Faint calcium-rich transient from a double detonation of a 0.6 M⊙ carbon-oxygen white dwarf star

• Verfasst von: Morán Fraile, Javier [VerfasserIn]
• Verfasst von: Holas, Alexander [VerfasserIn]
• Verfasst von: Röpke, Friedrich [VerfasserIn]
• Verfasst von: Pakmor, Rüdiger [VerfasserIn]
• Verfasst von: Schneider, Fabian [VerfasserIn]
• Titel: Faint calcium-rich transient from a double detonation of a 0.6 M⊙ carbon-oxygen white dwarf star
• Verf.angabe: Javier Morán-Fraile, Alexander Holas, Friedrich K. Röpke, Rüdiger Pakmor, and Fabian R.N. Schneider
• E-Jahr: 2024
• Jahr: 04 March 2024
• Umfang: 7 S.
• Fussnoten: Im Titel ist M[symbol sun] als Abkürzung für die astronomische Maßeinheit Sonnenmasse dargestellt ; Im Text ist "⊙" tiefgestellt ; Gesehen am 09.09.2024
• Titel Quelle: Enthalten in: Astronomy and astrophysics
• Ort Quelle: Les Ulis : EDP Sciences, 1969
• Jahr Quelle: 2024
• Band/Heft Quelle: 683(2024) vom: März, Artikel-ID A44, Seite 1-7
• ISSN Quelle: 1432-0746
• DOI: doi:10.1051/0004-6361/202347769
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1902148894

Abstract

We have computed a 3D hydrodynamic simulation of the merger between a massive (0.4 M ) helium white dwarf (He WD) and a low-mass (0.6 M ) 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 during the first few weeks after the explosion. The explosion only yields <0.01 M of 56Ni, resulting in a low-luminosity Type Ia supernova-like light curve 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 ∆mbol 15 ≈ 1.5 mag. Both its light curve shape and spectral appearance resemble the appearance of Ca-rich transients, suggesting such mergers as a possible progenitor scenario for this class of events.