New white dwarfs for the stellar initial mass-final mass relation

Original · EN

We present the preliminary results of a survey of the open clusters NGC3532 and NGC2287 for new white dwarf members which can help improve understanding of the form of the upper end of the stellar initial mass-final mass relation. We identify four objects with cooling times, distances and proper motions consistent with membership of these clusters. We find that despite a range in age of 100Myr the masses of the four heaviest white dwarfs in NGC3532 span the narrow mass interval M 0.9-1.0Msolar suggesting that the initial mass-final mass relation is relatively flatter over 4.5Msolar < Mᵢnit < 6.5Msolar than at immediately lower masses. Additionally, we have unearthed WD J0646-203 which is possibly the most massive cluster white dwarf identified to date. With M 1.1Msolar it seems likely to be composed of ONe and has a cooling time consistent with it having evolved from a single star.