Probing the Lower Mass Limit for Supernova Progenitors and the High-Mass End of the Initial-Final Mass Relation From White Dwarfs in the Open Cluster M35 (Ngc 2168)

Abstract

We present a photometric and spectroscopic study of the white dwarf (WD) population of the populous, intermediateage open cluster M35 (NGC 2168); this study expands upon our previous study of the WDs in this cluster. We spectroscopically confirm 14 WDs in the field of the cluster: 12 DAs, 1 hot DQ, and 1 DB star. For each DA, we determine the WD mass and cooling age, from which we derive each star's progenitor mass. These data are then added to the empirical initial-final mass relation (IFMR), where the M35 WDs contribute significantly to the high-mass end of the relation. The resulting points are consistent with previously published linear fits to the IFMR, modulo moderate systematics introduced by the uncertainty in the star cluster age. Based on this cluster alone, the observational lower limit on the maximum mass of WD progenitors is found to be ∼5.1 M − 5.2 M at the 95% confidence level; including data from other young open clusters raises this limit to as high as 7.1 M , depending on the cluster membership of three massive WDs and the core composition of the most massive WDs. We find that the apparent distance modulus and extinction derived solely from the cluster WDs ((m − M) V = 10.45 ± 0.08 and E(B −V ) = 0.185 ± 0.010, respectively) is fully consistent with that derived from main-sequence fitting techniques. Four M35 WDs may be massive enough to have oxygen-neon cores; the assumed core composition does not significantly affect the empirical IFMR. Finally, the two non-DA WDs in M35 are photometrically consistent with cluster membership; further analysis is required to determine their memberships.

Remnant planetary systems around bright white dwarfs

“…7). We compute this frequency variation with progenitor mass using the initialfinal mass functions of Kalirai et al (2008) and Williams, Bolte & Koester (2009) and find general agreement between the two. To first order, the frequency-mass dependence resembles the dependence of giant planet formation on stellar mass put forth by Kennedy & Kenyon (2008), however larger sample sizes are required to narrow the confidence intervals.…”

An extreme-AO search for giant planets around a white dwarf

“…This corresponds to a white dwarf with a mass of 1.264 M and a total age of 125 Myr, which is consistent with the age of Pleiades. According to the initial-final mass relation in Williams et al (2009), it had an initial mass of 7 M , making its progenitor a B-type star. GD 50 was chosen as our target for the SPHERE sv program due to its youth and close proximity.…”

A search for white dwarfs in the Galactic plane: the field and the open cluster population

“…García-Berro et al 1997;Williams et al 2009). The key ingredients influencing the final mass of white dwarfs are sensitive to stellar parameters like metallicity, and need to be tested on observed data.…”

“…Ground-based follow-up spectroscopy is achievable for numerous cluster white dwarfs, enabling to assess a wide range of white dwarf progenitor masses, from 1.5-2 M (e.g. Kalirai et al 2008) to 7 M , which are useful to constrain the demarcation between white dwarf and neutron star progenitors (Williams, Bolte & Koester 2009). Although the white dwarf mass distribution is quite well constrained (Tremblay et al 2013, and references therein), the general trend of the empirical initial-to-final mass relation remains approximate (Weidemann 2000), especially for low-and high-mass progenitors.…”