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 9 of 9 for “"formation of stars"”.
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The role of ambipolar diffusion in the formation of interstellar cloud cores and protostars
The formation of stars is a fundamental unsolved problem in astrophysics. Interstellar molecular clouds, observed to be the birth place of stars, have masses much larger than those of typical stars. Observed densities, temperatures, and strengths of well-ordered magnetic fields imply that magnetic …
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The role of ambipolar diffusion in the formation of interstellar cloud cores and protostars
The formation of stars is a fundamental unsolved problem in astrophysics. Interstellar molecular clouds, observed to be the birth place of stars, have masses much larger than those of typical stars. Observed densities, temperatures, and strengths of well-ordered magnetic fields imply that magnetic …
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Optical and near infrared observations of accretion processes in galactic compact objects
… present optical and near-infrared observations of compact binary systems. The observations are used to refine the binary parameters of several Low Mass X-ray Binaries, and to better understand the accretion processes in these systems. Accretion is essential in the formation of stars, planets and …
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Galaxy evolution : near and far
The formation of stars from interstellar gas is the cornerstone of galaxy evolution. This thesis represents work undertaken in order to characterise the role of cool interstellar gas, and its relation to star formation, in galaxy evolution across cosmic time. In particular, it concentrates on star …
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A Study of Quasar Outflows: Physical Characteristics and Feedback Effects
… through which the quasar can curtail the formation of stars, regulate the evolution of its host galaxy, and affect its surrounding environment in other ways. One possible mechanism for this process is a quasar's outflow, which can be observed as blueshifted absorption troughs in the …
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Molecular clouds and star formation in the Inner Galaxy
A detailed understanding of the process of star formation is crucial for modern astrophysics. Stars form from the gravitational collapse of molecular gas clouds; it is the process by which cold molecular gas is transformed into the stars and planets that make up the many billions of galaxies in the …
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Probing quasar sight lines in three dimensions
… Lyman alpha absorption (DLA) lines seen spectra of distant quasar are believed to arise when the sight line to the quasar goes trough the disc of a galaxy or a proto galaxy. Most of the neutral matter in the universe is contained in these clouds of neutral hydrogen that cause the absorption …
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Present and early star formation : a study on rotational and thermal properties
… the rotational and thermal properties of star-forming molecular clouds using hydrodynamic simulations. Stars form from molecular cloud cores by gravoturbulent fragmentation. Understanding the angular momentum and the thermal evolution of cloud cores thus plays a fundamental role in …
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Studying galaxy formation through Lyman alpha in emission and absorption
Galaxy formation is one of the central problems of Physical Cosmology. Neutral hydrogen plays an important role, linking the collapse of cooling gas into haloes with the formation of stars. Lyman alpha, hydrogen’s strongest spectral line, can directly probe neutral hydrogen in the high redshift …