Initial Results From the Lick-Arizona White Dwarf Survey
14th European Workshop on White Dwarfs, ASP Conference Series
White dwarfs (WDs) in young open clusters provide unique insight into two different but important areas of astrophysics. First, what is the minimum mass of core-collapse supernova progenitors (Mcrit)? The range of allowed values of Mcrit (≈ 6M☉-10M☉) results in a factor of two uncertainty in the number of supernovae and the duration of the supernova phase in starburst regions, making the precise value of Mcrit vital to the understanding of galaxy evolution. The second question addressed by young open cluster WDs is, what is the relationship between the WD mass and its progenitor mass? This initial-final mass relation (IFMR) is quite uncertain, especially at the high-mass end, and is not well-constrained theoretically. We present initial results from the Lick-Arizona White Dwarf Survey study of the open cluster M35 (NGC 2168). We detect eight hot, massive white dwarfs, seven of which are likely to be cluster members. Two of these cluster white dwarfs show indications of escaping from the open cluster, providing evidence that the deficit of WDs observed in many open clusters may be due to preferential dynamical loss of WDs. The data also represent a doubling in the number of cluster WDs with progenitor masses ≥ 4M☉. No significant difference between the IFMR derived in this work and previous empirical derivations is observed. We place a lower limit on Mcrit of 5.8M_☉ for an assumed cluster age of 150 Myr.
Physics and Astronomy
Williams, Kurtis A. and Bolte, M., "Initial Results From the Lick-Arizona White Dwarf Survey" (2005). Faculty Publications. 171.