Evidence of spectral evolution on the white dwarf sample from the Gaia mission
Since the Gaia data release 2, several works have been published describing a bifurcation in the observed white dwarf colour−magnitude diagram for GBP−GRP>0. Some possible explanations in the literature include the existence of a double population with different initial mass functions or two dist...
| Autores: | , , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2020 |
| País: | Brasil |
| Recursos: | Universidade Federal do Rio Grande do Sul (UFRGS) |
| Repositorio: | Repositório Institucional da UFRGS |
| Idioma: | inglés |
| OAI Identifier: | oai:www.lume.ufrgs.br:10183/211713 |
| Acesso em linha: | http://hdl.handle.net/10183/211713 |
| Access Level: | acceso abierto |
| Palavra-chave: | Anãs brancas Populacoes estelares Evolucao galatica Parallax: white dwarfs |
| Resumo: | Since the Gaia data release 2, several works have been published describing a bifurcation in the observed white dwarf colour−magnitude diagram for GBP−GRP>0. Some possible explanations in the literature include the existence of a double population with different initial mass functions or two distinct populations, one formed by hydrogen-envelope and one formed by helium-envelope white dwarfs. We propose instead spectral evolution to explain the bifurcation. From a population synthesis approach, we find that spectral evolution occurs for effective temperatures below ≃11000K and masses mainly between 0.64M⊙ and 0.74M⊙, which correspond to around 16 per cent of all DA white dwarfs. We also find that the Gaia white dwarf colour–magnitude diagram indicates a star formation history that decreases abruptly for objects younger than 1.4Gyr and a top-heavy initial mass function for the white dwarf progenitors. |
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