Type Ia supernovae (SNe Ia) play a crucial role as standardizable cosmological candles, though the nature of their progenitors is a subject of active investigation. Recent observational and theoretical work has pointed to merging white dwarf binaries, referred to as the double-degenerate channel, as the possible progenitor systems for some SNe Ia. Additionally, recent theoretical work suggests that mergers which fail to detonate may produce magnetized, rapidly rotating white dwarfs. In this paper, we present the first multidimensional simulations of the post-merger evolution of white dwarf binaries to include the effect of the magnetic field. In these systems, the two white dwarfs complete a final merger on a dynamical timescale, and are tidally disrupted, producing a rapidly rotating white dwarf merger surrounded by a hot corona and a thick, differentially rotating disk. The disk is strongly susceptible to the magnetorotational instability (MRI), and we demonstrate that this leads to the rapid growth of an initially dynamically weak magnetic field in the disk, the spin-down of the white dwarf merger, and to the subsequent central ignition of the white dwarf merger. Additionally, these magnetized models exhibit new features not present in prior hydrodynamic studies of white dwarf mergers, including the development of MRI turbulence in the hot disk, magnetized outflows carrying a significant fraction of the disk mass, and the magnetization of the white dwarf merger to field strengths similar to 2 x 10(8) G. We discuss the impact of our findings on the origins, circumstellar media, and observed properties of SNe Ia and magnetized white dwarfs.
- THE POST-MERGER MAGNETIZED EVOLUTION OF WHITE DWARF BINARIES: THE DOUBLE-DEGENERATE CHANNEL OF SUB-CHANDRASEKHAR TYPE Ia SUPERNOVAE AND THE FORMATION OF MAGNETIZED WHITE DWARFS
- Suoqing Ji - University of Massachusetts DartmouthRobert T. Fisher - University of Massachusetts DartmouthEnrique Garcia-Berro - Univ Politecn Cataluna, Dept Fis Aplicada, E-08860 Castelldefels, SpainPetros Tzeferacos - University of ChicagoGeorge Jordan - University of ChicagoDongwook Lee - University of ChicagoPablo Loren-Aguilar - University of ExeterPascal Cremer - University of BonnJan Behrends - Freie Universität Berlin
- The Astrophysical journal, Vol.773(2), pp.1-14
- Iop Publishing Ltd
- 14
- English
- AYA2011-23102 / MCINN grant EUI2009-04167 / ESF EUROGENESIS project AST-0909132 / National Science Foundation; National Science Foundation (NSF) American Astronomical Society FA9550-10-1-0354 / AFOSR DURIP; United States Department of Defense; Air Force Office of Scientific Research (AFOSR) European Union FEDER funds; European Union (EU) B523820 / University of Chicago in part by the U.S. Department of Energy (DOE) AGAUR; Agencia de Gestio D'Ajuts Universitaris de Recerca Agaur (AGAUR) S10 RR029030-01 / Argonne National Laboratory; United States Department of Energy (DOE) CNS-0959382 / NSF; National Science Foundation (NSF)
- Department of Physics
- Journal article
- 9914417701901301