The impact of a merger episode in the galactic disc white dwarf population |
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| Authors: | Santiago Torres,Enrique Garcí a-Berro,reas Burkert,Jordi Isern |
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| Affiliation: | 1Departament de Telecomunicaciói Arquitectura de Computadors, EUP de Mataró, Universitat Politècnica de Catalunya, Av. Puig i Cadafalch 101, 08303 Mataró, Spain;2Departament de Física Aplicada, Universitat Politècnica de Catalunya, Jordi Girona Salgado s/n, Mòdul B-4, Campus Nord, 08034 Barcelona, Spain;3Institut d'Estudis Espacials de Catalunya (CSIC/UPC), Edifici Nexus, Gran Capità2-4, 08034 Barcelona, Spain;4Max-Planck-Institut für Astronomie, Koenigstuhl 17, 69117 Heidelberg, Germany;5Institut de Ciències de l'Espai, C.S.I.C., Edifici Nexus, Gran Capità2-4, 08034 Barcelona, Spain |
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| Abstract: | In this paper we analyse the consequences in the white dwarf population of a hypothetical merger episode in our Galactic disc. We have studied several different merging scenarios with our Monte Carlo simulator. For each one of these scenarios we have derived the main characteristics of the resulting white dwarf population and we have compared them with the available observational data, namely the white dwarf luminosity function and the kinematic properties of the white dwarf population. Our results indicate that very recent (less than ∼6 Gyr ago) and massive (∼16 per cent of the mass of our Galaxy) merger episodes are quite unlikely in view of the available kinematical properties of the disc white dwarf population. Smaller merger episodes (of the order of ∼4 per cent of the mass of our Galaxy) are, however, compatible with our current knowledge of those kinematical properties. Finally, we prove that the white dwarf luminosity function is quite insensitive to such a merger episode. |
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| Keywords: | stars: luminosity function, mass function white dwarfs Galaxy: stellar content |
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