2025/10/03 by Hila Glanz, Glanz, Hila, Hagai B. Perets +3 · 1 citation
Physics and Astronomy · #astro-ph.HE #astro-ph.SR
paper · pdf · doi:10.48550/arxiv.2510.03396
published as Journal of High Energy Astrophysics 55 (2027) 100711 · 9 pages, 4 figures, 2 tables. Published in the Journal for High Energy Astrophysics
arxiv created 2026/07/28 · arxiv updated 2026/07/30
We present three-dimensional hydrodynamical simulations of mergers between low-mass hybrid HeCO white dwarfs (WDs), offering new insights into the diversity of thermonuclear transients. Unlike previously studied mergers involving higher-mass HeCO WDs and CO WDs, where helium detonation often triggers core ignition, our simulations reveal incomplete helium shell detonations in comparable-mass, lower-mass WD pairs. The result is a faint, rapidly evolving transient driven by the ejection of intermediate-mass elements and radioactive isotopes such as 48Cr and 52Fe, without significant 56Ni production. These transients may be detectable in upcoming wide-field surveys and could account for a subset of faint thermonuclear supernovae. Long-term evolution of the merger remnant shows that high-velocity PG-1159-type stars might be formed through this scenario, similar to normal CO-CO white dwarf mergers. This work expands our understanding of white dwarf mergers and their implications for nucleosynthesis and stellar evolution.