论文标题
超级白矮人的合并部分
The Merger Fraction of Ultramassive White Dwarfs
论文作者
论文摘要
我们通过随访光谱和高添加度光度法在蒙特利尔白矮人数据库100 PC样本中搜索25个最大的白色矮人中的合并产品。我们发现该人群中异常高的磁白矮人中的40％。此外，我们确定了横向速度的四个异常值，并检测五个物体的快速旋转。我们的结果表明，$ 56^{+9} _ { - 10} $ \％$ m \ oft1.3〜m _ {\ odot} $通过合并形式的超大白矮人形式。使用$α$ -PRESCRIPTION（$αλ= 2 $）的默认二元种群合成计算中的默认二进制群体合成计算的预期，该部分明显高于预期，并为有效的轨道收缩提供了进一步的支持，例如公共信封效率较低的值。
We search for merger products among the 25 most massive white dwarfs in the Montreal White Dwarf Database 100 pc sample through follow-up spectroscopy and high-cadence photometry. We find an unusually high fraction, 40%, of magnetic white dwarfs among this population. In addition, we identify four outliers in transverse velocity and detect rapid rotation in five objects. Our results show that $56^{+9}_{-10}$\% of the $M\approx1.3~M_{\odot}$ ultramassive white dwarfs form through mergers. This fraction is significantly higher than expected from the default binary population synthesis calculations using the $α$-prescription (with $αλ= 2$), and provides further support for efficient orbital shrinkage, such as with low values of the common envelope efficiency.
