English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We study the violent phase of the merger of massive binary white dwarfsystems. Our aim is to characterize the conditions for explosive burning tooccur, and identify a possible explosion mechanism of Type Ia supernovae. Theprimary components of our model systems are carbon-oxygen (C/O) white dwarfs,while the secondaries are made either of C/O or of pure helium. We account fortidal effects in the initial conditions in a self-consistent way, and considerinitially well-separated systems with slow inspiral rates. We study the mergerevolution using an adaptive mesh refinement, reactive, Eulerian code in threedimensions, assuming symmetry across the orbital plane. We use a co-rotatingreference frame to minimize the effects of numerical diffusion, and solve forself-gravity using a multi-grid approach. We find a novel detonation mechanismin C/O mergers with massive primaries. Here the detonation occurs in theprimary's core and relies on the combined action of tidal heating, accretionheating, and self-heating due to nuclear burning. The exploding structure iscompositionally stratified, with a reverse shock formed at the surface of thedense ejecta. The existence of such a shock has not been reported elsewhere.The explosion energy ($1.6\times 10^{51}$ erg) and $^{56}$Ni mass (0.86M$_\odot$) are consistent with a SN Ia at the bright end of the luminositydistribution, with an approximated decline rate of $\Delta m_{15}(B)\approx0.99$. Our study does not support double-detonation scenarios in the case of asystem with a 0.6 M$_\odot$ helium secondary and a 0.9 M$_\odot$ primary.Although the accreted helium detonates, it fails to ignite carbon at the baseof the boundary layer or in the primary's core.

No double detonations but core carbon ignitions in high-resolution, grid-based simulations of binary white dwarf mergers