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Abstract: The contribution of white dwarfs of the different Galactic populations to thestellar content of our Galaxy is only poorly known. Some authors claim a vastpopulation of halo white dwarfs, which would be in accordance with someinvestigations of the early phases of Galaxy formation claiming a top-heavyinitial-mass-function. Here, I present a model of the population of whitedwarfs in the Milky Way based on observations of the local white dwarf sampleand a standard model of Galactic structure. This model will be used to estimatethe space densities of thin disc, thick disc and halo white dwarfs and theircontribution to the baryonic mass budget of the Milky Way. One result of thisinvestigation is that white dwarfs of the halo population contribute a largefraction of the Galactic white dwarf number count, but they are not responsiblefor the lion-s share of stellar mass in the Milky Way. Another important resultis the substantial contribution of the - often neglected - population of thickdisc white dwarfs. Misclassification of thick disc white dwarfs is responsiblefor overestimates of the halo population in previous investigations.

Author: Ralf Napiwotzki


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