinématique est essentielle afin de caractériser les différentes populations stellaires. Dans cette thèse, nous étudions le disque galactique, composante majeure de notre Galaxie. Dans le cadre de la mission spatiale Gaia, nous avons développé une procédure au
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Santos-Peral, Pablo. "Archéologie galactique du disque de la Voie Lactée avec la mission spatiale Gaia." Thesis, Université Côte d'Azur, 2021. http://www.theses.fr/2021COAZ4001.

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L’Archéologie Galactique a pour objectif de révéler l’histoire de la Voie Lactée grâce à l’analyse de différentes propriétés stellaires: des abondances chimiques, de la cinématique, de la dynamique et de l’âge. En particulier, l’abondance d’éléments α (e.g. O, Mg, Si, S, Ca, Ti) par rapport au fer ([α/Fe]) est une importante signature fossile pour tracer l’évolution chimique des populations du disque Galactique, i.e. les disques épais et mince. Le but de cette thèse est d’explorer les différentes contraintes relatives à la determination précise d’abondances à partir des spectres stellaires obs
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Nandakumar, Govind. "L’archéologie galactique et son application au centre galactique." Thesis, Université Côte d'Azur (ComUE), 2018. http://www.theses.fr/2018AZUR4064/document.

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L'archéologie galactique consiste à disséquer et analyser les nombreuses composantes de la Voie Lactée afin de mettre en évidence et distinguer les processus physiques qui contribuent à sa formation et son évolution. Ceci est possible grâce à une estimation précise des positions, des vitesses ainsi que des propriétés de l'atmosphère stellaire des étoiles individuelles qui appartiennent aux différents populations stellaires qui composent chacune de ces composantes. De ce fait, ce domaine dépend non seulement d'observations photométriques, astrométriques et spectroscopiques permettant de mesurer
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Neves, Vasco. "Étude sur les paramétres stellaires des naines M et leur lien à la formation planétaire." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENY082/document.

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Au moment d'écrire ma Thèse plus de 900 exoplanètes été annoncées et plus de 2700 planètes détectées par le télescope spatial Kepler sont en attente d'être confirmées. La haute précision des spectres et des courbes de lumière obtenue dans les relevés Doppler et transit, permet l'étude détaillée des paramètres des étoiles hôtes, et ouvre la possibilité d'enquêter sur les corrélations étoile planètes. En outre, la détermination des paramètres stellaires avec précision est un besoin critique pour déterminer les paramètres planétaires, à savoir, la masse, le rayon et la densité.Dans le cas des nai
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Dias, Bruno Moreira de Souza. "Formation and evolution of globular clusters in the Galaxy and Magellanic Clouds." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/14/14131/tde-26082014-090039/.

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Globular clusters are tracers of the formation and evolution of their host galaxies. Kinematics, chemical abundances, age and position of the clusters allows tracing interactions between Milky Way and surrounding galaxies and outlines their chemical enrichment history. In this thesis we analyse mid-resolution spectra of about 800 red giant stars in 51 Galactic globular clusters. It is the first time that [Fe/H] and [Mg/Fe] derived in a consistent way are published for such a huge sample of globular clusters, almost 1/3 of the total number of catalogued clusters. Our metallicities are showed to
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Evans, Ian Nigel. "Calibration of the H II region abundance sequence and abundances in Seyfert galaxies." Phd thesis, 1986. http://hdl.handle.net/1885/138350.

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An extensive, homogeneous grid of theoretical photoionization models with conditions appropriate to observed H n regions is computed. This grid is used to develop a comprehensive set of theoretical diagnostic diagram s for H ii regions which employ ratios of prom inentemission lines to determine the ionization parameter within the nebula, and the ionization temperature of its exciting star(s). It is also possible to estimate the element-averaged m etallicity in the nebula and stars from these diagnostics. Theoretical loci for H ii regions on the principal excitation diagrams of Baldwin,
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Hempel, Angela [Verfasser]. "Classification and abundance of extremely red galaxies with R-J ≥ 5 / presented by Angela Hempel." 2004. http://d-nb.info/973946733/34.

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37

Grossauer, Jonathan. "Abundance Matching with the Galaxies of the Virgo Cluster and the Stellar-to-Halo Mass Relation." Thesis, 2012. http://hdl.handle.net/10012/7062.

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Using data from the Next Generation Virgo Cluster Survey and high-resolution simulations of Virgo cluster-like halos, we determine the stellar-to-halo mass relation (SHMR) for subhalos, using the technique of abundance matching. The subhalo SHMR differs markedly from its field galaxy counterpart, regardless of how the subhalo mass is defined (mass at z = 0, mass at infall, or maximum mass while in the field). The slope of the relation at low mass (M⋆<10^10 Msun) is in all cases steeper than the same for the field. We find conflicting indicators of whether this difference in slope indicates an
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"Green Pea Galaxies: Physical Properties of Low-redshift Analogs of High-redshift Lyman-alpha Emitters." Doctoral diss., 2018. http://hdl.handle.net/2286/R.I.50582.

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abstract: Green pea galaxies are a class of rare, compact starburst galaxies that have powerful optical emission line [OIII]$\lambda$5007. They are the best low-redshift analogs of high-redshift (z$>$2) Lyman-alpha emitting galaxies (LAEs). They provide unique opportunities to study physical conditions in high-redshift LAEs in great detail. In this dissertation, a few physical properties of green peas are investigated. The first study in the dissertation presents star formation rate (SFR) surface density, thermal pressure in HII regions, and a correlation between them for 17 green peas and 19
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Günthardt, Guillermo Iván. "Espectroscopía y fotometría de galaxias peculiares /." Doctoral thesis, 2008. http://hdl.handle.net/11086/120.

