A new detailed examination of white dwarfs in NGC3532 and NGC2287

TL;DR

This study investigates white dwarfs in open clusters NGC3532 and NGC2287, providing insights into their progenitor stars and the initial mass-final mass relation, with implications for stellar evolution models.

Contribution

It offers new observational constraints on the initial mass-final mass relation using white dwarfs in two open clusters, challenging previous evidence of scatter.

Findings

No substantial scatter in initial mass-final mass relation.

Hints at a steeper IFMR between 3 and 4 solar masses.

Supports stellar evolution models predicting a sharp drop in white dwarf mass distribution.

Abstract

We present the results of a photometric and spectroscopic study of the white dwarf candidate members of the intermediate age open clusters NGC3532 and NGC2287. Of the nine objects investigated, it is determined that six are probable members of the clusters, four in NGC3532 and two in NGC2287. For these six white dwarfs we use our estimates of their cooling times together with the cluster ages to constrain the lifetimes and masses of their progenitor stars. We examine the location of these objects in initial mass-final mass space and find that they now provide no evidence for substantial scatter in initial mass-final mass relation as suggested by previous investigations. Instead, we demonstrate that, when combined with current data from other solar metalicity open clusters and the Sirius binary system, they hint at an IFMR that is steeper in the initial mass range 3M$_{\odot}$$\simless$M$_{\rm init}$$\simless$4M$_{\odot}$ than at progenitor masses immediately lower and higher than this. This form is generally consistent with the predictions of stellar evolutionary models and can aid population synthesis models in reproducing the relatively sharp drop observed at the high mass end of the main peak in the mass distribution of white dwarfs.