论文标题
使用Gaia EDR3的宽双白色矮人二进制型测试白矮人年龄估计
Testing White Dwarf Age Estimates using Wide Double White Dwarf Binaries from Gaia EDR3
论文作者
论文摘要
白矮人(WD)恒星可以简单而可预测地进化,使其成为可靠的年龄指标。但是,确定WD总年龄的方法的自洽验证尚未得到广泛执行。这项工作使用1565宽(> 100个AU)WD+WD二进制文件和24个新三元组,其中包含至少两个WD,以测试WD总年龄确定的准确性和有效性。对于这1589个宽的双WD二进制文件和三元组,我们使用来自全套调查的光度数据来得出每个WD的总年龄,并结合Gaia可视性和当前的氢气大变WD模型。忽略初始质量关系,仅考虑WD冷却年龄,我们发现系统中大约21-36%的较大的WDS中的21-36%的冷却年龄较短。由于更大的WDS应该以更大的主要序列恒星的形式出生,因此我们将这种非物理分歧归因于先前合并或存在未解决的伴侣的证据,这表明大约有21-36%的WD+WD二进制文件曾经是三元。在高保真削减的423个宽WD+WD对中,我们发现总年龄不确定性通常适用于质量> 0.63 MSUN且温度<12,000 K的WD,并为更高质量WDS提供了建议的年龄不确定性的建议。总体而言,WDS返回可靠的出色年龄,但我们详细介绍了总年龄最小的案例,尤其是WDS <0.63 MSUN。
White dwarf (WD) stars evolve simply and predictably, making them reliable age indicators. However, self-consistent validation of the methods for determining WD total ages has yet to be widely performed. This work uses 1565 wide ( > 100 au) WD+WD binaries and 24 new triples containing at least two WDs to test the accuracy and validity of WD total age determinations. For these 1589 wide double-WD binaries and triples, we derive total ages of each WD using photometric data from all-sky surveys, in conjunction with Gaia parallaxes and current hydrogen-atmosphere WD models. Ignoring initial-to-final-mass relations and considering only WD cooling ages, we find that roughly 21-36% of the more massive WDs in a system have a shorter cooling age. Since more massive WDs should be born as more massive main-sequence stars, we attribute this unphysical disagreement as evidence of prior mergers or the presence of an unresolved companion, suggesting that roughly 21-36% of wide WD+WD binaries were once triples. Among the 423 wide WD+WD pairs that pass high-fidelity cuts, we find that 25% total age uncertainties are generally appropriate for WDs with masses > 0.63 Msun and temperatures < 12,000 K, and provide suggested inflation factors for age uncertainties for higher-mass WDs. Overall, WDs return reliable stellar ages, but we detail cases where total ages are least reliable, especially for WDs < 0.63 Msun.