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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 49 for “"spiral galaxies"”.
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Dark Matter in Spiral Galaxies
… of five high surface brightness, late type spiral galaxies NGC 3810, NGC 3893, NGC 4254, NGC 5676 and NGC 6643, which were studied with the aim to quantify the luminous-to-dark matter ratio inside their optical radii. In order to meet this goal, the galaxies' morphology and gas kinematics …
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Quantitative analysis of 3-arm spiral galaxies
A relatively small fraction of spiral galaxies has three spiral arms. It has been theorized that these "3-arm spirals" are relatively unstable and prone to decaying into even numbered patterns due to tidal interactions. We present a series of quantitative analyses on a large sample of 3-arm spiral …
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Satellite dynamics in spiral galaxies with Dark Matter haloes
… dunklen Korona (dunkle Materie) umgebenen Spiral-Galaxie. Die Hauptziele sind: (i) die Durchführung einer detaillierten theoretischen Analyse der dynamischen Reibung, d.h. des Prozesses, der die Verschmelzung der Satelliten verursacht und (ii) der Einfluss der Abplattung der dunken Korona …
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A Theory for the Bars of Barred Spiral Galaxies
Made available in DSpace on 2014-12-10T23:45:12Z (GMT). No. of bitstreams: 1 7310013.pdf: 3047786 bytes, checksum: ccbc13e00264948033e5a1ea57322d76 (MD5) Previous issue date: 1972
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Gravitational lensing of quasars by edge-on spiral galaxies
… CX2201-3201, which is lensed by an edge-on spiral galaxy. The unusually high tilt of the spiral galaxy provides us with a rare opportunity for mass modeling. In addition, the unusual placement of the two visible images of the system offers an intriguing lensing system for study-the two …
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A new model of spiral galaxies based on propagating star formation.
… potential and more importantly, to impose a spiral density wave perturbation in a natural way. Such waves arise naturally in N-body simulations where the collective forces between particles are considered explicitly, but we are more interested in its effect on the star formation rate, and …
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Effect of strong density gradients on density waves in spiral galaxies
Thesis. 1976. M.S.--Massachusetts Institute of Technology. Dept. of Earth and Planetary Sciences.
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Multi-dimensional analysis of the chemical and physical properties of spiral galaxies
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 …
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Gas distribution, star formation and giant molecular cloud evolution in nearby spiral galaxies
… resolved properties of the cold gas in nearby galaxies at different size scales, starting from the whole galactic disk to the size of the Giant Molecular Clouds (GMCs). Differences in the shape and width of global CO and HI spectra of resolved disks of spiral galaxies are systematically …
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The effects of dust on the derived photometric parameters of disks and bulges in spiral galaxies
Spiral galaxies contain large amounts of interstellar dust, that absorbs and scatters their photons. This results in strong distortions and changes of their observed stellar images from what would be observed in the absence of the dust. Because of this the measured structural parameters of spiral …
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Dark Matter Halo Concentration and the Evolution of Spiral Structure in N-Body, Barred Spiral Galaxies
… between pitch angle (the tightness of spiral arm structure in the disk), P, and various indicators of central mass concentration, as well as the theoretical relationship between halo mass concentration and the density of visible matter in the central part of the galaxy, we look at a …
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Correcting the rotation curve of spiral galaxies for the non-circular motions induced by a bar
The mass distribution of disk galaxies is usually determined through the use of rotation curves. This determination relies on two key assumptions; that the gas moves on circular orbits and that this motion traces the underlying gravitational potential. In the case of barred spiral galaxies the …
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The Universality of Intrinsic Flattening in Extragalactic Stellar Disks
Highly inclined (edge-on) galaxies provide the unique perspective necessary to constrain the intrinsic flattening, 𝑐/𝑎, of galactic disks. We use “dust-free” 3.6 𝜇m maps of 141 edge-on spiral galaxies from the Spitzer Survey of Stellar Structure in Galaxies (S4G) and its early-type galaxy extension …
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Spatially-resolved studies of nearby star-forming galaxies
Spatially-resolved studies of nearby star-forming galaxies are essential to understand various physical and chemical phenomena at play in the interstellar medium in the galaxies, and consequently to obtain a comprehensive picture of galaxy formation and evolution. In this thesis, I perform …
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Probing for optical and HI diffuse gas in MHONGOOSE galaxy UGCA 250
… ionised gas (eDIG) has been observed in external spiral galaxies as well as the Milky Way and is distinguished by its emission-line ratios and its rotational velocity lag with respect to the galactic disk. Similarly, there is a wealth of observational evidence for extraplanar gas in the form of …
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Development and Resultant Implementation of Custom Software for Analyses of Galactic Neighborhoods
The structure and organization of galaxies and their environments within the universe is a critical and fundamental question in the field of astrophysics. The amount of data available necessitates computer software to aid analyses. Previous research in the field utilized software built in FORTRAN …
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The Disk Structure of Late Type Galaxies: Determining the Black Hole Mass Function of Low Surface Brightness Galaxies Through Logarithmic Spiral Arm Pitch Angle Measurement
… to the geometric structure of late type (spiral) galaxies, specifically on the relation between the logarithmic spiral pitch angle of the galactic spiral arms with other properties of the galaxy, such as central Supermassive Black Hole (SMBH) mass. Our work continues a study of the Black …
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