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Title: The ignition of carbon detonations via converging shock waves in white dwarfs

The progenitor channel responsible for the majority of Type Ia supernovae is still uncertain. One emergent scenario involves the detonation of a He-rich layer surrounding a C/O white dwarf, which sends a shock wave into the core. The quasi-spherical shock wave converges and strengthens at an off-center location, forming a second, C-burning, detonation that disrupts the whole star. In this paper, we examine this second detonation of the double detonation scenario using a combination of analytic and numeric techniques. We perform a spatially resolved study of the imploding shock wave and outgoing detonation and calculate the critical imploding shock strengths needed to achieve a core C detonation. We find that He detonations in recent two-dimensional simulations yield converging shock waves that are strong enough to ignite C detonations in high-mass C/O cores, with the caveat that a truly robust answer requires multi-dimensional detonation initiation calculations. We also find that convergence-driven detonations in low-mass C/O cores and in O/Ne cores are harder to achieve and are perhaps unrealized in standard binary evolution.
Authors:
 [1] ;  [2]
  1. Department of Astronomy and Theoretical Astrophysics Center, University of California, Berkeley, CA 94720 (United States)
  2. Kavli Institute for Theoretical Physics and Department of Physics, Kohn Hall, University of California, Santa Barbara, CA 93106 (United States)
Publication Date:
OSTI Identifier:
22357144
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 785; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABUNDANCE; CONVERGENCE; EXPLOSIONS; IGNITION; LAYERS; MASS; NUCLEAR REACTIONS; NUCLEOSYNTHESIS; SHOCK WAVES; SIMULATION; SPHERICAL CONFIGURATION; SUPERNOVAE; TWO-DIMENSIONAL CALCULATIONS; WHITE DWARF STARS