Probing Post-Explosion Evolution of Supernovae in the Type Ia Single Degenerate Channel

• Other Authors: Boehner, Philip (authoraut)
• Format: Others
• Language: English; English
• Published: Florida State University
• Subjects: Astrophysics
• Online Access: http://purl.flvc.org/fsu/fd/FSU_migr_etd-9145

Two leading theories exist to explain the progenitor models of Type Ia supernovae. In the single-degenerate scenario (SDS), a carbon-oxygen white dwarf slowly accretes matter from a non-degenerate binary companion that is exceeding its roche lobe until the mass of the white dwarf reaches the Chandrasekhar limit (M ∼ 1.4 solar masses). At this point a deflagration wave begins in the core, eventually turning into a detonation wave that reaches the surface and annihilates the white dwarf, causing the supernova event. In the double-degenerate scenario (DDS), two white dwarfs lose angular momentum due to the emission of gravitational waves and merge together, exceeding the Chandrasekhar limit and causing a supernova. In this study, we explore the observational evidence indicative of only the single-degenerate scenario by looking at the long-term effects caused by the interaction between the supernova debris and the non-degenerate companion. We model the interaction in two dimensions using the PROTEUS code that utilizes adaptive mesh refinement. Our simulations involve one supernova type interacting with one of seven different companion types -- four main-sequence-like stars (MS), one subgiant (SG), and two red giants (SY). During the interaction, a region mostly devoid of material is formed behind the companion. We find that the structure of this 'hole' formed behind the companion is similar across each of these models, with an angular size extending 30°-45°. The structure of the supernova remnant is affected out to 90°-100° as a result of the interaction with the companion. Each companion type has a characteristic percentage of mass stripped from it by the end of the simulation with MS stars losing about ∼20% of their mass, the SG star losing about ∼10%, and the SY stars losing about ∼40%, where in the SY case only the denerate core and a small portion of the stellar envelope is left over. We find that the interaction contaminates the companion with trace amounts of Nickel-56. 10⁻¹⁶ to 10⁻⁸ solar masses of Nickel-56 are found in the MS stars, 10⁻⁷ solar masses are found in the SG star, and 10⁻¹⁹ to 10⁻²¹ solar masses are found in the SY stars' leftover envelope, though this contamination may be purely numerical. In the initial stages of the interaction, we find that the superheated material trapped between the companion and the expanding ejecta is capable of prompt X-ray emission through the evacuated hole once it travels around the companion and along the border of the hole. The temperature of this material is expected to decrease once it reaches the hole, but at each model's most energetic time, all three sample systems considered are capable of producing soft X-rays (for the MS38 system, the bulk of potential X-ray emission lies in the range 2.73 to 4.32 KeV, for the SG system, 1.08 to 2.43 KeV, and for the SY319 system, 0.09 to 0.27 KeV). === A Thesis submitted to the Department of Scientific Computing in partial fulfillment of the requirements for the degree of Master of Science. === Fall Semester, 2014. === October 30, 2014. === Close Binaries, General Supernovae, Hydrodynamics, Numerical Methods === Includes bibliographical references. === Tomasz Plewa, Professor Directing Thesis; Gordon Erlebacher, Committee Member; Anke Meyer-Baese, Committee Member.