2023/10/30 by Javier Morán-Fraile, Alexander Holas, Moran-Fraile, J. +7
Medicine · Physics and Astronomy · #Cardiac Imaging and Diagnostics #FOS: Physical sciences #Gamma-ray bursts and supernovae #High Energy Astrophysical Phenomena (astro-ph.HE) #Solar and Stellar Astrophysics (astro-ph.SR)
paper · pdf · doi:10.48550/arxiv.2310.19669
openalex publication_date 2023/10/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We have computed a three-dimensional hydrodynamic simulation of the merger between a massive (0.4 M_\odot) helium white dwarf (He WD) and a low-mass (0.6 M_\odot) carbon-oxygen white dwarf (CO WD). Despite the low mass of the primary, the merger triggers a thermonuclear explosion as a result of a double detonation, producing a faint transient and leaving no remnant behind. This type of event could also take place during common-envelope mergers whenever the companion is a CO WD and the core of the giant star has a sufficiently large He mass. The spectra show strong Ca lines throughout the first few weeks after the explosion. The explosion only yields <0.01 M_\odot of 56Ni, resulting in a low-luminosity SN Ia-like lightcurve that resembles the Ca-rich transients within this broad class of objects, with a peak magnitude of Mbol ≈ -15.7 mag and a rather slow decline rate of Δm15bol≈ 1.5 mag. Both, its lightcurve-shape and spectral appearance, resemble the appearance of Ca-rich transients, suggesting such mergers as a possible progenitor scenario for this class of events.