The evolution of ultra-massive carbon–oxygen white dwarfs

• DOI: 10.1093/mnras/stac348
• Publication Date: 2022-02-07T20:11:48Z
• Authors: María E Camisassa; Leandro G Althaus; Detlev Koester; Santiago Torres; Pilar Gil Pons; Alejandro H Córsico
• Keywords: Black dwarf; Blue dwarf

Ultra-massive white dwarfs ($\rm M_{WD} \gtrsim 1.05\, M_{\odot}$) are considered powerful tools to study type Ia supernovae explosions, merger events, the occurrence of physical processes in Super Asymptotic Giant Branch (SAGB) phase, and existence high magnetic fields. Traditionally, ultra-massive expected harbour oxygen-neon (ONe) cores. However, new observations recent theoretical studies suggest that progenitors some can avoid carbon burning, leading formation harbouring carbon-oxygen (CO) Here we present a set dwarf evolutionary sequences with CO cores for wide range metallicity masses. We take into account energy released by latent heat phase separation during crystallization process $^{22}$Ne sedimentation. Realistic chemical profiles resulting from full computation progenitor evolution considered. compare our models ONe models. conclude evolve significantly slower than their counterparts mainly three reasons: larger thermal content, effect crystallization, also provide colors several photometric bands on basis model atmospheres. These models, together an appropriate framework population Galaxy.