Infrared-excess white dwarfs in the Gaia 100 pc sample
We analyse the 100¿pc Gaia white dwarf volume-limited sample by means of VOSA (Virtual Observatory SED Analyser) with the aim of identifying candidates for displaying infrared excesses. Our search focuses on the study of the spectral energy distribution (SED) of 3733 white dwarfs with reliable infra...
| Autores: | , , , , , |
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| Tipo de documento: | artigo |
| Data de publicação: | 2019 |
| País: | España |
| Recursos: | Universitat Politècnica de Catalunya (UPC) |
| Repositório: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglês |
| OAI Identifier: | oai:upcommons.upc.edu:2117/179884 |
| Acesso em linha: | https://hdl.handle.net/2117/179884 https://dx.doi.org/10.1093/mnras/stz2423 |
| Access Level: | Acceso aberto |
| Palavra-chave: | White dwarf stars Brown dwarf stars Astronomy--Observations Circumstellar matter--Observations Virtual observatory tools Brown dwarfs Circumstellar matter White dwarfs Estels nans Astronomia -- Observacions Àrees temàtiques de la UPC::Aeronàutica i espai |
| Resumo: | We analyse the 100¿pc Gaia white dwarf volume-limited sample by means of VOSA (Virtual Observatory SED Analyser) with the aim of identifying candidates for displaying infrared excesses. Our search focuses on the study of the spectral energy distribution (SED) of 3733 white dwarfs with reliable infrared photometry and GBP - GRP colours below 0.8 mag, a sample that seems to be nearly representative of the overall white dwarf population. Our search results in 77 selected candidates, 52 of which are new identifications. For each target, we apply a two-component SED fitting implemented in VOSA to derive the effective temperatures of both the white dwarf and the object causing the excess. We calculate a fraction of infrared-excess white dwarfs due to the presence of a circumstellar disc of 1.6 ± 0.2 per¿cent, a value that increases to 2.6 ± 0.3 per¿cent if we take into account incompleteness issues. Our results are in agreement with the drop in the percentage of infrared excess detections for cool (<8000¿K) and hot (>20¿000¿K) white dwarfs obtained in previous analyses. The fraction of white dwarfs with brown dwarf companions we derive is ¿0.1–0.2 per¿cent. |
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