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Stars, Interstellar Medium and the Galaxy Commons™
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- Accretion disks (2)
- Magnetic fields (2)
- Magnetohydrodynamics (2)
- Star formation (2)
- Cosmology: theory (1)
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- Data analysis (1)
- Formation (1)
- Gravitational collapse (1)
- Hydrodynamics (1)
- Mass function (1)
- Mathematical modelling (1)
- Model fitting (1)
- Model selection (1)
- Neural networks (1)
- Outflows (1)
- Plasma physics (1)
- Polarization (1)
- Protostars (1)
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- Stars: Pop- ulation III (1)
- Stars: formation (1)
- Stars: protostellar disks (1)
- Stellar clusters (1)
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Articles 1 - 4 of 4
Full-Text Articles in Stars, Interstellar Medium and the Galaxy
The Magnetic Field Of Protostar-Disk-Outflow Systems, Mahmoud Sharkawi
The Magnetic Field Of Protostar-Disk-Outflow Systems, Mahmoud Sharkawi
Electronic Thesis and Dissertation Repository
Recent observations of protostellar cores reveal complex magnetic field configurations that are distorted in the innermost disk region. Unlike the prestellar phase, where the magnetic field geometry is simpler with an hourglass configuration, magnetic fields in the protostellar phase are sculpted by the formation of outflows and rapid rotation. This gives rise to a significant azimuthal (or toroidal) component that has not yet been analytically modelled in the literature. Moreover, the onset of outflows, which act as angular momentum transport mechanisms, have received considerable attention in the past few decades. Two mechanisms: 1) the driving by the gradient of a …
Mathematical Modelling & Simulation Of Large And Small Scale Structures In Star Formation, Gianfranco Bino
Mathematical Modelling & Simulation Of Large And Small Scale Structures In Star Formation, Gianfranco Bino
Electronic Thesis and Dissertation Repository
This thesis aims to study the magnetic and evolutionary properties of stellar objects from the prestellar phase up to and including the late protostellar phase. Many of the properties governing star formation are linked to the core’s physical properties and the magnetic field highly dictates much of the core’s stability.
The thesis begins with the implementation of a fully analytic magnetic field model used to study the magnetic properties governing the prestellar core FeSt 1-457. The model is a direct result of Maxwell’s equations and yields a central-to-surface magnetic field ratio in the equatorial plane in cylindrical coordinates. The model …
Modeling The Mass Function Of Stellar Clusters Using The Modified Lognormal Power-Law Probability Distribution Function, Deepakshi Madaan
Modeling The Mass Function Of Stellar Clusters Using The Modified Lognormal Power-Law Probability Distribution Function, Deepakshi Madaan
Electronic Thesis and Dissertation Repository
We use the Modified Lognormal Power-law (MLP) probability distribution function to model the behaviour of the mass function (MF) of young and populous stellar populations in different environments. We begin by modeling the MF of NGC1711, a simple stellar population (SSP) in the Large Magellanic Cloud as a pilot case. We then use model selection criterion to differentiate between candidate models. Using the MLP we find that the stellar catalogue of NGC1711 follows a pure power-law behaviour below the completeness limit with the slope α = 2.75 for dN/dlnm ∝ m^(−α+1) in the mass range 0.89 M⊙ to 7.75 M⊙. …
Observational Signatures From Self-Gravitating Protostellar Disks, Alexander L. Desouza
Observational Signatures From Self-Gravitating Protostellar Disks, Alexander L. Desouza
Electronic Thesis and Dissertation Repository
Protostellar disks are the ubiquitous corollary outcome of the angular momentum conserving, gravitational collapse of molecular cloud cores into stars. Disks are an essential component of the star formation process, mediating the accretion of material onto the protostar, and for redistributing excess angular momentum during the collapse. We present a model to explain the observed correlation between mass accretion rates and stellar mass that has been inferred from observations of intermediate to upper mass T Tauri stars. We explain this correlation within the framework of gravitationally driven torques parameterized in terms of Toomre’s Q criterion. Our models reproduce both the …