Persistent Link:
http://hdl.handle.net/10150/290114
Title:
Gamma-ray lines from asymmetric supernovae
Author:
Hungerford, Aimee L.
Issue Date:
2004
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
High energy emission from supernovae provide a direct window into the quantity and distribution of radioactive elements produced in these explosions. Combining supernova explosion calculations with 3D Monte Carlo gamma-ray transport, I have studied the effect mixing and asymmetries have on the hard X-ray and gamma-ray spectra. Two types of asymmetries (bipolar and unipolar) are investigated, the parameters of which are motivated by the most recent findings from multi-dimensional core-collapse supernova simulations. These bipolar and unipolar asymmetries are imposed artificially on 1-dimensional stellar progenitor structures and their evolution is followed using a 3-dimensional smoothed particle hydrodynamics (SPH) code. Global asymmetries in the explosion enhance the outward mixing of heavy elements such as 56Ni, reducing the observable emergence time for the hard X-ray continuum and gamma-ray line emission over that of symmetrically mixed models. The details of the velocity asymmetry lead to very different nickel distributions in the outer envelope. The high energy spectra resulting from these models predict an angular variation for the correspondence between the emergence time of the hard X-ray continuum and the broadening of the gamma-line profiles. The unipolar explosion models, in particular, demonstrate that redshifted gamma-ray line profiles are attainable at epochs where gamma-ray emission arises predominantly from the outer extent of the nickel distribution. The departure from a symmetric explosion scenario manifests itself most clearly in the extended nickel, making gamma-ray line observations an ideal probe of the initial explosion asymmetry.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Physics, Astronomy and Astrophysics.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Astronomy
Degree Grantor:
University of Arizona
Advisor:
Pinto, Philip A.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleGamma-ray lines from asymmetric supernovaeen_US
dc.creatorHungerford, Aimee L.en_US
dc.contributor.authorHungerford, Aimee L.en_US
dc.date.issued2004en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractHigh energy emission from supernovae provide a direct window into the quantity and distribution of radioactive elements produced in these explosions. Combining supernova explosion calculations with 3D Monte Carlo gamma-ray transport, I have studied the effect mixing and asymmetries have on the hard X-ray and gamma-ray spectra. Two types of asymmetries (bipolar and unipolar) are investigated, the parameters of which are motivated by the most recent findings from multi-dimensional core-collapse supernova simulations. These bipolar and unipolar asymmetries are imposed artificially on 1-dimensional stellar progenitor structures and their evolution is followed using a 3-dimensional smoothed particle hydrodynamics (SPH) code. Global asymmetries in the explosion enhance the outward mixing of heavy elements such as 56Ni, reducing the observable emergence time for the hard X-ray continuum and gamma-ray line emission over that of symmetrically mixed models. The details of the velocity asymmetry lead to very different nickel distributions in the outer envelope. The high energy spectra resulting from these models predict an angular variation for the correspondence between the emergence time of the hard X-ray continuum and the broadening of the gamma-line profiles. The unipolar explosion models, in particular, demonstrate that redshifted gamma-ray line profiles are attainable at epochs where gamma-ray emission arises predominantly from the outer extent of the nickel distribution. The departure from a symmetric explosion scenario manifests itself most clearly in the extended nickel, making gamma-ray line observations an ideal probe of the initial explosion asymmetry.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectPhysics, Astronomy and Astrophysics.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineAstronomyen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorPinto, Philip A.en_US
dc.identifier.proquest3145077en_US
dc.identifier.bibrecord.b47210989en_US
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