Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 29 for “"globular cluster"”.
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Extragalactic Globular Cluster Systems
Das Ziel dieser Dissertation ist die spektroskopische Studie von extragalaktischen Kugelsternhaufensystemen. Ihre Motivation ist das bessere Verstaendnis der Bildung und Entwicklung dieser Kugelsternhaufensysteme und ihrer Wirtsgalaxien. Zu diesem Zweck werden spektroskopische Linienindices des …
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Fokker-Planck models and globular cluster evolution
Numerical models for globular cluster evolution using the orbit-averaged Fokker-Planck equation are compared with observations of the globular clusters M71 and NGC 6397. The first set of models studied includes a mass spectrum, a tidal boundary and allows for a central energy source from the …
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Monte-Carlo simulations of globular cluster dynamics
… for the dynamical evolution of dense globular star clusters. Our new study was motivated in part by the wealth of new data made available from the latest optical, radio, and X-ray observations of globular clusters by various satellites and ground-based observatories, and in part by …
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The globular cluster luminosity functions of brightest cluster galaxies
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 1997.
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The Evolution of and Starburst-AGN Connection in Luminous and Ultraluminous Infrared Galaxies and their Link to Globular Cluster Formation
… of galaxy evolution involving heavy formation of globular clusters (GCs). It has been suggested that a large number of stellar clusters form during the merging of two gas-rich disk galaxies, leading to open and young massive clusters with the latter likely evolving into GCs. Furthering our …
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Constraining the Origin of Multiple Stellar Populations in Stellar Clusters
Globular clusters were among the first luminous objects to form in the Universe. They are dense collections of hundreds of thousands of stars. Globular cluster formation is a major unsolved problem in astrophysics. A new constraint on the problem came from the discovery of unexpected star-to-star …
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A self contamination model for the formation of globular star clusters
This thesis describes a model of globular cluster formation which allows the self contamination of the cluster by an earlier generation of massive stars. It is first shown that such self-contamination naturally produces an [Fe/H] in the range from -2.5 to -1.0, precisely the same range observed in …
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A self-contamination model for the formation of globular star clusters
This thesis describes a model of globular cluster formation which allows the self contamination of the cluster by an earlier generation of massive stars. It is first shown that such self-contamination naturally produces an (Fe/H) in the range from $-$2.5 to $-$1.0, precisely the same range observed …
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Precision CCD photometry of globular clusters
… of colour-magnitude photometry of Galactic globular clusters. A survey has been made of recently-published colourmagnitude photometry of globular clusters, and a self-consistent distance scale established for these data, using the method of subdwarf matching to the observed main sequences. …
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The relationship between the morphology and kinematics of galaxies and its dependence on dark matter halo structure in simulated galaxies
… galaxies with mass M* > 10^9.5 Msun and their globular cluster (GC) populations in the EAGLE spinoff project E-MOSAICS that incorporates the MOSAICS model of stellar cluster formation and evolution. We find that metal-poor and metal-rich GC populations (split by a threshold at [Fe=H] = -1) …
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On the Interaction of Jets with the Dense Medium of the Early Universe
… To understand these centers of proto-galaxy-clusters, hydrodynamic jets with cooling were simulated. After validation of the 3D code NIRVANA by comparison with literature simulations, an adiabatic 2D parameter study in the relevant regime (density contrast jet/medium eta=10^{-2}-10^{-5} was …
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Galactic dynamics : multiple tracers and gravitational lensing
… is quantified. Second, when studying the Globular Cluster (GC) system of the nearby Elliptical M87, this new approach yields information on the GC subpopulations, the luminous mass and DM profile. Inference on the GC orbital structure is discussed, with an eye to the processes of assembly …
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Search and characterization of pulsars in southern globular clusters: new methodologies and results from an S-band survey
… thesis explores the search for radio pulsars in globular clusters and the development of computational methods to enhance their detection under challenging observational conditions. Pulsars are rapidly rotating neutron stars---remnants of supernova explosions---and represent some of the most …
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Very old and very young compact objects : X-ray studies of galactic globular clusters and recent core-collapse supernovae
… of research, namely, X-ray studies of Galactic globular clusters and X-ray studies of recent core collapse supernovae. My analyses of the Chandra X-ray Observatory observations of the globular clusters NGC 6752 and NGC 6440 revealed as many low-luminosity X-ray sources as was in the entire …
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Solving the N-body problem in astrophysics
… Collisional N-body problems include open and globular clusters and protoplanetary disks during the stage, typically lasting hundreds of Myrs, when planetary embryos collide and merge. In the first part of this Thesis, I develop new symplectic integrators which provide a solution for the N-body …
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Understanding massive disk galaxy formation through resolved stellar populations
… photometry. Based on the largest sample of globular clusters ever used for such studies, we quantify the relation between metallicity and color in the widely used HST ACS filters F606W and F814W. We use a sample of globular clusters from the ACS Globular Cluster Survey and measure their RGB …
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Exploring dark matter locally via a hierarchy of stellar systems
… the profile of the tidal tails of a disrupting globular cluster and compare our results to the Pal 5 tidal tail system. We find that a close encounter with a massive dark matter subhalo could produce features in the tails that resemble the current observations. We also show that the Pal 5 system …
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Gamma-ray emission from Galactic millisecond pulsars: Implications for dark matter indirect detection
… the Fermi data from directions of Galactic globular clusters. The globular clusters are thought to be shining in gamma rays because of the MSP population they host. By analyzing their gamma-ray spectra, we reveal evidence for an IC component in the high-energy tail of Fermi data. Based on …
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On the complex stellar populations of ancient stellar systems
… tions in dwarf spheroidal galaxies and Galactic globular clusters. I use a combination of observational and modelling techniques to shed light on the detailed stellar properties of these objects. Part of my investigation focuses on the horizontal branch of dwarf spheroidal galaxies. By careful …
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