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Tesis (Doctor en Astronomía)--Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física, 2008.<br>Se realizó una selección de 70 sistemas interactuantes de tipo M51 y se hizo un estudio fotométrico en el infrarrojo cercano, donde se compararon los colores 2MASS de este tipo de sistemas con los de galaxias aisladas. También se obtuvo información espectrofotométrica en el óptico para 13 objetos de este tipo de categoría de interacción y se construyó un catálogo de 20 sistemas, a partir del cual se estudió la cinemática de las distintas componentes.<br>Guillermo I. Günthardt
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Άκρας, Σταύρος. "Ανίχνευση και μελέτη φαινομένων μεσοαστρική ύλης". Thesis, 2010. http://nemertes.lis.upatras.gr/jspui/handle/10889/3289.

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Ο σκοπός της παρούσας διδακτορικής διατριβής ήταν η μελέτη δύο σημαντικών φαινομένων μεσοαστρική ύλης όπως είναι τα Πλανητικά Νεφελώμάτα (ΠΝ) και η ράβδος των σπειροειδών γαλαξιών. Πιο συγκεκριμένα, μελετήθηκαν 44 ΠΝ στην περιοχή του Γαλαξιακού σφαιροειδούς (Boumis et al. 2003; 2006) και προσδιορίστηκαν οι φυσικοί παράμετροι τους, όπως είναι η ενεργός θερμοκρασία και η λαμπρότητα του κεντρικού αστεριού, η πυκνότητα και η θερμοκρασία των ηλεκτρονίων, η αφθονία των Ηe, N, O, S κτλ., χρησιμοποιώντας το μοντέλο φωτο-ιονισμού Cloudy (Akras et al. 2010a). Επίσης, μελετήθηκε η ράβδος των γαλαξιών, χρ
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Nicholls, David Conway. "Nebular metallicities in isolated dwarf irregular galaxies." Phd thesis, 2014. http://hdl.handle.net/1885/11923.

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The motive for this work was to investigate whether small, isolated gas-rich galaxies show evidence of chemical evolution, by studying their nebular metallicities. I have identified a sample of 83 objects chosen for low luminosity and mass, the presence of active star formation, and isolation from other galaxies and galaxy clusters that might generate tidal effects or enrich the intergalactic medium. From these I have measured the spectra of 35 objects, using theWiFeS IFU spectrograph on the ANU 2.3m telescope at Siding Spring. In analysing spectra extracted from the WiFeS data cubes, I
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Sakari, Charli. "Chemical Abundances of Local Group Globular Clusters." Thesis, 2014. http://hdl.handle.net/1828/5621.

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Detailed chemical abundances of globular clusters in the Milky Way and M31 (the Andromeda Galaxy) are presented based on analyses of high resolution spectra. The unusual Milky Way cluster Palomar 1 (Pal 1) is studied through spectra of individual red giant branch stars; these abundances show that Pal 1 is not a classical globular cluster, and may have been accreted from a dwarf satellite of the Milky Way. The Milky Way globular clusters 47 Tuc, M3, M13, NGC 7006, and M15 are studied through their integrated light (i.e. a single spectrum is obtained for each cluster) in order to test high
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Ratsimbazafy, Ando Lalaina. "Luminous red galaxies in simulations." Thesis, 2010. http://hdl.handle.net/11394/3483.

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>Magister Scientiae - MSc<br>There have been a number of attempts to measure the expansion rate of the Universe using age-dating of Luminous Red Galaxies (LRGs).Assuming stars in LRGs form at the same time, age-dating of two populations of LRGs at different redshifts can provide an estimate of the time difference associated with the corresponding redshift interval (dt/dz). This gives a direct estimate of the Hubble parameter at the average redshift of the two populations. In this thesis, we explore the validity of the assumptions in this method using LRGs identified in the Millenium Simulation
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CURTI, MIRKO. "Assessing the chemical evolution of galaxies with large spectral surveys and spatially resolved observations." Doctoral thesis, 2018. http://hdl.handle.net/2158/1119026.

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Galaxies continuously undergo chemical enrichment. Heavy elements are produced in stars during their lifetime and then dispersed by means of stellar winds and supernovae, contributing to the enrichment of the surrounding interstellar medium (ISM). Gas flows, including inflows from the cosmic web and supernovae- or AGN-driven outflows, also play a crucial role in the definition of the chemical enrichment level by acting as regulators of both the gas content and the amount of metals that galaxies are capable to retain in the gas-phase of the ISM. Therefore, the gas-phase metallicity represents a
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Berg, Trystyn Andrew Munro. "Metal Strong Damped Lyman Alpha Systems And Their Context With The Local Group." Thesis, 2014. http://hdl.handle.net/1828/5308.

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Damped Lyman α systems (DLAs) are useful probes of the chemical enrichment of the universe as they provide accurate abundance measurements of many chemical species. Using a sample of 30 DLAs (with large metal column densities) observed with the High Resolution Echelle Spectrometer on the Keck I telescope, the abundances of several elements (i.e. iron, zinc, chromium, silicon, sulphur, phosphorus, manganese, and boron) are derived and presented. A comparison is drawn between the abundances from these metal-rich DLAs with literature samples encompassing the largest compilation of high resolution
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