One-armed spiral instability in double-degenerate post-merger accretion disks
| Autor: | Robert Fisher, Gabriela Aznar-Siguán, Enrique García-Berro, Suoqing Ji, Rahul Kashyap, Pablo Lorén-Aguilar |
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| Přispěvatelé: | Universitat Politècnica de Catalunya. GAA - Grup d'Astronomia i Astrofísica |
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Angular momentum
Detonation FOS: Physical sciences Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences Instability Gravitation Mass transfer 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics white dwarfs High Energy Astrophysical Phenomena (astro-ph.HE) Physics Física [Àrees temàtiques de la UPC] 010308 nuclear & particles physics White dwarf Astronomy and Astrophysics numerical [methods] Mass ratio Stars Estels Supernova Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science instabilities Astrophysics - High Energy Astrophysical Phenomena binaries general [supernovae] |
| Zdroj: | UPCommons. Portal del coneixement obert de la UPC Universitat Politècnica de Catalunya (UPC) Recercat. Dipósit de la Recerca de Catalunya instname |
| DOI: | 10.3847/1538-4357/aa6afb |
| Popis: | Increasing observational and theoretical evidence points to binary white dwarf mergers as the origin of some if not most normal Type Ia supernovae (SNe Ia). In this paper, we discuss the post-merger evolution of binary white dwarf (WD) mergers, and their relevance to the double-degenerate channel of SNe Ia. We present 3D simulations of carbon-oxygen (C/O) WD binary systems undergoing unstable mass transfer, varying both the total mass and the mass ratio. We demonstrate that these systems generally give rise to a one-armed gravitational spiral instability. The spiral density modes transport mass and angular momentum in the disk even in the absence of a magnetic field, and are most pronounced for secondary-to-primary mass ratios larger than $0.6$. We further analyze carbon burning in these systems to assess the possibility of detonation. Unlike the case of a $1.1 + 1.0 M_{\odot}$ C/O WD binary, we find that WD binary systems with lower mass and smaller mass ratios do not detonate as SNe Ia up to $\sim8-22$ outer dynamical times. Two additional models do however undergo net heating, and their secular increase in temperature could possibly result in a detonation on timescales longer than those considered here. Accepted to Astrophysical Journal |
| Databáze: | OpenAIRE |
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