The effect of dust and gas energetics on the clustered star formation process

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The effect of dust and gas energetics on the clustered star formation process

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dc.contributor.advisor Evans, Neal J.
dc.contributor.advisor Martel, Hugo
dc.creator Urban, Andrea, 1980-
dc.date.accessioned 2012-10-04T17:51:04Z
dc.date.available 2012-10-04T17:51:04Z
dc.date.created 2008-12
dc.date.issued 2012-10-04
dc.identifier.uri http://hdl.handle.net/2152/18159
dc.description.abstract The effect of dust/gas heating and cooling is shown to have a significant effect on the process of clustered star formation. Compared to an isothermal simulation, a simulation with a more accurate description of the equation of state produces an order of magnitude fewer stars as well as stars of much greater mass. The energetics algorithm used to calculate the dust and gas temperature includes the radiative heating of dust, dust-gas collisional heating/cooling, cosmic-ray heating, and molecular cooling. It uses DUSTY, a spherical continuum radiative transfer code, to model the dust temperature distribution around young stellar objects with various luminosities and surrounding gas and dust density distributions. The gas temperature is then determined by assuming energy balance. Before the complete energetics algorithm is included in a simulation, first only the dust heating component is included. The gas temperature is then set solely by the dust temperature. The resultant mass functions of our simulations which include heating are compared to those which assume an isothermal equation of state. We find that including dust heating severely limits star formation; we form at least an order of magnitude fewer objects when we include dust heating compared to an isothermal simulation. The mass functions from our simulations which include heating are much more similar than the mass functions from our isothermal simulations to the observed mass functions, in that they are able to form high-mass stars (M [> subscript tilde] 10M[solar mass]). The distribution of the high-mass objects is well-approximated by the Salpeter initial mass function. Including the complete energetics algorithm in a simulation produces results similar to a simulation with only dust heating. Both simulations have similar density profile parameters. The mass accretion, mass, and luminosity evolution of the sinks is also similar. The average temperature, however, is cooler than the simulation with only dust heating. We form fewer objects comparatively and are still unable to form enough low and intermediate-mass objects to replicate the observed mass function. This may be an effect of small number statistics, or possibly physical processes that are not considered in this work.
dc.format.medium electronic
dc.language.iso eng
dc.rights Copyright © is held by the author. Presentation of this material on the Libraries' web site by University Libraries, The University of Texas at Austin was made possible under a limited license grant from the author who has retained all copyrights in the works.
dc.subject.lcsh Cosmic dust
dc.subject.lcsh Interstellar matter
dc.subject.lcsh Stars--Formation
dc.title The effect of dust and gas energetics on the clustered star formation process
dc.description.department Astronomy
dc.type.genre Thesis
dc.type.material text
thesis.degree.department Astronomy
thesis.degree.discipline Astronomy
thesis.degree.grantor The University of Texas at Austin
thesis.degree.level Doctoral
thesis.degree.name Doctor of Philosophy

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