The White Dwarf Initial-Final Mass Relation from Open Clusters in Gaia DR3

TL;DR

This paper constructs the most comprehensive empirical initial-final mass relation for white dwarfs using open clusters and Gaia DR3 data, providing new functional forms and highlighting deviations from previous models.

Contribution

It combines new spectroscopy with literature data to significantly expand the open cluster WD sample and refines the IFMR with functional forms, including Gaia-based and full samples.

Findings

Gaia-based sample includes 69 WDs, doubling previous data.

Full sample increases total cluster WDs by over 50%.

Identifies deviations from previous IFMR models, especially around 5 solar masses.

Abstract

The initial-final mass relation (IFMR) links a star's birth mass to the mass of its white dwarf (WD) remnant, providing key constraints on stellar evolution. Open clusters offer the most straightforward way to empirically determine the IFMR, as their well-defined ages allow for direct progenitor lifetime estimates. We construct the most comprehensive open cluster WD IFMR to date by combining new spectroscopy of 22 WDs with an extensive literature review of WDs with strong cluster associations. To minimize systematics, we restrict our analysis to spectroscopically confirmed hydrogen-atmosphere (DA) WDs consistent with single-stellar origins. We separately analyze a subset with reliable Gaia-based astrometric membership assessments, as well as a full sample that adds WDs with strong cluster associations whose membership cannot be reliably assessed with Gaia. The Gaia-based sample includes 69 spectroscopically confirmed DA WDs, more than doubling the sample size of previous Gaia-based open cluster IFMRs. The full sample, which includes 53 additional literature WDs, increases the total number of cluster WDs by over $50\%$ relative to earlier works. We provide functional forms for both the Gaia-based and full-sample IFMRs. The Gaia-based result useful for $M_i \geq 2.67\,\mathrm{M}_\odot$ is $$M_f = \left[0.179 - 0.100 H(M_i-3.84\,\mathrm{M}_\odot) \right ] \times (M_i-3.84\,\mathrm{M}_\odot)+0.628\,\mathrm{M}_\odot$$ where $H(x)$ is the Heaviside step function. Comparing our IFMR to recent literature, we identify significant deviations from best-fit IFMRs derived from both Gaia-based volume limited samples of field WDs and double WD binaries, with the largest discrepancy occurring for initial masses of about $5\,\mathrm{M}_\odot$.