Constraining the Merger Fraction and the Upper Mass Limit of Ultramassive White Dwarfs

Gracyn Jewett, Mukremin Kilic, Pierre Bergeron +7

We performed a spectroscopic survey of all known white dwarfs with $M\ge 1.3M_{\odot }$ and $T_{\mathrm{eff}}\ge 11,000$ K identified through Gaia DR3 astrometry from the Gentile-Fusill…