Sie können Bookmarks mittels Listen verwalten, loggen Sie sich dafür bitte in Ihr SLUB Benutzerkonto ein.
Medientyp:
E-Artikel
Titel:
An evolutionary channel for CO-rich and pulsating He-rich subdwarfs
Beteiligte:
Miller Bertolami, M M;
Battich, T;
Córsico, A H;
Althaus, L G;
Wachlin, F C
Erschienen:
Oxford University Press (OUP), 2022
Erschienen in:
Monthly Notices of the Royal Astronomical Society: Letters, 511 (2022) 1, Seite L60-L65
Sprache:
Englisch
DOI:
10.1093/mnrasl/slab134
ISSN:
1745-3933;
1745-3925
Entstehung:
Anmerkungen:
Beschreibung:
Abstract Recently, a new class of hot subluminous stars strongly enriched in C and O has been discovered (CO-sdOs). These stars show abundances very similar to those observed in PG1159 stars but at lower temperatures. Moreover, it has been recently suggested that C and O enrichment might be the key ingredient driving the pulsations in He-rich hot subdwarf stars (He-sdBVs). Here, we argue that these two types of rare stars can be explained by a variant of one of the main channels forming hot subdwarf stars. The scenario involves the formation and merging of a He-core white dwarf and a less massive CO-core white dwarf. We have constructed simple merger models and computed their subsequent evolution. The merger products are in agreement with the surface parameters and composition of CO-sdOs. In addition, we have performed simulations including the effects of element diffusion and the excitation of pulsations. These simulations show that less massive merger products can form stellar structures that have surface parameters, abundances, and pulsation periods similar to those displayed by He-sdBVs. We conclude that the proposed scenario, or some variant of it, offers a very plausible explanation for the formation of CO-sdOs, pulsating He-sdBs, and low-luminosity PG1159 stars.